Exhibit 4.1

Execution Version

OMNICOM GROUP INC.

as Issuer

FIFTH SUPPLEMENTAL INDENTURE

Dated as of December 2, 2025

DEUTSCHE BANK TRUST COMPANY AMERICAS

as Trustee

Debt Securities

Fifth Supplemental Indenture dated as of December 2, 2025 (the “Fifth Supplemental Indenture”) between Omnicom Group Inc., a New York corporation (the “Issuer”) and Deutsche Bank Trust Company Americas, a New York banking corporation, as Trustee (the “Trustee”).

W I T N E S S E T H:

WHEREAS, the Issuer and the Trustee executed and delivered an indenture dated as of February 21, 2020 (the “Indenture”) to provide for the issuance by the Issuer from time to time of Securities to be issued in one or more Series as provided in the Indenture;

WHEREAS, the issuance of up to $500,000,000 aggregate principal amount of a Series of the Issuer’s 4.650% Senior Notes due 2028 (the “2028 Notes”), $650,000,000 aggregate principal amount of a Series of the Issuer’s 4.750% Senior Notes due 2030 (the “2030 Notes”), $500,000,000 aggregate principal amount of a Series of the Issuer’s 2.400% Senior Notes due 2031 (the “2031 Notes”), $300,000,000 aggregate principal amount of a Series of the Issuer’s 5.375% Senior Notes due 2033 (the “2033 Notes”), $500,000,000 aggregate principal amount of a Series of the Issuer’s 3.375% Senior Notes due 2041 (the “2041 Notes”), and $500,000,000 aggregate principal amount of a Series of the Issuer’s 5.400% Senior Notes due 2048 (the “2048 Notes” and, together with the 2028 Notes, the 2030 Notes, the 2031 Notes, the 2033 Notes and the 2041 Notes, the “Securities”) have been authorized by the board of directors of the Issuer;

WHEREAS, on the date hereof, the Issuer desires to issue $451,426,000 aggregate principal amount of the 2028 Notes, $591,859,000 aggregate principal amount of the 2030 Notes; $457,358,000 aggregate principal amount of the 2031 Notes, $278,341,000 aggregate principal amount of the 2033 Notes, $494,331,000 aggregate principal amount of the 2041 Notes and $491,657,000 aggregate principal amount of the 2048 Notes.

WHEREAS, the Issuer desires to enter into this Fifth Supplemental Indenture pursuant to Sections 2.2, 2.14.1 and 9.1 of the Indenture to supplement the Indenture to establish the form and terms of the Securities and amend the Indenture with respect to the Securities to be issued hereunder as provided below; and

NOW, THEREFORE, THIS FIFTH SUPPLEMENTAL INDENTURE WITNESSETH, that, for and in consideration of the above premises, it is mutually covenanted and agreed, for the sole, equal and proportionate benefit of all Holders of the Securities, as follows:

ARTICLE ONE

DEFINITIONS

Section 1.1 Relation to Base Indenture.  

This Fifth Supplemental Indenture constitutes an integral part of the Indenture. In the event of inconsistencies between the Indenture and this Fifth Supplemental Indenture, the terms hereof shall govern.

Section 1.2. Definitions.

(a) All of the terms used in this Fifth Supplemental Indenture which are defined in the Indenture shall have the meanings specified in the Indenture, unless otherwise provided herein or unless the context otherwise requires, and for the purposes of this Fifth Supplemental Indenture and the Securities, the following terms have the meanings set forth in this Section:

“Applicable Procedures” means, with respect to any transfer or exchange of or for beneficial interests in any Global Securities, the rules and procedures of the Depositary, Euroclear and/or Clearstream that apply to such transfer or exchange.

“Below Investment Grade Rating Event” occurs if both the rating on the applicable Series of Securities is lowered by each of the Rating Agencies and such Securities are rated below Investment Grade by each of the Rating Agencies on any date from the date of the public notice of an arrangement that could result in a Change of Control until the end of the 60-day period following public notice of the occurrence of a Change of Control (which period shall be extended so long as the rating of the applicable Series of Securities is under publicly announced consideration for possible downgrade by any of the Rating Agencies); provided that a Below Investment Grade Rating Event otherwise arising by virtue of a particular reduction in rating shall not be deemed to have occurred in respect of a particular Change of Control (and thus shall not be deemed a Below Investment Grade Rating Event for purposes of the definition of Change of Control Triggering Event hereunder) if any of the Rating Agencies making the reduction in rating to which this definition would otherwise apply does not announce or publicly confirm or inform the Trustee in writing at its request that the reduction was the result, in whole or in part, of any event or circumstance comprised of or arising as a result of, or in respect of, the applicable Change of Control (whether or not the applicable Change of Control shall have occurred at the time of the Below Investment Grade Rating Event).

“Change of Control” means the occurrence of any of the following:

Notwithstanding the foregoing, a transaction will not be deemed to involve a Change of Control if (i) the Issuer becomes a wholly owned Subsidiary of a holding company and (ii) the holders of the Voting Stock of such holding company immediately following such transaction are substantially the same as the holders of the Issuer’s Voting Stock immediately prior to such transaction.

“Change of Control Offer” has the meaning specified in Section 3.2 of this Fifth Supplemental Indenture.

“Change of Control Payment Date” has the meaning specified in Section 3.2 of this Fifth Supplemental Indenture.

“Change of Control Purchase Price” has the meaning specified in Section 3.2 of this Fifth Supplemental Indenture.

“Change of Control Triggering Event” means the occurrence of both a Change of Control and a Below Investment Grade Rating Event.

“Clearstream” has the meaning specified in Section 2.1.11(c) of this Fifth Supplemental Indenture.

“Commission” means the U.S. Securities and Exchange Commission.

“Consolidated Net Worth” means the consolidated net worth of the Issuer, as determined in accordance with GAAP.

“Debt” of any person means, without duplication: (a) all indebtedness of such person for borrowed money; (b) all obligations of such person for the deferred purchase price of property or services (other than earn-out payment obligations of such Person in connection with the purchase of property or services to the extent they are still contingent); (c) all obligations of such person evidenced by notes, bonds, debentures or other similar instruments; (d) all obligations of such person created or arising under any conditional sale or other title retention agreement with respect to property acquired by such person (even though the rights and remedies of the seller or lender under such agreement in the event of default are limited to repossession or sale of such property); (e) all obligations of such person as lessee under leases to the extent that such leases have been or should be, in accordance with GAAP, recorded as finance leases; (f) all obligations, contingent or otherwise, of such person in respect of acceptances, letters of credit or similar extensions of credit; (g) all obligations of such person in respect of Hedge Agreements; (h) all Debt of others referred to in clauses (a) through (g) above or clause (i) below and other payment obligations guaranteed, directly or indirectly, in any manner by such person, or in effect guaranteed, directly or indirectly, by such person through an agreement (1) to pay or purchase such Debt or to advance or supply funds for the payment or purchase of such Debt, (2) to purchase, sell or lease (as lessee or lessor) property, or to purchase or sell services, primarily for the purpose of enabling the debtor to make payment of such Debt or to assure the holder of such Debt against loss, (3) to supply funds to or in any other manner invest in the debtor (including any agreement to pay for property or services irrespective of whether such property is received or such services are rendered) or (4) otherwise to assure a creditor against loss; and (i) all Debt referred to in clauses (a) through (h) above secured by (or for which the holder of such Debt has an existing right, contingent or otherwise, to be secured by) any Lien on property (including, without limitation, accounts and contract rights) owned by such person, even though such person has not assumed or become liable for the payment of such Debt.

“Euroclear” has the meaning specified in Section 2.1.11(c) of this Fifth Supplemental Indenture.

“Exchange Notes” means the Securities of a Series issued pursuant to the Indenture in exchange for, and in an aggregate principal amount not to exceed, such Securities in compliance with the terms of the Registration Rights Agreement and containing terms substantially identical to such Securities (except that such Exchange Notes will be registered under the Securities Act and will not be subject to transfer restrictions or bear a Restricted Notes Legend).

“Exchange Offer” means an offer by the Issuer to the Holders of the Securities to exchange outstanding Securities for Exchange Notes, as provided for in the Registration Rights Agreement.

“GAAP” means generally accepted accounting principles in the United States of America.

“Hedge Agreements” means interest rate swap, cap or collar agreements, interest rate future or option contracts, currency swap agreements, currency future or option contracts and other similar agreements.

“interest payment date” when used with respect to any Security, means the Stated Maturity of an installment of interest on such Security.

“Investment Grade” means a rating equal to or higher than Baa3 (or its equivalent under any successor rating categories) by Moody’s and BBB- (or its equivalent under any successor rating categories) by S&P, or, in each case, if such Rating Agency ceases to rate the applicable Series of Securities or fails to make a rating of such Series of Securities publicly available for reasons outside of the Issuer’s control, the equivalent investment grade credit rating by the replacement agency selected by the Issuer in accordance with the procedures described under clause (2) of the definition of “Rating Agencies.”

“Lien” means any lien, security interest or other charge or encumbrance of any kind, or any other type of preferential arrangement intended to provide security for the payment or performance of an obligation, including, without limitation, the lien or retained security title of a conditional vendor and any easement, right of way or other encumbrance on title to real property.

“Moody’s” means Moody’s Investors Service, Inc., and its successors.

“Non-U.S. Person” means a person who is not a “U.S. Person” as such term is defined in Regulation S.

“Par Call Date” means:

for the 2028 Notes, July 1, 2028;

for the 2030 Notes, December 30, 2029;

for the 2031 Notes, December 1, 2030;

for the 2033 Notes, March 15, 2033;

for the 2041 Notes, September 1, 2040; and

for the 2048 Notes, April 1, 2048.

“Permitted Liens” means such of the following as to which no enforcement, collection, execution, levy or foreclosure proceeding shall have been commenced: (a) Liens for taxes, assessments and governmental charges or levies to the extent not yet due and payable, or being contested in good faith by appropriate proceedings; (b) Liens imposed by law, such as materialmen’s, mechanics’, carriers’, workmen’s and repairmen’s Liens and other similar Liens arising in the ordinary course of business securing obligations that are not overdue for a period of more than 30 days or that are being contested in good faith and by appropriate proceedings that prevent the forfeiture or sale of the asset subject to such Lien; (c) pledges or deposits to secure obligations under workers’ compensation laws or similar legislation or to secure public or statutory obligations or, in any such case, to secure reimbursement obligations under letters of credit or bonds issued to support such obligations; and (d) easements, rights of way and other encumbrances on title to real property that do not render title to the property encumbered thereby unmarketable or materially adversely affect the use of such property for its present purposes.

“QIB” means a “Qualified Institutional Buyer” as defined in Rule 144A.

“Rating Agencies” means (1) each of Moody’s and S&P; and (2) if any of Moody’s or S&P ceases to rate the applicable Series of Securities or fails to make a rating of the applicable Series of Securities publicly available for reasons outside of the Issuer’s control, a “nationally recognized statistical rating organization,” as defined in Section 3(a)(62) of the Exchange Act, selected by the Issuer as a replacement agency for Moody’s or S&P, or both of them, as the case may be.

“record date” as used with respect to any interest payment date (except a date for payment of defaulted interest) for the Securities of any Series shall mean the date specified as such in the terms of the Registered Securities of such Series established, or, if no such date is so established, the fifteenth day next preceding such interest payment date, whether or not such record date is a Business Day.

“Registration Rights Agreement” means the registration rights agreement, dated as of December 2, 2025, among the Issuer and BofA Securities, Inc., J.P. Morgan Securities LLC, Wells Fargo Securities, LLC, Barclays Capital Inc., BNP Paribas Securities Corp., Citigroup Global Markets Inc., Deutsche Bank Securities Inc. and HSBC Securities (USA) Inc.

“Regulation S” means Regulation S under the Securities Act (including any successor regulation thereto), as it may be amended from time to time.

“Regulation S Global Note” has the meaning specified in Section 2.1.11(c) of this Fifth Supplemental Indenture.

“Regulation S Notes” has the meaning specified in Section 2.1.11(c) of this Fifth Supplemental Indenture.

“Restricted Notes Legend” means the legend set forth in Section 2.1.11(d) of this Fifth Supplemental Indenture.

“Restricted Period” has the meaning specified in Section 2.1.11(c) of this Fifth Supplemental Indenture.

“Rule 144” means Rule 144 under the Securities Act (including any successor regulation thereto), as it may be amended from time to time.

“Rule 144A” means Rule 144A under the Securities Act (including any successor regulation thereto), as it may be amended from time to time.

“Rule 144A Global Note” has the meaning specified in Section 2.1.11(b) of this Fifth Supplemental Indenture.

“Rule 144A Notes” has the meaning specified in Section 2.1.11(b) of this Fifth Supplemental Indenture.

“Securities Act” means the U.S. Securities Act of 1933, as amended, or any successor statute, and the rules and regulations promulgated by the Commission thereunder.

“S&P” means S&P Global Ratings, and its successors.

“Treasury Rate” means, with respect to any redemption date, the yield determined by the Issuer after 4:15 p.m., New York City time (or after such time as yields on U.S. government securities are posted daily by the Board of Governors of the Federal Reserve System), on the third Business Day preceding the redemption date based upon the yield or yields for the most recent day that appear after such time on such day in the most recent statistical release published by the Board of Governors of the Federal Reserve System designated as “Selected Interest Rates (Daily) — H.15” (or any successor designation or publication) (“H.15”) under the caption “U.S. government securities — Treasury constant maturities — Nominal” (or any successor caption or heading) (“H.15 TCM”). In determining the Treasury Rate, the Issuer shall select, as applicable: (1) the yield for the Treasury constant maturity on H.15 exactly equal to the period from the redemption date to the applicable Par Call Date (the “Remaining Life”); or (2) if there is no such Treasury constant maturity on H.15 exactly equal to the Remaining Life, the two yields — one yield corresponding to the Treasury constant maturity on H.15 immediately shorter than and one yield corresponding to the Treasury constant maturity on H.15 immediately longer than the Remaining Life — and shall interpolate to the applicable Par Call Date on a straight-line basis (using the actual number of days) using such yields and rounding the result to three decimal places; or (3) if there is no such Treasury constant maturity on H.15 shorter than or longer than the Remaining Life, the yield for the single Treasury constant maturity on H.15 closest to the Remaining Life. For purposes of this paragraph, the applicable Treasury constant maturity or maturities on H.15 shall be deemed to have a maturity date equal to the relevant number of months or years, as applicable, of such Treasury constant maturity from the redemption date. If on the third Business Day preceding the redemption date H.15 TCM is no longer published, the Issuer shall calculate the Treasury Rate based on the rate per annum equal to the semi-annual equivalent yield to maturity at 11:00 a.m., New York City time, on the second Business Day preceding such redemption date of the United States Treasury security maturing on, or with a maturity that is closest to, the applicable Par Call Date, as applicable. If there is no United States Treasury security maturing on the applicable Par Call Date but there are two or more United States Treasury securities with a maturity date equally distant from the applicable Par Call Date, one with a maturity date preceding the applicable Par Call Date and one with a maturity date following the applicable Par Call Date, the Issuer shall select the United States Treasury security with a maturity date preceding the applicable Par Call Date. If there are two or more United States Treasury securities maturing on the applicable Par Call Date or two or more United States Treasury securities meeting the criteria of the preceding sentence, the Issuer shall select from among these two or more United States Treasury securities the United States Treasury security that is trading closest to par based upon the average of the bid and asked prices for such United States Treasury securities at 11:00 a.m., New York City time. In determining the Treasury Rate in accordance with the terms of this paragraph, the semi-annual yield to maturity of the applicable United States Treasury security shall be based upon the average of the bid and asked prices (expressed as a percentage of principal amount) at 11:00 a.m., New York City time, of such United States Treasury security, and rounded to three decimal places.

“Voting Stock” means, with respect to any person, capital stock of any class or kind the holders of which are ordinarily, in the absence of contingencies, entitled to vote for the election of directors (or persons performing similar functions) of such person, even if the right so to vote has been suspended by the happening of such a contingency.

ARTICLE TWO

THE SECURITIES. AMENDMENTS TO THE INDENTURE

Section 2.1. Terms of the Securities.

The Securities shall have the following terms, established pursuant to Section 2.2 of the Indenture:

2.1.1. Pursuant to Section 2.2.1 of the Indenture, and in each case to be issued as a Series of Securities under the Indenture:

the title of the 2028 Notes shall be the “4.650% Senior Notes due 2028”;

the title of the 2030 Notes shall be the “4.750% Senior Notes due 2030”;

the title of the 2031 Notes shall be the “2.400% Senior Notes due 2031”;

the title of the 2033 Notes shall be the “5.375% Senior Notes due 2033”;

the title of the 2041 Notes shall be the “3.375% Senior Notes due 2041”; and

the title of the 2048 Notes shall be the “5.400% Senior Notes due 2048”.

2.1.2. Pursuant to Section 2.2.2 of the Indenture, the price or prices at which the Securities of the Series will be issued initially shall be 100% of the aggregate principal amount thereof;

2.1.3. Pursuant to Section 2.2.3 of the Indenture, the aggregate principal amount of the Securities that may be authenticated and delivered under this Fifth Supplemental Indenture initially shall be limited to:

for the 2028 Notes, $451,426,000;

for the 2030 Notes, $591,859,000;

for the 2031 Notes, $457,358,000;

for the 2033 Notes, $278,341,000;

for the 2041 Notes, $494,331,000; and

for the 2048 Notes, $491,657,000.

2.1.4. Pursuant to Section 2.2.4 of the Indenture:

100% of the 2028 Notes shall be payable on October 1, 2028;

100% of the 2030 Notes shall be payable on March 30, 2030;

100% of the 2031 Notes shall be payable on March 1, 2031;

100% of the 2033 Notes shall be payable on June 15, 2033;

100% of the 2041 Notes shall be payable on March 1, 2041; and

100% of the 2048 Notes shall be payable on October 1, 2048;

2.1.5. Pursuant to Section 2.2.5 of the Indenture, the Securities shall bear interest at a rate equal to:

4.650% per annum for the 2028 Notes;

4.750% per annum for the 2030 Notes;

2.400% per annum for the 2031 Notes;

5.375% per annum for the 2033 Notes;

3.375% per annum for the 2041 Notes; and

5.400% per annum for the 2048 Notes;

interest on the Securities shall accrue from:

for the 2028 Notes, October 1, 2025;

for the 2030 Notes, September 30, 2025;

for the 2031 Notes, September 1, 2025;

for the 2033 Notes, June 15, 2025;

for the 2041 Notes, September 1, 2025; and

for the 2048 Notes, October 1, 2025;

in each case, until the principal thereof is paid or duly provided for;

interest on the Securities shall be payable semi-annually in arrears in cash on:

for the 2028 Notes, April 1 and October 1 of each year, commencing on April 1, 2026;

for the 2030 Notes, March 30 and September 30 of each year, commencing on March 30, 2026;

for the 2031 Notes, March 1 and September 1 of each year, commencing on March 1, 2026;

for the 2033 Notes, June 15 and December 15 of each year, commencing on December 15, 2025;

for the 2041 Notes, March 1 and September 1 of each year, commencing on March 1, 2026; and

for the 2048 Notes, April 1 and October 1 of each year, commencing on April 1, 2026; and interest shall be payable to Holders of record on, in each case, whether or not a Business Day:

for the 2028 Notes, March 15 and September 15 immediately preceding the applicable interest payment date;

for the 2030 Notes, March 15 and September 15 immediately preceding the applicable interest payment date;

for the 2031 Notes, February 15 and August 15 immediately preceding the applicable interest payment date;

for the 2033 Notes, June 1 and December 1 immediately preceding the applicable interest payment date;

for the 2041 Notes, February 15 and August 15 immediately preceding the applicable interest payment date; and

for the 2048 Notes, March 15 and September 15 immediately preceding the applicable interest payment date.

Interest on the Securities shall be computed from and including the prior interest payment date or, in the case of the first interest payment date, from and including:

for the 2028 Notes, October 1, 2025;

for the 2030 Notes, September 30, 2025;

for the 2031 Notes, September 1, 2025;

for the 2033 Notes, June 15, 2025;

for the 2041 Notes, September 1, 2025; and

for the 2048 Notes, October 1, 2025,

to but excluding the next interest payment date on the basis of a 360-day year consisting of twelve 30-day months.

In the event that any principal or interest on the applicable Series of Securities is not paid when due, whether at Maturity or otherwise, then except to the extent permitted by law such overdue principal and interest shall bear interest until paid at the rate of interest set forth in this Section 2.1.5 of this Fifth Supplemental Indenture, compounded semi-annually;

2.1.6. Pursuant to Section 2.2.6 of the Indenture, the place or places where the principal of and interest in the Securities shall be payable shall be as set forth in the Securities;

2.1.7. Pursuant to Section 2.2.7 of the Indenture, the Securities shall be subject to redemption at the option of the Issuer as set forth in Article III of the Indenture, as modified by Section 3.1 of this Fifth Supplemental Indenture;

2.1.8. Pursuant to Section 2.2.8 of the Indenture, the Issuer shall not be obligated to redeem or purchase the Securities pursuant to any sinking fund or at the option of a Holder thereof prior to the Maturity;

2.1.9. Pursuant to Section 2.2.9 of the Indenture, the Issuer shall not be obligated to redeem or purchase the Securities pursuant to any repurchase obligations or at the option of a Holder thereof prior to the Maturity, except pursuant to Section 3.2 of this Fifth Supplemental Indenture;

2.1.10. Pursuant to Section 2.2.10, the Securities shall be issuable in denominations of $2,000 and integral multiples of $1,000 in excess thereof;

2.1.11. (a) Pursuant to Section 2.2.11 of the Indenture, the Securities shall be issued as Global Securities, the forms of which are attached hereto as Exhibit A, Exhibit B, Exhibit C, Exhibit D, Exhibit E and Exhibit F;

(b) The Securities issued to QIBs in the United States of America in reliance on Rule 144A (the “Rule 144A Notes”) shall be issued in the form of a permanent Global Security substantially in the form of Exhibit A, Exhibit B, Exhibit C, Exhibit D, Exhibit E and Exhibit F hereto (the “Rule 144A Global Note”) and shall be deposited on issuance with, or on behalf of, the Trustee, as custodian for the Depository, and registered in the name of the Depository or its nominee.

(c) The Securities issued outside the United States of America in reliance on Regulation S (the “Regulation S Notes”) shall initially be issued in the form of a permanent Global Security substantially in the form of Exhibit A, Exhibit B, Exhibit C, Exhibit D, Exhibit E and Exhibit F hereto (the “Regulation S Global Note”) and shall be deposited upon issuance with, or on behalf of, the Trustee as custodian for the Depository, and registered in the name of the Depository or its nominee, in the manner described in the Indenture for credit to the respective accounts of the purchasers (or to such other accounts as they may direct), including, but not limited to, accounts at Euroclear Bank SA/NV (“Euroclear”) or Clearstream Banking, S.A. (“Clearstream”). Prior to the 40th day after the date hereof (such period through and including such 40th day, the “Restricted Period”), interests in the Regulation S Global Notes may only be transferred to Non-U.S. Persons pursuant to Regulation S, unless exchanged for interests in a Rule 144A Global Note in accordance with the transfer and certification requirements described herein.

Holders may hold their interests in the Regulation S Global Note through organizations other than Euroclear or Clearstream that are participants in Depository’s system or directly through Euroclear or Clearstream, if they are participants in such systems. If such interests are held through Euroclear or Clearstream, Euroclear and Clearstream will hold such interests in the applicable Regulation S Global Note on behalf of their participants through customers’ securities accounts in their respective names on the books of their respective depositaries. Such depositaries, in turn, will hold such interests in the applicable Regulation S Global Note in customers’ securities accounts in the depositaries’ names on the books of the Depository.

(d) Except as provided pursuant to Section 2.1.11(g) of this Fifth Supplemental Indenture, each Security issued in reliance on an exemption from the registration requirements of the Securities Act shall bear the following legend on the face thereof (which, for the avoidance of doubt, shall be in addition to any legend required under Section 2.14.3 of the Base Indenture):

“THIS SECURITY HAS NOT BEEN REGISTERED UNDER THE SECURITIES ACT, AND MAY NOT BE OFFERED, SOLD, PLEDGED OR OTHERWISE TRANSFERRED EXCEPT IN ACCORDANCE WITH THE FOLLOWING SENTENCE. BY ITS ACQUISITION HEREOF OR OF A BENEFICIAL INTEREST HEREIN, THE ACQUIRER

(1) REPRESENTS THAT

(A) IT AND ANY ACCOUNT FOR WHICH IT IS ACTING IS A “QUALIFIED INSTITUTIONAL BUYER” (WITHIN THE MEANING OF RULE 144A UNDER THE SECURITIES ACT) AND THAT IT EXERCISES SOLE INVESTMENT DISCRETION WITH RESPECT TO EACH SUCH ACCOUNT, OR

(B) IT IS NOT A “U.S. PERSON” NOR IS IT ACTING FOR THE ACCOUNT OR BENEFIT OF ANY “U.S. PERSON” (EACH WITHIN THE MEANING OF REGULATION S UNDER THE SECURITIES ACT) AND

(2) AGREES FOR THE BENEFIT OF THE ISSUER THAT IT WILL NOT OFFER, SELL, PLEDGE OR OTHERWISE TRANSFER THIS SECURITY OR ANY BENEFICIAL INTEREST HEREIN, EXCEPT IN ACCORDANCE WITH THE SECURITIES ACT AND ANY APPLICABLE SECURITIES LAWS OF ANY STATE OF THE UNITED STATES AND ONLY

(A) TO THE ISSUER,

(B) PURSUANT TO A REGISTRATION STATEMENT WHICH HAS BECOME EFFECTIVE UNDER THE SECURITIES ACT,

(C) TO A QUALIFIED INSTITUTIONAL BUYER IN COMPLIANCE WITH RULE 144A UNDER THE SECURITIES ACT, (D) IN AN OFFSHORE TRANSACTION IN COMPLIANCE WITH RULE 904 OF REGULATION S UNDER THE SECURITIES ACT,

(E) TO AN INSTITUTIONAL “ACCREDITED INVESTOR” WITHIN THE MEANING OF RULE 501(a)(1), (2), (3) OR (7) UNDER THE SECURITIES ACT THAT IS NOT A QUALIFIED INSTITUTIONAL BUYER AND THAT IS PURCHASING FOR ITS OWN ACCOUNT OR FOR THE ACCOUNT OF ANOTHER INSTITUTIONAL ACCREDITED INVESTOR, IN EACH CASE IN A MINIMUM PRINCIPAL AMOUNT OF SECURITIES OF $250,000, OR

(F) PURSUANT TO AN EXEMPTION FROM REGISTRATION PROVIDED BY RULE 144 UNDER THE SECURITIES ACT OR ANY OTHER AVAILABLE EXEMPTION FROM THE REGISTRATION REQUIREMENTS OF THE SECURITIES ACT.

PRIOR TO THE REGISTRATION OF ANY TRANSFER IN ACCORDANCE WITH (2)(C) ABOVE OR (2)(D) ABOVE, A DULY COMPLETED AND SIGNED CERTIFICATE (THE FORM OF WHICH IS ATTACHED AS EXHIBIT G TO THE FIFTH SUPPLEMENTAL INDENTURE OF THE ISSUER) MUST BE DELIVERED TO THE TRUSTEE. PRIOR TO THE REGISTRATION OF ANY TRANSFER IN ACCORDANCE WITH (F) ABOVE, THE ISSUER RESERVES THE RIGHT TO REQUIRE THE DELIVERY OF SUCH LEGAL OPINIONS, CERTIFICATIONS OR OTHER EVIDENCE AS MAY REASONABLY BE REQUIRED IN ORDER TO DETERMINE THAT THE PROPOSED TRANSFER IS BEING MADE IN COMPLIANCE WITH THE SECURITIES ACT AND APPLICABLE STATE SECURITIES LAWS. NO REPRESENTATION IS MADE AS TO THE AVAILABILITY OF ANY RULE 144 EXEMPTION FROM THE REGISTRATION REQUIREMENTS OF THE SECURITIES ACT.”

(e) Transfers of Rule 144A Notes. The following provisions shall apply with respect to any proposed registration of transfer of a Rule 144A Note prior to the date which is one year after the later of the date hereof and the last date on which the Issuer or any Affiliate of the Issuer was the owner of such Securities or the relevant beneficial interest therein (or any predecessor thereto):

(1) a registration of transfer of a Rule 144A Note or a beneficial interest therein to a QIB pursuant to Rule 144A shall be made upon the representation of the transferee, in the form of assignment as set forth on the reverse of the Securities, that it is purchasing for its own account or an account with respect to which it exercises sole investment discretion and that it and any such account is a “qualified institutional buyer” within the meaning of Rule 144A, and is aware that the sale to it is being made in reliance on Rule 144A and acknowledges that it has received such information regarding the Issuer as the transferee has requested pursuant to Rule 144A or has determined not to request such information and that it is aware that the transferor is relying upon its foregoing representations in order to claim the exemption from registration provided by Rule 144A;

(2) a registration of transfer of a Rule 144A Note or a beneficial interest therein to a Non-U.S. Person pursuant to Regulation S shall be made upon receipt by the Trustee or its agent of a certificate substantially in the form set forth in Exhibit G from the proposed transferor (which the Trustee may conclusively rely upon and shall have no responsibility (or any liability) to verify or ensure the accuracy of the information contained therein); and

(3) in connection with a registration of transfer of a Rule 144A Note or a beneficial interest therein pursuant to an exemption from registration provided by Rule 144 or any other available exemption from the registration requirements of the Securities Act (other than pursuant to Rule 144A or Regulation S), the Issuer may require, prior to registering any such transfer, in its sole discretion, such legal opinions, certifications and other information as the Issuer may reasonably request to confirm that such transfer is being made pursuant to an exemption from, or in a transaction not subject to, the registration requirements of the Securities Act, such as the exemption provided by Rule 144.

(f) Transfers of Regulations S Notes. The following provisions shall apply with respect to any proposed registration of transfer of a Regulation S Note prior to the expiration of the Restricted Period:

(1) a registration of transfer of a Regulation S Note or a beneficial interest therein to a QIB pursuant to Rule 144A shall be made upon the representation of the transferee, in the form of assignment as set forth on the reverse of the Securities, that it is purchasing the applicable Security for its own account or an account with respect to which it exercises sole investment discretion and that it and any such account is a QIB, is aware that the sale to it is being made in reliance on Rule 144A and acknowledges that it has received such information regarding the Issuer as the transferee has requested pursuant to Rule 144A or has determined not to request such information and that it is aware that the transferor is relying upon its foregoing representations in order to claim the exemption from registration provided by Rule 144A;

(2) a registration of transfer of a Regulation S Note or a beneficial interest therein to a Non-U.S. Person pursuant to Regulation S shall be made upon receipt by the Trustee or its agent of a certificate substantially in the form set forth in Exhibit G from the proposed transferor (which the Trustee may conclusively rely upon and shall have no responsibility (or any liability) to verify or ensure the accuracy of the information contained therein); and

(3) in connection with a registration of transfer of a Regulation S Note or a beneficial interest therein pursuant to an exemption from registration provided by Rule 144 or any other available exemption from the registration requirements of the Securities Act (other than pursuant to Rule 144A or Regulation S), the Issuer may require, prior to registering any such transfer, in its sole discretion, such legal opinions, certifications and other information as the Issuer may reasonably request to confirm that such transfer is being made pursuant to an exemption from, or in a transaction not subject to, the registration requirements of the Securities Act, such as the exemption provided by Rule 144.

After the expiration of the Restricted Period, interests in the Regulation S Note may be transferred in accordance with applicable law without requiring the certification set forth in Exhibit G or any additional certification.

(g) Restricted Notes Legend. Upon the transfer, exchange or replacement of Securities not bearing a Restricted Notes Legend, the Registrar shall deliver Securities that do not bear a Restricted Notes Legend. Upon the transfer, exchange or replacement of Securities bearing a Restricted Notes Legend, the Registrar shall deliver only Securities that bear a Restricted Notes Legend unless (i) the Securities are being transferred pursuant to an effective registration statement (pursuant to the Registration Rights Agreement or otherwise), (ii) the Securities are validly tendered for exchange into Exchange Notes pursuant to an Exchange Offer or (iii) there is delivered to the Registrar an Opinion of Counsel reasonably satisfactory to the Issuer and the Trustee to the effect that neither such legend nor the related restrictions on transfer are required in order to maintain compliance with the provisions of the Securities Act.

(l) Exchange Offer. Upon the occurrence of an Exchange Offer in accordance with the Registration Rights Agreement, the Issuer shall issue and, upon receipt of a written order and the other documents required by the Indenture, the Trustee shall authenticate one or more Global Securities not bearing the Restricted Notes Legend in an aggregate principal amount equal to the principal amount of the beneficial interests in the Securities tendered for acceptance in the Exchange Offer by each person in accordance with the Depository’s Applicable Procedures. Concurrently with the issuance of such Global Securities, the Trustee shall cause the aggregate principal amount of the applicable Global Securities bearing the Restricted Notes Legend to be reduced accordingly. Any Securities that remain outstanding after the consummation of an Exchange Offer, and Exchange Notes issued in connection with such Exchange Offer, shall be treated as a single class of securities under the Indenture.

2.1.12. Pursuant to Section 2.2.15 of the Indenture, the Issuer shall be subject to the additional restrictions as set forth in Section 4.1 of this Fifth Supplemental Indenture; and

2.1.13. Pursuant to Section 2.2 of the Indenture, the Issuer may, without the consent of the Holders of the Securities of any Series, issue additional Securities of such Series having the same ranking and the same interest rate, maturity and other terms as the Securities of such Series issued on the date hereof (except for the issue date, the price to the public, the payment of interest accruing prior to the issue date of such additional Securities and the first payment of interest following the issue date of such additional Securities). Any such additional Securities shall be a part of the Series having the same terms as the Securities of such Series issued on the date hereof, provided that such additional Securities subsequently issued are fungible for U.S. federal income tax purposes with any Securities of such Series previously issued.

Section 2.3. Amendments to the Indenture. The Indenture is hereby amended with respect to the Securities only as follows:

ARTICLE THREE

ADDITIONAL REDEMPTION PROVISION

Section 3.1. Optional Redemption.

Prior to the applicable Par Call Date, the Issuer may redeem such Series of Securities at its option, in whole or in part, at any time and from time to time, at a redemption price (expressed as a percentage of principal amount and rounded to three decimal places) equal to the greater of:

25 basis points with respect to the 2028 Notes;

50 basis points with respect to the 2030 Notes;

20 basis points with respect to the 2031 Notes;

30 basis points with respect to the 2033 Notes;

25 basis points with respect to the 2041 Notes; and

35 basis points with respect to the 2048 Notes;

less (ii) interest accrued to the date of redemption, and On or after the applicable Par Call Date, the Issuer may redeem the applicable Series of Securities, in whole or in part, at any time and from time to time, at a redemption price equal to 100% of the principal amount of such Securities being redeemed plus accrued and unpaid interest thereon to the redemption date.

Notice of any redemption will be mailed or electronically delivered (or otherwise transmitted in accordance with the Depository’s procedures) at least 10 days but not more than 60 days before the redemption date to each Holder of the applicable Series of the Securities to be redeemed at its registered address.

The Issuer’s actions and determinations in determining the redemption price shall be conclusive and binding for all purposes, absent manifest error. The calculation or determination of the redemption price shall be made by the Issuer or on its behalf by such person as the Issuer shall designate. For the avoidance of doubt, the calculation or determination of the redemption price, including the determination of any Treasury Rate, shall not be the obligation or responsibility of the Trustee or Paying Agent.

On and after the redemption date, interest shall cease to accrue on the applicable Series of Securities or any portion of such Securities called for redemption (unless the Issuer defaults in the payment of the redemption price and accrued interest). On or before 10:00 a.m. New York City time on the redemption date, the Issuer shall deposit with a Paying Agent (or the Trustee, if other than the Paying Agent) money sufficient to pay the redemption price of and accrued interest on the applicable Series of the Securities to be redeemed on that date.

If less than all of the applicable Series of Securities are to be redeemed, such Securities to be redeemed shall be selected by such method as the Trustee deems fair and appropriate, subject to the procedures of the Depository.

Section 3.2. Repurchase Upon Change of Control Triggering Event.

Upon the occurrence of a Change of Control Triggering Event, unless the Issuer has exercised its option to redeem the applicable Series of the Securities pursuant to Section 3.1 of this Fifth Supplemental Indenture, each Holder of such Securities shall have the right to require the Issuer to repurchase all or a portion of such Holder’s Securities pursuant to a change of control offer pursuant to, and in accordance with, the provisions of this Section 3.2 (a “Change of Control Offer”), at a purchase price (the “Change of Control Purchase Price”) equal to 101% of the principal amount thereof plus accrued and unpaid interest, if any, to the date of repurchase, subject to the right of Holders of Securities of such Series on the relevant record date to receive interest due on the relevant interest payment date.

Within 30 days following the date upon which the Issuer becomes aware that a Change of Control Triggering Event has occurred, or at the Issuer’s option, prior to any Change of Control but after the public announcement of the pending Change of Control, the Issuer shall be required to send, by first class mail or electronic delivery, a notice to each Holder of such Securities, with a copy to the Trustee, which notice shall govern the terms of the Change of Control Offer. Such notice shall state, among other things, the purchase date, which must be no earlier than 30 days nor later than 60 days from the date such notice is mailed or delivered, other than as may be required by law (the “Change of Control Payment Date”). The notice, if mailed or delivered prior to the date of consummation of the Change of Control, shall state that the Change of Control Offer is conditioned on the Change of Control Triggering Event occurring on or prior to the Change of Control Payment Date. The Issuer shall not be required to make a Change of Control Offer upon the occurrence of a Change of Control Triggering Event if a third party makes such an offer in the manner, at the times and otherwise in compliance with the requirements for such an offer made by the Issuer and such third party purchases all Securities of the applicable Series properly tendered and not withdrawn under its offer.

The Issuer shall be required to comply with the requirements of Rule 14e-1 under the Exchange Act, and any other securities laws and regulations thereunder to the extent those laws and regulations are applicable in connection with the repurchase of the applicable Series of the Securities as a result of a Change of Control Triggering Event. To the extent that the provisions of any securities laws or regulations conflict with this Section 3.2 and the applicable Series of the Securities, the Issuer shall be required to comply with those securities laws and regulations and shall not be deemed to have breached its obligations under this Section 3.2 and such Securities by virtue of any such compliance.

On each Change of Control Payment Date, the Issuer shall, to the extent lawful:

ARTICLE FOUR

LIMITATION ON LIENS

Section 4.1. Limitation on Liens.

The Issuer shall not, and shall not permit any of its Subsidiaries to, create or suffer to exist any Lien on or with respect to any of the Issuer’s properties, whether now owned or hereafter acquired, to secure any Debt of the Issuer, any direct or indirect Subsidiary of the Issuer or any other person without securing the Securities equally and ratably with such Debt to which such Liens relate for so long as such Debt shall be so secured, other than:

(a) Permitted Liens;

(b) purchase money Liens upon or in any real property or equipment acquired or held by the Issuer or any Subsidiary of the Issuer in the ordinary course of business to secure the purchase price of such property or equipment or to secure Debt incurred solely for the purpose of financing the acquisition of such property or equipment, or Liens existing on such property or equipment at the time of its acquisition (other than any such Liens created in contemplation of such acquisition that were not incurred to finance the acquisition of such property) or extensions, renewals or replacements of any of the foregoing for the same or a lesser amount, provided, however, that no such Lien shall extend to or cover any properties of any character other than the real property or equipment being acquired and fixed improvements thereon or accessions thereto, and no such extension, renewal or replacement shall extend to or cover any properties not theretofore subject to the Lien being extended, renewed or replaced;

(c) Liens existing on August 11, 2025;

(d) Liens on property of a person existing at the time such person is merged into, consolidated with, or acquired by the Issuer or any Subsidiary of the Issuer or becomes a Subsidiary of the Issuer; provided that such Liens were not created in contemplation of such merger, consolidation or acquisition and do not extend to any assets other than those of the person so merged into or consolidated with the Issuer or such Subsidiary or acquired by the Issuer or such Subsidiary; (e) Liens granted by Subsidiaries of the Issuer to secure Debt owed to the Issuer or a wholly owned Subsidiary of the Issuer;

(f) Liens arising out of a judgment, decree or order of court being contested in good faith by appropriate proceedings, provided that adequate reserves with respect thereto are maintained on the books of the Issuer or the books of its Subsidiaries, as the case may be, in conformity with GAAP;

(g) Debt of a person existing at the time such person is merged into or consolidated with the Issuer or becomes a Subsidiary of the Issuer provided that such Debt was not created in contemplation of such merger, consolidation or acquisition;

(h) Liens to secure any extension, renewal, refinancing or refunding (or successive extensions, renewals, refinancings or refundings), in whole or in part, of any Debt secured by Liens referred to above or Liens created in connection with any amendment, consent or waiver relating to such Debt, so long as such Lien does not extend to any other property, the amount of Debt secured is not increased (other than by the amount equal to any costs and expenses incurred in connection with any extension, renewal, refinancing or refunding) and the Debt so secured does not exceed the fair market value (as determined by the Issuer’s Board of Directors in good faith) of the assets subject to such Liens at the time of such extension, renewal, refinancing or refunding, or such amendment, consent or waiver, as the case may be;

(i) any assignment of accounts receivable (1) by and among the Issuer and its Subsidiaries or (2) pursuant to non-recourse factoring or similar arrangements or otherwise in an aggregate amount not to exceed in any fiscal year the greater of $1,000,000,000 (measured as the face value of such accounts receivable at the time of assignment) and 10.0% of the consolidated accounts receivable of the Issuer and its Subsidiaries as reflected in the consolidated balance sheet of the Issuer as of the end of the fiscal year of the Issuer most recently ended prior to such assignment for which financial statements are available; and

(j) (1) Liens otherwise prohibited by this covenant, securing Debt or other obligations in an aggregate amount at any time outstanding plus (2) the aggregate face value at the time of assignment of such accounts receivable assigned, the assignment of which is not otherwise permitted by the foregoing exceptions, in an aggregate amount not to exceed 20% of Consolidated Net Worth of the Issuer and its Subsidiaries as set forth in the Issuer’s most recently available financial statements.

ARTICLE FIVE

LIABILITY OF TRUSTEE

Section 5.1 Trustee Not Responsible for Recitals.

The Trustee shall not be responsible in any matter whatsoever for or in respect of the validity or sufficiency of this Fifth Supplemental Indenture or for or in respect of the recitals contained herein, all of which are made solely by the Issuer or for or with respect to (i) the proper authorization by the Issuer by action or otherwise, (ii) the due execution hereof by the Issuer or (iii) the consequences of any amendment herein provided for, and the Trustee makes no representation with respect to any such matters.

ARTICLE SIX

MISCELLANEOUS

Section 6.1. Ratification and Effect.

Except as hereby expressly amended, the Indenture is in all respects ratified and confirmed and all the terms, provisions and conditions thereof shall be and remain in full force and effect.

Upon and after the execution of this Fifth Supplemental Indenture, each reference in the Indenture to “this Indenture,” “hereunder,” “hereof” or words of like import referring to the Indenture shall mean and be a reference to the Indenture as modified hereby.

Section 6.2 Governing Law.

THIS FIFTH SUPPLEMENTAL INDENTURE AND THE SECURITIES SHALL BE GOVERNED BY THE LAWS OF THE STATE OF NEW YORK APPLICABLE TO AGREEMENTS MADE AND TO BE PERFORMED IN SUCH STATE, WITHOUT REGARD TO THE CONFLICT OF LAWS PROVISIONS THEREOF.

Section 6.3 Counterpart Originals.

This Fifth Supplemental Indenture may be executed in any number of counterparts and by the parties hereto in separate counterparts, each of which when so executed shall be deemed to be an original and all of which taken together shall constitute one and the same agreement.

Section 6.4 Effect of Headings. 

The headings of the Articles and Sections of this Fifth Supplemental Indenture have been inserted for convenience of reference only, are not to be considered a part hereof, and shall in no way modify or restrict any of the terms or provisions hereof.

Section 6.5. Severability.

In case any provision in this Fifth Supplemental Indenture or in the Securities of any Series shall be invalid, illegal or unenforceable, the validity, legality and enforceability of the remaining provisions shall not in any way be affected or impaired thereby.

Section 6.6. Modification, Amendment and Waiver.

The provisions of this Fifth Supplemental Indenture may not be amended, supplemented, modified or waived except by an execution of a Supplemental Indenture executed by the Issuer and the Trustee. Any such amendment shall comply with Article IX of the Indenture. Until an amendment, waiver or other action by Holders becomes effective, a consent thereto by a Holder of the applicable Series of the Security hereunder is a continuing consent by the Holder and every subsequent Holder of that Security or portion of the Security that evidences the same obligation as the consenting Holder’s Security, even if notation of the consent, waiver or action is not made on such Security. However, any such Holder or subsequent Holder may revoke the consent, waiver or action as to such Holder’s Security or portion of such Security if the Trustee receives the notice of revocation before the date the amendment, waiver or action becomes effective. After an amendment, waiver or action becomes effective, it shall bind every Holder.

Section 6.7. Ratification of Indenture; Supplemental Indenture Part of Indenture.

This Fifth Supplemental Indenture shall form a part of the Indenture for all purposes, and every Holder of Securities heretofore or hereafter authenticated and delivered shall be bound hereby.

Section 6.8. Trust Indenture Acts Controls.

If any provision of this Fifth Supplemental Indenture limits, qualifies or conflicts with any provision of the Trust Indenture Act of 1939, as amended (the “TIA”), that is required under the TIA to be part of and govern any provision of this Fifth Supplemental Indenture, the provision of the TIA shall control. If any provision of this Fifth Supplemental Indenture modifies or excludes any provisions of the TIA that may be so modified or excluded, the provisions of the TIA shall be deemed to apply to the Indenture as so modified or to be excluded by this Fifth Supplemental Indenture, as the case may be.

Section 6.9. Consent to Jurisdiction; Waiver of Jury Trial.

The Issuer agrees that any legal suit, action or proceeding brought by any party to enforce any rights under or with respect to this Fifth Supplemental Indenture, any Security or any other document or the transactions contemplated hereby or thereby may be instituted in any state or federal court in The Borough of Manhattan, The City of New York, State of New York, United States of America, irrevocably waives to the fullest extent permitted by law any objection which it may now or hereafter have to the laying of venue of any such suit, action or proceeding, irrevocably waives to the fullest extent permitted by law any claim that and agrees not to claim or plead in any court that any such action, suit or proceeding brought in such court has been brought in an inconvenient forum and irrevocably submits to the non-exclusive jurisdiction of any such court in any such suit, action or proceeding or for recognition and enforcement of any judgment in respect thereof.

To the extent that the Issuer or any of its Subsidiaries has or hereafter may acquire any immunity from jurisdiction of any court (including any court in the United States, the State of New York or other jurisdiction in which the Issuer or any successor thereof may be organized or any political subdivisions thereof) or from any legal process (whether through service of notice, attachment prior to judgment, attachment in aid of execution, execution or otherwise) with respect to itself or its property or assets, this Fifth Supplemental Indenture, the applicable Series of the Securities, the transactions contemplated hereby or thereby or any other documents or actions to enforce judgments in respect of any thereof, then the Issuer hereby irrevocably waives, and will cause its Subsidiaries to waive, such immunity, and any defense based on such immunity, in respect of its obligations under the above-referenced documents and the transactions contemplated thereby, to the extent permitted by law.

THE PARTIES HERETO HEREBY WAIVE TRIAL BY JURY IN ANY ACTION BROUGHT ON OR WITH RESPECT TO THIS AGREEMENT, ANY SERIES OF THE SECURITIES, THE TRANSACTIONS CONTEMPLATED HEREBY AND THEREBY OR ANY OTHER DOCUMENT EXECUTED IN CONNECTION HEREWITH OR THEREWITH.

[Signatures pages follow]

IN WITNESS WHEREOF, the parties hereto have caused this Fifth Supplemental Indenture to be duly executed as of the day and year first above written.

OMNICOM GROUP INC.

[Signature Page to Fifth Supplemental Indenture]

DEUTSCHE BANK TRUST COMPANY AMERICAS, as Trustee

[Signature Page to Fifth Supplemental Indenture]

Exhibit A

(Face of Note)

[Insert the Global Note Legend and Restricted Note Legend, as applicable, pursuant to the provisions of the Fifth Supplemental Indenture]

4.650% Senior Notes due 2028

ISIN: [___]

CUSIP: [___]

$[___]

No. [144A][Reg S] – [1]

OMNICOM GROUP INC., a New York corporation (the “Issuer,” which term includes any successor person under the Indenture hereinafter referred to), for value received, hereby promises to pay to CEDE & CO., or registered assigns, the principal sum of $[___] on October 1, 2028 and to pay interest thereon from the last interest payment date on which interest was paid or, if no interest has been paid, from October 1, 2025 semi-annually on April 1 and October 1 in each year, commencing April 1, 2026, at the rate of 4.650% per annum, set forth below. The interest so payable, and punctually paid or duly provided for, on any interest payment date shall, as provided in such Indenture, be paid to the person in whose name this Security (or one or more predecessor securities) is registered at the close of business on the regular record date for such interest, which shall be March 15 and September 15 (whether or not a Business Day), as the case may be, next preceding such interest payment date. Any such interest not so punctually paid or duly provided for shall forthwith cease to be payable to the Holder on such regular record date and may either be paid to the person in whose name this Security (or one or more predecessor securities) is registered at the close of business on a special record date for the payment of such defaulted interest to be fixed by the Trustee, notice whereof shall be given to Holders of Securities of this Series not less than 10 days prior to such special record date, or be paid at any time in any other lawful manner not inconsistent with the requirements of any securities exchange on which the Securities of this Series may be listed, and upon such notice as may be required by such exchange, all as more fully provided in said Indenture).

Payment of the principal of (and premium, if any) and interest on this Security will be made at the office or agency of the Issuer maintained for that purpose in The City of New York, New York, in accordance with the terms of the Indenture referred to on the reverse hereof in such coin or currency of the United States of America as at the time of payment is legal tender for payment of public and private debts; provided, however, that at the option of the Issuer payment of interest may be made by check mailed to the address of the person entitled thereto as such address shall appear in the Security register.

Reference is hereby made to the further provisions of this Security set forth on the reverse hereof, which further provisions shall for all purposes have the same effect as if set forth at this place.

This Security shall be deemed to be a contract made under the laws of the State of New York, and for all purposes shall be construed in accordance with and governed by the laws of said state.

Unless the certificate of authentication hereon has been executed by the Trustee referred to on the reverse hereof by manual signature, this Security shall not be entitled to any benefit under the Indenture or be valid or obligatory for any purpose.

IN WITNESS WHEREOF, the Issuer has caused this instrument to be duly executed.

This is one of the Securities of the Series designated therein referred to in the within-mentioned Indenture.

Reverse of Security

OMNICOM GROUP INC.

4.650% Senior Notes due 2028

This Security is one of a duly authorized issue of securities of the Issuer, designated as its 4.650% Senior Notes due 2028 (herein called the “Securities”), issued and to be issued in one or more Series under an Indenture, dated as of February 21, 2020 (the “Base Indenture”), between the Issuer and Deutsche Bank Trust Company Americas, as Trustee (herein called the “Trustee,” which term includes any successor trustee under the Indenture), as supplemented by the Fifth Supplemental Indenture dated as of December 2, 2025, between the Issuer and the Trustee (the “Fifth Supplemental Indenture” and, together with the Base Indenture, the “Indenture”), to which Indenture and all indentures supplemental thereto reference is hereby made for a statement of the respective rights, limitations of rights, duties and immunities thereunder of the Issuer, the Trustee and the Holders of the Securities and of the terms upon which the Securities are, and are to be, authenticated and delivered. This Security is one of the Series designated on the face hereof, initially limited in aggregate principal amount to $[___]. Capitalized terms used in this Security and not defined herein have the meaning ascribed thereto in the Indenture.

Deutsche Bank Trust Company Americas, the Trustee under the Indenture, has been appointed by the Issuer as Paying Agent, Registrar and custodian with regard to the Securities.

In case an Event of Default shall have occurred and be continuing, the principal of and accrued interest on all Securities may be declared, and upon said declaration, shall become due and payable, in the manner, with the effect and subject to the conditions provided for in the Indenture.

Prior to July 1, 2028 (the “Par Call Date”), the Issuer may redeem the Securities at its option, in whole or in part, at any time and from time to time, at a redemption price (expressed as a percentage of principal amount and rounded to three decimal places) equal to the greater of:

On or after the Par Call Date, the Issuer may redeem the Securities, in whole or in part, at any time and from time to time, at a redemption price equal to 100% of the principal amount of the Securities being redeemed plus accrued and unpaid interest thereon to the redemption date.

“Treasury Rate” means, with respect to any redemption date, the yield determined by the Issuer after 4:15 p.m., New York City time (or after such time as yields on U.S. government securities are posted daily by the Board of Governors of the Federal Reserve System), on the third Business Day preceding the redemption date based upon the yield or yields for the most recent day that appear after such time on such day in the most recent statistical release published by the Board of Governors of the Federal Reserve System designated as “Selected Interest Rates (Daily) — H.15” (or any successor designation or publication) (“H.15”) under the caption “U.S. government securities — Treasury constant maturities — Nominal” (or any successor caption or heading) (“H.15 TCM”). In determining the Treasury Rate, the Issuer shall select, as applicable: (1) the yield for the Treasury constant maturity on H.15 exactly equal to the period from the redemption date to the Par Call Date (the “Remaining Life”); or (2) if there is no such Treasury constant maturity on H.15 exactly equal to the Remaining Life, the two yields — one yield corresponding to the Treasury constant maturity on H.15 immediately shorter than and one yield corresponding to the Treasury constant maturity on H.15 immediately longer than the Remaining Life — and shall interpolate to the Par Call Date on a straight-line basis (using the actual number of days) using such yields and rounding the result to three decimal places; or (3) if there is no such Treasury constant maturity on H.15 shorter than or longer than the Remaining Life, the yield for the single Treasury constant maturity on H.15 closest to the Remaining Life. For purposes of this paragraph, the applicable Treasury constant maturity or maturities on H.15 shall be deemed to have a maturity date equal to the relevant number of months or years, as applicable, of such Treasury constant maturity from the redemption date.

If on the third Business Day preceding the redemption date H.15 TCM is no longer published, the Issuer shall calculate the Treasury Rate based on the rate per annum equal to the semi-annual equivalent yield to maturity at 11:00 a.m., New York City time, on the second Business Day preceding such redemption date of the United States Treasury security maturing on, or with a maturity that is closest to, the Par Call Date, as applicable. If there is no United States Treasury security maturing on the Par Call Date but there are two or more United States Treasury securities with a maturity date equally distant from the Par Call Date, one with a maturity date preceding the Par Call Date and one with a maturity date following the Par Call Date, the Issuer shall select the United States Treasury security with a maturity date preceding the Par Call Date. If there are two or more United States Treasury securities maturing on the Par Call Date or two or more United States Treasury securities meeting the criteria of the preceding sentence, the Issuer shall select from among these two or more United States Treasury securities the United States Treasury security that is trading closest to par based upon the average of the bid and asked prices for such United States Treasury securities at 11:00 a.m., New York City time. In determining the Treasury Rate in accordance with the terms of this paragraph, the semi-annual yield to maturity of the applicable United States Treasury security shall be based upon the average of the bid and asked prices (expressed as a percentage of principal amount) at 11:00 a.m., New York City time, of such United States Treasury security, and rounded to three decimal places.

Notice of any redemption will be mailed or electronically delivered (or otherwise transmitted in accordance with the Depository’s procedures) at least 10 days but not more than 60 days before the redemption date to each Holder of Securities to be redeemed at its registered address.

The Issuer’s actions and determinations in determining the redemption price shall be conclusive and binding for all purposes, absent manifest error. The calculation or determination of the redemption price shall be made by the Issuer or on its behalf by such person as the Issuer shall designate. For the avoidance of doubt, the calculation or determination of the redemption price, including the determination of any Treasury Rate, shall not be the obligation or responsibility of the Trustee or Paying Agent.

On and after the redemption date, interest shall cease to accrue on the Securities or any portion of the Securities called for redemption (unless the Issuer defaults in the payment of the redemption price and accrued interest). On or before 10:00 a.m. New York City time on the redemption date, the Issuer shall deposit with a Paying Agent (or the Trustee, if other than the Paying Agent) money sufficient to pay the redemption price of and accrued interest on the Securities to be redeemed on that date. If less than all of the Securities are to be redeemed, the Securities to be redeemed shall be selected by such method as the Trustee deems fair and appropriate, subject to the procedures of the Depository.

In the event of redemption of this Security in part only, a new Security or Securities of this Series and of like tenor for the unredeemed portion hereof shall be issued in the name of the Holder hereof upon the cancellation hereof; provided that in the case of a Global Security, an appropriate book-entry adjustment may be made in lieu of the issuance of a new Security.

The Indenture contains provisions that permit the Issuer to elect either (1) to defease and be discharged from the entire indebtedness of this Security or (2) to be released from its obligations under certain restrictive covenants and Events of Default with respect to this Security, in each case upon payment in full of the Securities and compliance with certain conditions set forth in the Indenture.

Upon the occurrence of a Change of Control Triggering Event with respect to the Securities of this Series, the Issuer shall be required to make an offer to repurchase the Securities of this Series on the terms set forth in Section 3.2 of the Fifth Supplemental Indenture.

If an Event of Default with respect to Securities of this Series shall occur and be continuing, the principal of the Securities of this Series may be declared due and payable in the manner and with the effect provided in the Indenture.

The Indenture permits the amendment thereof and the modification of the rights and obligations of the Issuer and the rights of the Holders of the Securities of each Series to be affected under the Indenture at any time by the Issuer and the Trustee with the consent of the Holders of a majority in principal amount of the Securities at the time outstanding of each Series to be affected, with certain exceptions as therein provided with respect to certain modifications or amendments which may not be made without the consent of each Holder of such Security affected thereby. The Indenture also permits certain amendments and modifications thereto from time to time by the Issuer and the Trustee without the consent of the Holders of any Series of the Securities to be affected thereby for certain specified purposes, including curing ambiguities, defects or inconsistencies and making any such change that does not adversely affect the legal rights of any Holder of such Series of the Securities, as provided therein.

The Indenture contains provisions permitting the Holders of specified percentages in principal amount of the Securities of each Series at the time outstanding, on behalf of the Holders of all Securities of such Series, to waive compliance by the Issuer with certain provisions of the Indenture and certain past defaults under the Indenture and their consequences with respect to such Series. Any such consent or waiver by the Holder of this Security shall be conclusive and binding upon such Holder and upon all future Holders of this Security and of any Security issued upon the registration of transfer hereof or in exchange hereof or in lieu hereof, whether or not notation of such consent or waiver is made upon this Security.

No reference herein to the Indenture and no provision of this Security or of the Indenture shall alter or impair the obligation of the Issuer, which is absolute and unconditional, to pay the principal of and any premium and Interest on this Security at the times, place and rate, and in the coin or currency, herein prescribed.

As provided in the Indenture and subject to certain limitations therein set forth, the transfer of this Security is registrable in the security register, upon surrender of this Security for registration of transfer at the office or agency of the Issuer in any place where the principal of and any premium and interest on this Security are payable, duly endorsed by, or accompanied by a written instrument of transfer in form satisfactory to the Issuer and the Registrar duly executed by, the Holder hereof or its attorney duly authorized in writing, and thereupon one or more new Securities of this Series and of like tenor, of authorized denominations and for the same aggregate principal amount, shall be issued to the designated transferee or transferees.

The Securities of this Series are issuable only in registered form without coupons in denominations of $2,000 and integral multiples of $1,000 in excess thereof. As provided in the Indenture and subject to certain limitations therein set forth, Securities of this Series are exchangeable for a like aggregate principal amount of Securities of this Series and of like tenor of a different authorized denomination, as requested by the Holder surrendering the same.

No service charge shall be made for any such registration of transfer or exchange, but the Issuer may require payment of a sum sufficient to cover any tax or other governmental charge payable in connection therewith.

Prior to due presentment of this Security for registration of transfer, the Issuer, the Trustee and any agent of the Issuer or the Trustee may treat the person in whose name this Security is registered as the owner hereof for all purposes, whether or not this Security is overdue, and none of the Issuer, the Trustee or any such agent shall be affected by notice to the contrary.

No recourse shall be had for the payment of the principal of (and premium, if any) or interest on this Security, or for any claim based hereon, or otherwise in respect hereof, or based on or in respect of the Indenture or any indenture supplemental thereto, against any incorporator, stockholder, officer or director, as such, past, present or future, of the Issuer or of any successor corporation, whether by virtue of any constitution, statute or rule of law, or by the enforcement of any assessment or penalty or otherwise, all such liability being, by the acceptance hereof and as part of the consideration for the issue hereof, expressly waived and released.

All terms used in this Security which are defined in the Indenture shall have the meanings assigned to them in the Indenture.

ASSIGNMENT FORM

To assign this Security, fill in the form below:

(I) or (we) assign and transfer this Security to: __________________

________________________

(Insert assignee’s legal name)

________________________

(Insert assignee’s soc. sec. or tax I.D. no.)

 _______________________

_______________________

_______________________   

(Print or type assignee’s name, address and zip code)

and irrevocably appoint  _______________

to transfer this Security on the books of the Issuer: The agent may substitute another to act for him.

Signatures must be guaranteed by an “eligible guarantor institution” meeting the requirements of the Registrar, which requirements include membership or participation in the Security Transfer Agent Medallion Program (“STAMP”) or such other “signature guarantee program” as may be determined by the Registrar in addition to, or in substitution for, STAMP, all in accordance with the Securities Exchange Act of 1934, as amended.

The undersigned hereby certifies that it is / is not an Affiliate of the Issuer and that, to its knowledge, the proposed transferee is / is not an Affiliate of the Issuer.

In connection with any transfer or exchange of any of the Securities evidenced by this certificate occurring prior to the date that is one year after the later of the date of original issuance of such Securities and the last date, if any, on which such Securities were owned by the Issuer or any Affiliate of the Issuer, the undersigned confirms that such Securities are being:

CHECK ONE BOX BELOW:

(1) ☐ acquired for the undersigned’s own account, without transfer; or

(2) ☐ transferred to the Issuer; or

(3) ☐ transferred to a Person that the undersigned reasonably believes is a “qualified institutional buyer” in compliance with Rule 144A under the Securities Act of 1933, as amended (the “Securities Act”); or

(4) ☐ transferred in an “offshore transaction” in compliance with Rule 904 of Regulation S under the Securities Act (provided that the transferor has furnished to the Trustee a signed letter containing certain representations and agreements, the form of which letter appears as Exhibit G to the Fifth Supplemental Indenture); or

(5) ☐ transferred pursuant to an exemption from registration provided by Rule 144 under the Securities Act or any other available exemption from the registration requirements of the Securities Act; or

(6) ☐ transferred pursuant to a registration statement which has become effective under the Securities Act.

Unless one of the boxes is checked, the Trustee will refuse to register any of the Securities evidenced by this certificate in the name of any person other than the registered Holder thereof; provided, however, that if box (5) is checked, the Issuer may require, prior to registering any such transfer of the Securities, in its sole discretion, such legal opinions, certifications and other information as the Issuer may reasonably request to confirm that such transfer is being made pursuant to an exemption from, or in a transaction not subject to, the registration requirements of the Securities Act, such as the exemption provided by Rule 144 under such Act.

TO BE COMPLETED BY PURCHASER IF BOX (1) OR (3) ABOVE IS CHECKED.

The undersigned represents and warrants that it is purchasing this Security for its own account or an account with respect to which it exercises sole investment discretion and that it and any such account is a “qualified institutional buyer” within the meaning of Rule 144A under the Securities Act, and is aware that the sale to it is being made in reliance on Rule 144A and acknowledges that it has received such information regarding the Issuer as the undersigned has requested pursuant to Rule 144A or has determined not to request such information and that it is aware that the transferor is relying upon the undersigned’s foregoing representations in order to claim the exemption from registration provided by Rule 144A.

____________________________

Dated:

Exhibit B

(Face of Note)

[Insert the Global Note Legend and Restricted Note Legend, as applicable, pursuant to the provisions of the Fifth Supplemental Indenture]

4.750% Senior Notes due 2030

ISIN: [___]

CUSIP: [___]

$[___]

No. [144A][Reg S] – [1]

OMNICOM GROUP INC., a New York corporation (the “Issuer,” which term includes any successor person under the Indenture hereinafter referred to), for value received, hereby promises to pay to CEDE & CO., or registered assigns, the principal sum of $[___] on March 30, 2030 and to pay interest thereon from the last interest payment date on which interest was paid or, if no interest has been paid, from September 30, 2025 semi-annually on March 30 and September 30 in each year, commencing March 30, 2026, at the rate of 4.750% per annum, set forth below. The interest so payable, and punctually paid or duly provided for, on any interest payment date shall, as provided in such Indenture, be paid to the person in whose name this Security (or one or more predecessor securities) is registered at the close of business on the regular record date for such interest, which shall be March 15 and September 15 (whether or not a Business Day), as the case may be, next preceding such interest payment date. Any such interest not so punctually paid or duly provided for shall forthwith cease to be payable to the Holder on such regular record date and may either be paid to the person in whose name this Security (or one or more predecessor securities) is registered at the close of business on a special record date for the payment of such defaulted interest to be fixed by the Trustee, notice whereof shall be given to Holders of Securities of this Series not less than 10 days prior to such special record date, or be paid at any time in any other lawful manner not inconsistent with the requirements of any securities exchange on which the Securities of this Series may be listed, and upon such notice as may be required by such exchange, all as more fully provided in said Indenture).

Payment of the principal of (and premium, if any) and interest on this Security will be made at the office or agency of the Issuer maintained for that purpose in The City of New York, New York, in accordance with the terms of the Indenture referred to on the reverse hereof in such coin or currency of the United States of America as at the time of payment is legal tender for payment of public and private debts; provided, however, that at the option of the Issuer payment of interest may be made by check mailed to the address of the person entitled thereto as such address shall appear in the Security register.

Reference is hereby made to the further provisions of this Security set forth on the reverse hereof, which further provisions shall for all purposes have the same effect as if set forth at this place.

This Security shall be deemed to be a contract made under the laws of the State of New York, and for all purposes shall be construed in accordance with and governed by the laws of said state.

Unless the certificate of authentication hereon has been executed by the Trustee referred to on the reverse hereof by manual signature, this Security shall not be entitled to any benefit under the Indenture or be valid or obligatory for any purpose.

IN WITNESS WHEREOF, the Issuer has caused this instrument to be duly executed.

This is one of the Securities of the Series designated therein referred to in the within-mentioned Indenture.

Reverse of Security

OMNICOM GROUP INC.

4.750% Senior Notes due 2030

This Security is one of a duly authorized issue of securities of the Issuer, designated as its 4.750% Senior Notes due 2030 (herein called the “Securities”), issued and to be issued in one or more Series under an Indenture, dated as of February 21, 2020 (the “Base Indenture”), between the Issuer and Deutsche Bank Trust Company Americas, as Trustee (herein called the “Trustee,” which term includes any successor trustee under the Indenture), as supplemented by the Fifth Supplemental Indenture dated as of December 2, 2025, between the Issuer and the Trustee (the “Fifth Supplemental Indenture” and, together with the Base Indenture, the “Indenture”), to which Indenture and all indentures supplemental thereto reference is hereby made for a statement of the respective rights, limitations of rights, duties and immunities thereunder of the Issuer, the Trustee and the Holders of the Securities and of the terms upon which the Securities are, and are to be, authenticated and delivered. This Security is one of the Series designated on the face hereof, initially limited in aggregate principal amount to $[___]. Capitalized terms used in this Security and not defined herein have the meaning ascribed thereto in the Indenture.

Deutsche Bank Trust Company Americas, the Trustee under the Indenture, has been appointed by the Issuer as Paying Agent, Registrar and custodian with regard to the Securities.

In case an Event of Default shall have occurred and be continuing, the principal of and accrued interest on all Securities may be declared, and upon said declaration, shall become due and payable, in the manner, with the effect and subject to the conditions provided for in the Indenture.

Prior to December 30, 2029 (the “Par Call Date”), the Issuer may redeem the Securities at its option, in whole or in part, at any time and from time to time, at a redemption price (expressed as a percentage of principal amount and rounded to three decimal places) equal to the greater of:

On or after the Par Call Date, the Issuer may redeem the Securities, in whole or in part, at any time and from time to time, at a redemption price equal to 100% of the principal amount of the Securities being redeemed plus accrued and unpaid interest thereon to the redemption date.

“Treasury Rate” means, with respect to any redemption date, the yield determined by the Issuer after 4:15 p.m., New York City time (or after such time as yields on U.S. government securities are posted daily by the Board of Governors of the Federal Reserve System), on the third Business Day preceding the redemption date based upon the yield or yields for the most recent day that appear after such time on such day in the most recent statistical release published by the Board of Governors of the Federal Reserve System designated as “Selected Interest Rates (Daily) — H.15” (or any successor designation or publication) (“H.15”) under the caption “U.S. government securities — Treasury constant maturities — Nominal” (or any successor caption or heading) (“H.15 TCM”). In determining the Treasury Rate, the Issuer shall select, as applicable: (1) the yield for the Treasury constant maturity on H.15 exactly equal to the period from the redemption date to the Par Call Date (the “Remaining Life”); or (2) if there is no such Treasury constant maturity on H.15 exactly equal to the Remaining Life, the two yields — one yield corresponding to the Treasury constant maturity on H.15 immediately shorter than and one yield corresponding to the Treasury constant maturity on H.15 immediately longer than the Remaining Life — and shall interpolate to the Par Call Date on a straight-line basis (using the actual number of days) using such yields and rounding the result to three decimal places; or (3) if there is no such Treasury constant maturity on H.15 shorter than or longer than the Remaining Life, the yield for the single Treasury constant maturity on H.15 closest to the Remaining Life. For purposes of this paragraph, the applicable Treasury constant maturity or maturities on H.15 shall be deemed to have a maturity date equal to the relevant number of months or years, as applicable, of such Treasury constant maturity from the redemption date.

If on the third Business Day preceding the redemption date H.15 TCM is no longer published, the Issuer shall calculate the Treasury Rate based on the rate per annum equal to the semi-annual equivalent yield to maturity at 11:00 a.m., New York City time, on the second Business Day preceding such redemption date of the United States Treasury security maturing on, or with a maturity that is closest to, the Par Call Date, as applicable. If there is no United States Treasury security maturing on the Par Call Date but there are two or more United States Treasury securities with a maturity date equally distant from the Par Call Date, one with a maturity date preceding the Par Call Date and one with a maturity date following the Par Call Date, the Issuer shall select the United States Treasury security with a maturity date preceding the Par Call Date. If there are two or more United States Treasury securities maturing on the Par Call Date or two or more United States Treasury securities meeting the criteria of the preceding sentence, the Issuer shall select from among these two or more United States Treasury securities the United States Treasury security that is trading closest to par based upon the average of the bid and asked prices for such United States Treasury securities at 11:00 a.m., New York City time. In determining the Treasury Rate in accordance with the terms of this paragraph, the semi-annual yield to maturity of the applicable United States Treasury security shall be based upon the average of the bid and asked prices (expressed as a percentage of principal amount) at 11:00 a.m., New York City time, of such United States Treasury security, and rounded to three decimal places.

Notice of any redemption will be mailed or electronically delivered (or otherwise transmitted in accordance with the Depository’s procedures) at least 10 days but not more than 60 days before the redemption date to each Holder of Securities to be redeemed at its registered address.

The Issuer’s actions and determinations in determining the redemption price shall be conclusive and binding for all purposes, absent manifest error. The calculation or determination of the redemption price shall be made by the Issuer or on its behalf by such person as the Issuer shall designate. For the avoidance of doubt, the calculation or determination of the redemption price, including the determination of any Treasury Rate, shall not be the obligation or responsibility of the Trustee or Paying Agent.

On and after the redemption date, interest shall cease to accrue on the Securities or any portion of the Securities called for redemption (unless the Issuer defaults in the payment of the redemption price and accrued interest). On or before 10:00 a.m. New York City time on the redemption date, the Issuer shall deposit with a Paying Agent (or the Trustee, if other than the Paying Agent) money sufficient to pay the redemption price of and accrued interest on the Securities to be redeemed on that date. If less than all of the Securities are to be redeemed, the Securities to be redeemed shall be selected by such method as the Trustee deems fair and appropriate, subject to the procedures of the Depository.

In the event of redemption of this Security in part only, a new Security or Securities of this Series and of like tenor for the unredeemed portion hereof shall be issued in the name of the Holder hereof upon the cancellation hereof; provided that in the case of a Global Security, an appropriate book-entry adjustment may be made in lieu of the issuance of a new Security.

The Indenture contains provisions that permit the Issuer to elect either (1) to defease and be discharged from the entire indebtedness of this Security or (2) to be released from its obligations under certain restrictive covenants and Events of Default with respect to this Security, in each case upon payment in full of the Securities and compliance with certain conditions set forth in the Indenture.

Upon the occurrence of a Change of Control Triggering Event with respect to the Securities of this Series, the Issuer shall be required to make an offer to repurchase the Securities of this Series on the terms set forth in Section 3.2 of the Fifth Supplemental Indenture.

If an Event of Default with respect to Securities of this Series shall occur and be continuing, the principal of the Securities of this Series may be declared due and payable in the manner and with the effect provided in the Indenture.

The Indenture permits the amendment thereof and the modification of the rights and obligations of the Issuer and the rights of the Holders of the Securities of each Series to be affected under the Indenture at any time by the Issuer and the Trustee with the consent of the Holders of a majority in principal amount of the Securities at the time outstanding of each Series to be affected, with certain exceptions as therein provided with respect to certain modifications or amendments which may not be made without the consent of each Holder of such Security affected thereby. The Indenture also permits certain amendments and modifications thereto from time to time by the Issuer and the Trustee without the consent of the Holders of any Series of the Securities to be affected thereby for certain specified purposes, including curing ambiguities, defects or inconsistencies and making any such change that does not adversely affect the legal rights of any Holder of such Series of the Securities, as provided therein.

The Indenture contains provisions permitting the Holders of specified percentages in principal amount of the Securities of each Series at the time outstanding, on behalf of the Holders of all Securities of such Series, to waive compliance by the Issuer with certain provisions of the Indenture and certain past defaults under the Indenture and their consequences with respect to such Series. Any such consent or waiver by the Holder of this Security shall be conclusive and binding upon such Holder and upon all future Holders of this Security and of any Security issued upon the registration of transfer hereof or in exchange hereof or in lieu hereof, whether or not notation of such consent or waiver is made upon this Security.

No reference herein to the Indenture and no provision of this Security or of the Indenture shall alter or impair the obligation of the Issuer, which is absolute and unconditional, to pay the principal of and any premium and Interest on this Security at the times, place and rate, and in the coin or currency, herein prescribed.

As provided in the Indenture and subject to certain limitations therein set forth, the transfer of this Security is registrable in the security register, upon surrender of this Security for registration of transfer at the office or agency of the Issuer in any place where the principal of and any premium and interest on this Security are payable, duly endorsed by, or accompanied by a written instrument of transfer in form satisfactory to the Issuer and the Registrar duly executed by, the Holder hereof or its attorney duly authorized in writing, and thereupon one or more new Securities of this Series and of like tenor, of authorized denominations and for the same aggregate principal amount, shall be issued to the designated transferee or transferees.

The Securities of this Series are issuable only in registered form without coupons in denominations of $2,000 and integral multiples of $1,000 in excess thereof. As provided in the Indenture and subject to certain limitations therein set forth, Securities of this Series are exchangeable for a like aggregate principal amount of Securities of this Series and of like tenor of a different authorized denomination, as requested by the Holder surrendering the same.

No service charge shall be made for any such registration of transfer or exchange, but the Issuer may require payment of a sum sufficient to cover any tax or other governmental charge payable in connection therewith.

Prior to due presentment of this Security for registration of transfer, the Issuer, the Trustee and any agent of the Issuer or the Trustee may treat the person in whose name this Security is registered as the owner hereof for all purposes, whether or not this Security is overdue, and none of the Issuer, the Trustee or any such agent shall be affected by notice to the contrary.

No recourse shall be had for the payment of the principal of (and premium, if any) or interest on this Security, or for any claim based hereon, or otherwise in respect hereof, or based on or in respect of the Indenture or any indenture supplemental thereto, against any incorporator, stockholder, officer or director, as such, past, present or future, of the Issuer or of any successor corporation, whether by virtue of any constitution, statute or rule of law, or by the enforcement of any assessment or penalty or otherwise, all such liability being, by the acceptance hereof and as part of the consideration for the issue hereof, expressly waived and released.

All terms used in this Security which are defined in the Indenture shall have the meanings assigned to them in the Indenture.

ASSIGNMENT FORM

To assign this Security, fill in the form below:

(I) or (we) assign and transfer this Security to: __________________

________________________

(Insert assignee’s legal name)

________________________

(Insert assignee’s soc. sec. or tax I.D. no.)

 _______________________

_______________________

_______________________   

(Print or type assignee’s name, address and zip code)

and irrevocably appoint  _______________

to transfer this Security on the books of the Issuer: The agent may substitute another to act for him.

Signatures must be guaranteed by an “eligible guarantor institution” meeting the requirements of the Registrar, which requirements include membership or participation in the Security Transfer Agent Medallion Program (“STAMP”) or such other “signature guarantee program” as may be determined by the Registrar in addition to, or in substitution for, STAMP, all in accordance with the Securities Exchange Act of 1934, as amended.

The undersigned hereby certifies that it  is /  is not an Affiliate of the Issuer and that, to its knowledge, the proposed transferee  is /  is not an Affiliate of the Issuer.

In connection with any transfer or exchange of any of the Securities evidenced by this certificate occurring prior to the date that is one year after the later of the date of original issuance of such Securities and the last date, if any, on which such Securities were owned by the Issuer or any Affiliate of the Issuer, the undersigned confirms that such Securities are being:

CHECK ONE BOX BELOW:

(1) ☐ acquired for the undersigned’s own account, without transfer; or

(2) ☐ transferred to the Issuer; or

(3) ☐ transferred to a Person that the undersigned reasonably believes is a “qualified institutional buyer” in compliance with Rule 144A under the Securities Act of 1933, as amended (the “Securities Act”); or

(4) ☐ transferred in an “offshore transaction” in compliance with Rule 904 of Regulation S under the Securities Act (provided that the transferor has furnished to the Trustee a signed letter containing certain representations and agreements, the form of which letter appears as Exhibit G to the Fifth Supplemental Indenture); or

(5) ☐ transferred pursuant to an exemption from registration provided by Rule 144 under the Securities Act or any other available exemption from the registration requirements of the Securities Act; or

(6) ☐ transferred pursuant to a registration statement which has become effective under the Securities Act.

Unless one of the boxes is checked, the Trustee will refuse to register any of the Securities evidenced by this certificate in the name of any person other than the registered Holder thereof; provided, however, that if box (5) is checked, the Issuer may require, prior to registering any such transfer of the Securities, in its sole discretion, such legal opinions, certifications and other information as the Issuer may reasonably request to confirm that such transfer is being made pursuant to an exemption from, or in a transaction not subject to, the registration requirements of the Securities Act, such as the exemption provided by Rule 144 under such Act.

* Participant in a recognized Signature Guarantee Medallion Program (or other signature guarantor acceptable to the Trustee).

TO BE COMPLETED BY PURCHASER IF BOX (1) OR (3) ABOVE IS CHECKED.

The undersigned represents and warrants that it is purchasing this Security for its own account or an account with respect to which it exercises sole investment discretion and that it and any such account is a “qualified institutional buyer” within the meaning of Rule 144A under the Securities Act, and is aware that the sale to it is being made in reliance on Rule 144A and acknowledges that it has received such information regarding the Issuer as the undersigned has requested pursuant to Rule 144A or has determined not to request such information and that it is aware that the transferor is relying upon the undersigned’s foregoing representations in order to claim the exemption from registration provided by Rule 144A.

____________________________

Dated:

Exhibit C

(Face of Note)

[Insert the Global Note Legend and Restricted Note Legend, as applicable, pursuant to the provisions of the Fifth Supplemental Indenture]

2.400% Senior Notes due 2031

ISIN: [___]

CUSIP: [___]

$[___]

No. [144A][Reg S] – [1]

OMNICOM GROUP INC., a New York corporation (the “Issuer,” which term includes any successor person under the Indenture hereinafter referred to), for value received, hereby promises to pay to CEDE & CO., or registered assigns, the principal sum of $[___] on March 1, 2031 and to pay interest thereon from the last interest payment date on which interest was paid or, if no interest has been paid, from September 1, 2025 semi-annually on March 1 and September 1 in each year, commencing March 1, 2026, at the rate of 2.400% per annum, set forth below. The interest so payable, and punctually paid or duly provided for, on any interest payment date shall, as provided in such Indenture, be paid to the person in whose name this Security (or one or more predecessor securities) is registered at the close of business on the regular record date for such interest, which shall be February 15 and August 15 (whether or not a Business Day), as the case may be, next preceding such interest payment date. Any such interest not so punctually paid or duly provided for shall forthwith cease to be payable to the Holder on such regular record date and may either be paid to the person in whose name this Security (or one or more predecessor securities) is registered at the close of business on a special record date for the payment of such defaulted interest to be fixed by the Trustee, notice whereof shall be given to Holders of Securities of this Series not less than 10 days prior to such special record date, or be paid at any time in any other lawful manner not inconsistent with the requirements of any securities exchange on which the Securities of this Series may be listed, and upon such notice as may be required by such exchange, all as more fully provided in said Indenture).

Payment of the principal of (and premium, if any) and interest on this Security will be made at the office or agency of the Issuer maintained for that purpose in The City of New York, New York, in accordance with the terms of the Indenture referred to on the reverse hereof in such coin or currency of the United States of America as at the time of payment is legal tender for payment of public and private debts; provided, however, that at the option of the Issuer payment of interest may be made by check mailed to the address of the person entitled thereto as such address shall appear in the Security register.

Reference is hereby made to the further provisions of this Security set forth on the reverse hereof, which further provisions shall for all purposes have the same effect as if set forth at this place.

This Security shall be deemed to be a contract made under the laws of the State of New York, and for all purposes shall be construed in accordance with and governed by the laws of said state.

Unless the certificate of authentication hereon has been executed by the Trustee referred to on the reverse hereof by manual signature, this Security shall not be entitled to any benefit under the Indenture or be valid or obligatory for any purpose.

IN WITNESS WHEREOF, the Issuer has caused this instrument to be duly executed.

This is one of the Securities of the Series designated therein referred to in the within-mentioned Indenture.

Reverse of Security

OMNICOM GROUP INC.

2.400% Senior Notes due 2031

This Security is one of a duly authorized issue of securities of the Issuer, designated as its 2.400% Senior Notes due 2031 (herein called the “Securities”), issued and to be issued in one or more Series under an Indenture, dated as of February 21, 2020 (the “Base Indenture”), between the Issuer and Deutsche Bank Trust Company Americas, as Trustee (herein called the “Trustee,” which term includes any successor trustee under the Indenture), as supplemented by the Fifth Supplemental Indenture dated as of December 2, 2025, between the Issuer and the Trustee (the “Fifth Supplemental Indenture” and, together with the Base Indenture, the “Indenture”), to which Indenture and all indentures supplemental thereto reference is hereby made for a statement of the respective rights, limitations of rights, duties and immunities thereunder of the Issuer, the Trustee and the Holders of the Securities and of the terms upon which the Securities are, and are to be, authenticated and delivered. This Security is one of the Series designated on the face hereof, initially limited in aggregate principal amount to $[___]. Capitalized terms used in this Security and not defined herein have the meaning ascribed thereto in the Indenture.

Deutsche Bank Trust Company Americas, the Trustee under the Indenture, has been appointed by the Issuer as Paying Agent, Registrar and custodian with regard to the Securities.

In case an Event of Default shall have occurred and be continuing, the principal of and accrued interest on all Securities may be declared, and upon said declaration, shall become due and payable, in the manner, with the effect and subject to the conditions provided for in the Indenture.

Prior to December 1, 2030 (the “Par Call Date”), the Issuer may redeem the Securities at its option, in whole or in part, at any time and from time to time, at a redemption price (expressed as a percentage of principal amount and rounded to three decimal places) equal to the greater of:

On or after the Par Call Date, the Issuer may redeem the Securities, in whole or in part, at any time and from time to time, at a redemption price equal to 100% of the principal amount of the Securities being redeemed plus accrued and unpaid interest thereon to the redemption date.

“Treasury Rate” means, with respect to any redemption date, the yield determined by the Issuer after 4:15 p.m., New York City time (or after such time as yields on U.S. government securities are posted daily by the Board of Governors of the Federal Reserve System), on the third Business Day preceding the redemption date based upon the yield or yields for the most recent day that appear after such time on such day in the most recent statistical release published by the Board of Governors of the Federal Reserve System designated as “Selected Interest Rates (Daily) — H.15” (or any successor designation or publication) (“H.15”) under the caption “U.S. government securities — Treasury constant maturities — Nominal” (or any successor caption or heading) (“H.15 TCM”). In determining the Treasury Rate, the Issuer shall select, as applicable: (1) the yield for the Treasury constant maturity on H.15 exactly equal to the period from the redemption date to the Par Call Date (the “Remaining Life”); or (2) if there is no such Treasury constant maturity on H.15 exactly equal to the Remaining Life, the two yields — one yield corresponding to the Treasury constant maturity on H.15 immediately shorter than and one yield corresponding to the Treasury constant maturity on H.15 immediately longer than the Remaining Life — and shall interpolate to the Par Call Date on a straight-line basis (using the actual number of days) using such yields and rounding the result to three decimal places; or (3) if there is no such Treasury constant maturity on H.15 shorter than or longer than the Remaining Life, the yield for the single Treasury constant maturity on H.15 closest to the Remaining Life. For purposes of this paragraph, the applicable Treasury constant maturity or maturities on H.15 shall be deemed to have a maturity date equal to the relevant number of months or years, as applicable, of such Treasury constant maturity from the redemption date.

If on the third Business Day preceding the redemption date H.15 TCM is no longer published, the Issuer shall calculate the Treasury Rate based on the rate per annum equal to the semi-annual equivalent yield to maturity at 11:00 a.m., New York City time, on the second Business Day preceding such redemption date of the United States Treasury security maturing on, or with a maturity that is closest to, the Par Call Date, as applicable. If there is no United States Treasury security maturing on the Par Call Date but there are two or more United States Treasury securities with a maturity date equally distant from the Par Call Date, one with a maturity date preceding the Par Call Date and one with a maturity date following the Par Call Date, the Issuer shall select the United States Treasury security with a maturity date preceding the Par Call Date. If there are two or more United States Treasury securities maturing on the Par Call Date or two or more United States Treasury securities meeting the criteria of the preceding sentence, the Issuer shall select from among these two or more United States Treasury securities the United States Treasury security that is trading closest to par based upon the average of the bid and asked prices for such United States Treasury securities at 11:00 a.m., New York City time. In determining the Treasury Rate in accordance with the terms of this paragraph, the semi-annual yield to maturity of the applicable United States Treasury security shall be based upon the average of the bid and asked prices (expressed as a percentage of principal amount) at 11:00 a.m., New York City time, of such United States Treasury security, and rounded to three decimal places.

Notice of any redemption will be mailed or electronically delivered (or otherwise transmitted in accordance with the Depository’s procedures) at least 10 days but not more than 60 days before the redemption date to each Holder of Securities to be redeemed at its registered address.

The Issuer’s actions and determinations in determining the redemption price shall be conclusive and binding for all purposes, absent manifest error. The calculation or determination of the redemption price shall be made by the Issuer or on its behalf by such person as the Issuer shall designate. For the avoidance of doubt, the calculation or determination of the redemption price, including the determination of any Treasury Rate, shall not be the obligation or responsibility of the Trustee or Paying Agent.

On and after the redemption date, interest shall cease to accrue on the Securities or any portion of the Securities called for redemption (unless the Issuer defaults in the payment of the redemption price and accrued interest). On or before 10:00 a.m. New York City time on the redemption date, the Issuer shall deposit with a Paying Agent (or the Trustee, if other than the Paying Agent) money sufficient to pay the redemption price of and accrued interest on the Securities to be redeemed on that date. If less than all of the Securities are to be redeemed, the Securities to be redeemed shall be selected by such method as the Trustee deems fair and appropriate, subject to the procedures of the Depository.

In the event of redemption of this Security in part only, a new Security or Securities of this Series and of like tenor for the unredeemed portion hereof shall be issued in the name of the Holder hereof upon the cancellation hereof; provided that in the case of a Global Security, an appropriate book-entry adjustment may be made in lieu of the issuance of a new Security.

The Indenture contains provisions that permit the Issuer to elect either (1) to defease and be discharged from the entire indebtedness of this Security or (2) to be released from its obligations under certain restrictive covenants and Events of Default with respect to this Security, in each case upon payment in full of the Securities and compliance with certain conditions set forth in the Indenture.

Upon the occurrence of a Change of Control Triggering Event with respect to the Securities of this Series, the Issuer shall be required to make an offer to repurchase the Securities of this Series on the terms set forth in Section 3.2 of the Fifth Supplemental Indenture.

If an Event of Default with respect to Securities of this Series shall occur and be continuing, the principal of the Securities of this Series may be declared due and payable in the manner and with the effect provided in the Indenture.

The Indenture permits the amendment thereof and the modification of the rights and obligations of the Issuer and the rights of the Holders of the Securities of each Series to be affected under the Indenture at any time by the Issuer and the Trustee with the consent of the Holders of a majority in principal amount of the Securities at the time outstanding of each Series to be affected, with certain exceptions as therein provided with respect to certain modifications or amendments which may not be made without the consent of each Holder of such Security affected thereby. The Indenture also permits certain amendments and modifications thereto from time to time by the Issuer and the Trustee without the consent of the Holders of any Series of the Securities to be affected thereby for certain specified purposes, including curing ambiguities, defects or inconsistencies and making any such change that does not adversely affect the legal rights of any Holder of such Series of the Securities, as provided therein.

The Indenture contains provisions permitting the Holders of specified percentages in principal amount of the Securities of each Series at the time outstanding, on behalf of the Holders of all Securities of such Series, to waive compliance by the Issuer with certain provisions of the Indenture and certain past defaults under the Indenture and their consequences with respect to such Series. Any such consent or waiver by the Holder of this Security shall be conclusive and binding upon such Holder and upon all future Holders of this Security and of any Security issued upon the registration of transfer hereof or in exchange hereof or in lieu hereof, whether or not notation of such consent or waiver is made upon this Security.

No reference herein to the Indenture and no provision of this Security or of the Indenture shall alter or impair the obligation of the Issuer, which is absolute and unconditional, to pay the principal of and any premium and Interest on this Security at the times, place and rate, and in the coin or currency, herein prescribed.

As provided in the Indenture and subject to certain limitations therein set forth, the transfer of this Security is registrable in the security register, upon surrender of this Security for registration of transfer at the office or agency of the Issuer in any place where the principal of and any premium and interest on this Security are payable, duly endorsed by, or accompanied by a written instrument of transfer in form satisfactory to the Issuer and the Registrar duly executed by, the Holder hereof or its attorney duly authorized in writing, and thereupon one or more new Securities of this Series and of like tenor, of authorized denominations and for the same aggregate principal amount, shall be issued to the designated transferee or transferees.

The Securities of this Series are issuable only in registered form without coupons in denominations of $2,000 and integral multiples of $1,000 in excess thereof. As provided in the Indenture and subject to certain limitations therein set forth, Securities of this Series are exchangeable for a like aggregate principal amount of Securities of this Series and of like tenor of a different authorized denomination, as requested by the Holder surrendering the same.

No service charge shall be made for any such registration of transfer or exchange, but the Issuer may require payment of a sum sufficient to cover any tax or other governmental charge payable in connection therewith.

Prior to due presentment of this Security for registration of transfer, the Issuer, the Trustee and any agent of the Issuer or the Trustee may treat the person in whose name this Security is registered as the owner hereof for all purposes, whether or not this Security is overdue, and none of the Issuer, the Trustee or any such agent shall be affected by notice to the contrary.

No recourse shall be had for the payment of the principal of (and premium, if any) or interest on this Security, or for any claim based hereon, or otherwise in respect hereof, or based on or in respect of the Indenture or any indenture supplemental thereto, against any incorporator, stockholder, officer or director, as such, past, present or future, of the Issuer or of any successor corporation, whether by virtue of any constitution, statute or rule of law, or by the enforcement of any assessment or penalty or otherwise, all such liability being, by the acceptance hereof and as part of the consideration for the issue hereof, expressly waived and released.

All terms used in this Security which are defined in the Indenture shall have the meanings assigned to them in the Indenture.

ASSIGNMENT FORM

To assign this Security, fill in the form below:

(I) or (we) assign and transfer this Security to: __________________

________________________

(Insert assignee’s legal name)

________________________

(Insert assignee’s soc. sec. or tax I.D. no.)

 _______________________

_______________________

_______________________   

(Print or type assignee’s name, address and zip code)

and irrevocably appoint  _______________

to transfer this Security on the books of the Issuer: The agent may substitute another to act for him.

Signatures must be guaranteed by an “eligible guarantor institution” meeting the requirements of the Registrar, which requirements include membership or participation in the Security Transfer Agent Medallion Program (“STAMP”) or such other “signature guarantee program” as may be determined by the Registrar in addition to, or in substitution for, STAMP, all in accordance with the Securities Exchange Act of 1934, as amended.

The undersigned hereby certifies that it is / is not an Affiliate of the Issuer and that, to its knowledge, the proposed transferee is / is not an Affiliate of the Issuer.

In connection with any transfer or exchange of any of the Securities evidenced by this certificate occurring prior to the date that is one year after the later of the date of original issuance of such Securities and the last date, if any, on which such Securities were owned by the Issuer or any Affiliate of the Issuer, the undersigned confirms that such Securities are being:

CHECK ONE BOX BELOW:

(1) ☐ acquired for the undersigned’s own account, without transfer; or

(2) ☐ transferred to the Issuer; or

(3) ☐ transferred to a Person that the undersigned reasonably believes is a “qualified institutional buyer” in compliance with Rule 144A under the Securities Act of 1933, as amended (the “Securities Act”); or

(4) ☐ transferred in an “offshore transaction” in compliance with Rule 904 of Regulation S under the Securities Act (provided that the transferor has furnished to the Trustee a signed letter containing certain representations and agreements, the form of which letter appears as Exhibit G to the Fifth Supplemental Indenture); or

(5) ☐ transferred pursuant to an exemption from registration provided by Rule 144 under the Securities Act or any other available exemption from the registration requirements of the Securities Act; or

(6) ☐ transferred pursuant to a registration statement which has become effective under the Securities Act.

Unless one of the boxes is checked, the Trustee will refuse to register any of the Securities evidenced by this certificate in the name of any person other than the registered Holder thereof; provided, however, that if box (5) is checked, the Issuer may require, prior to registering any such transfer of the Securities, in its sole discretion, such legal opinions, certifications and other information as the Issuer may reasonably request to confirm that such transfer is being made pursuant to an exemption from, or in a transaction not subject to, the registration requirements of the Securities Act, such as the exemption provided by Rule 144 under such Act.

TO BE COMPLETED BY PURCHASER IF BOX (1) OR (3) ABOVE IS CHECKED.

The undersigned represents and warrants that it is purchasing this Security for its own account or an account with respect to which it exercises sole investment discretion and that it and any such account is a “qualified institutional buyer” within the meaning of Rule 144A under the Securities Act, and is aware that the sale to it is being made in reliance on Rule 144A and acknowledges that it has received such information regarding the Issuer as the undersigned has requested pursuant to Rule 144A or has determined not to request such information and that it is aware that the transferor is relying upon the undersigned’s foregoing representations in order to claim the exemption from registration provided by Rule 144A.

____________________________

Dated:

Exhibit D

(Face of Note)

[Insert the Global Note Legend and Restricted Note Legend, as applicable, pursuant to the provisions of the Fifth Supplemental Indenture]

5.375% Senior Notes due 2033

ISIN: [___]

CUSIP: [___]

$[___]

No. [144A][Reg S] – [1]

OMNICOM GROUP INC., a New York corporation (the “Issuer,” which term includes any successor person under the Indenture hereinafter referred to), for value received, hereby promises to pay to CEDE & CO., or registered assigns, the principal sum of $[___] on June 15, 2033 and to pay interest thereon from the last interest payment date on which interest was paid or, if no interest has been paid, from June 15, 2025 semi-annually on June 15 and December 15 in each year, commencing December 15, 2025, at the rate of 5.375% per annum, set forth below. The interest so payable, and punctually paid or duly provided for, on any interest payment date shall, as provided in such Indenture, be paid to the person in whose name this Security (or one or more predecessor securities) is registered at the close of business on the regular record date for such interest, which shall be June 1 and December 1 (whether or not a Business Day), as the case may be, next preceding such interest payment date. Any such interest not so punctually paid or duly provided for shall forthwith cease to be payable to the Holder on such regular record date and may either be paid to the person in whose name this Security (or one or more predecessor securities) is registered at the close of business on a special record date for the payment of such defaulted interest to be fixed by the Trustee, notice whereof shall be given to Holders of Securities of this Series not less than 10 days prior to such special record date, or be paid at any time in any other lawful manner not inconsistent with the requirements of any securities exchange on which the Securities of this Series may be listed, and upon such notice as may be required by such exchange, all as more fully provided in said Indenture).

Payment of the principal of (and premium, if any) and interest on this Security will be made at the office or agency of the Issuer maintained for that purpose in The City of New York, New York, in accordance with the terms of the Indenture referred to on the reverse hereof in such coin or currency of the United States of America as at the time of payment is legal tender for payment of public and private debts; provided, however, that at the option of the Issuer payment of interest may be made by check mailed to the address of the person entitled thereto as such address shall appear in the Security register.

Reference is hereby made to the further provisions of this Security set forth on the reverse hereof, which further provisions shall for all purposes have the same effect as if set forth at this place.

This Security shall be deemed to be a contract made under the laws of the State of New York, and for all purposes shall be construed in accordance with and governed by the laws of said state.

Unless the certificate of authentication hereon has been executed by the Trustee referred to on the reverse hereof by manual signature, this Security shall not be entitled to any benefit under the Indenture or be valid or obligatory for any purpose.

IN WITNESS WHEREOF, the Issuer has caused this instrument to be duly executed.

This is one of the Securities of the Series designated therein referred to in the within-mentioned Indenture.

Reverse of Security

OMNICOM GROUP INC.

5.375% Senior Notes due 2033

This Security is one of a duly authorized issue of securities of the Issuer, designated as its 5.375% Senior Notes due 2033 (herein called the “Securities”), issued and to be issued in one or more Series under an Indenture, dated as of February 21, 2020 (the “Base Indenture”), between the Issuer and Deutsche Bank Trust Company Americas, as Trustee (herein called the “Trustee,” which term includes any successor trustee under the Indenture), as supplemented by the Fifth Supplemental Indenture dated as of December 2, 2025, between the Issuer and the Trustee (the “Fifth Supplemental Indenture” and, together with the Base Indenture, the “Indenture”), to which Indenture and all indentures supplemental thereto reference is hereby made for a statement of the respective rights, limitations of rights, duties and immunities thereunder of the Issuer, the Trustee and the Holders of the Securities and of the terms upon which the Securities are, and are to be, authenticated and delivered. This Security is one of the Series designated on the face hereof, initially limited in aggregate principal amount to $[___]. Capitalized terms used in this Security and not defined herein have the meaning ascribed thereto in the Indenture.

Deutsche Bank Trust Company Americas, the Trustee under the Indenture, has been appointed by the Issuer as Paying Agent, Registrar and custodian with regard to the Securities.

In case an Event of Default shall have occurred and be continuing, the principal of and accrued interest on all Securities may be declared, and upon said declaration, shall become due and payable, in the manner, with the effect and subject to the conditions provided for in the Indenture.

Prior to March 15, 2033 (the “Par Call Date”), the Issuer may redeem the Securities at its option, in whole or in part, at any time and from time to time, at a redemption price (expressed as a percentage of principal amount and rounded to three decimal places) equal to the greater of:

On or after the Par Call Date, the Issuer may redeem the Securities, in whole or in part, at any time and from time to time, at a redemption price equal to 100% of the principal amount of the Securities being redeemed plus accrued and unpaid interest thereon to the redemption date.

“Treasury Rate” means, with respect to any redemption date, the yield determined by the Issuer after 4:15 p.m., New York City time (or after such time as yields on U.S. government securities are posted daily by the Board of Governors of the Federal Reserve System), on the third Business Day preceding the redemption date based upon the yield or yields for the most recent day that appear after such time on such day in the most recent statistical release published by the Board of Governors of the Federal Reserve System designated as “Selected Interest Rates (Daily) — H.15” (or any successor designation or publication) (“H.15”) under the caption “U.S. government securities — Treasury constant maturities — Nominal” (or any successor caption or heading) (“H.15 TCM”). In determining the Treasury Rate, the Issuer shall select, as applicable: (1) the yield for the Treasury constant maturity on H.15 exactly equal to the period from the redemption date to the Par Call Date (the “Remaining Life”); or (2) if there is no such Treasury constant maturity on H.15 exactly equal to the Remaining Life, the two yields — one yield corresponding to the Treasury constant maturity on H.15 immediately shorter than and one yield corresponding to the Treasury constant maturity on H.15 immediately longer than the Remaining Life — and shall interpolate to the Par Call Date on a straight-line basis (using the actual number of days) using such yields and rounding the result to three decimal places; or (3) if there is no such Treasury constant maturity on H.15 shorter than or longer than the Remaining Life, the yield for the single Treasury constant maturity on H.15 closest to the Remaining Life. For purposes of this paragraph, the applicable Treasury constant maturity or maturities on H.15 shall be deemed to have a maturity date equal to the relevant number of months or years, as applicable, of such Treasury constant maturity from the redemption date.

If on the third Business Day preceding the redemption date H.15 TCM is no longer published, the Issuer shall calculate the Treasury Rate based on the rate per annum equal to the semi-annual equivalent yield to maturity at 11:00 a.m., New York City time, on the second Business Day preceding such redemption date of the United States Treasury security maturing on, or with a maturity that is closest to, the Par Call Date, as applicable. If there is no United States Treasury security maturing on the Par Call Date but there are two or more United States Treasury securities with a maturity date equally distant from the Par Call Date, one with a maturity date preceding the Par Call Date and one with a maturity date following the Par Call Date, the Issuer shall select the United States Treasury security with a maturity date preceding the Par Call Date. If there are two or more United States Treasury securities maturing on the Par Call Date or two or more United States Treasury securities meeting the criteria of the preceding sentence, the Issuer shall select from among these two or more United States Treasury securities the United States Treasury security that is trading closest to par based upon the average of the bid and asked prices for such United States Treasury securities at 11:00 a.m., New York City time. In determining the Treasury Rate in accordance with the terms of this paragraph, the semi-annual yield to maturity of the applicable United States Treasury security shall be based upon the average of the bid and asked prices (expressed as a percentage of principal amount) at 11:00 a.m., New York City time, of such United States Treasury security, and rounded to three decimal places.

Notice of any redemption will be mailed or electronically delivered (or otherwise transmitted in accordance with the Depository’s procedures) at least 10 days but not more than 60 days before the redemption date to each Holder of Securities to be redeemed at its registered address.

The Issuer’s actions and determinations in determining the redemption price shall be conclusive and binding for all purposes, absent manifest error. The calculation or determination of the redemption price shall be made by the Issuer or on its behalf by such person as the Issuer shall designate. For the avoidance of doubt, the calculation or determination of the redemption price, including the determination of any Treasury Rate, shall not be the obligation or responsibility of the Trustee or Paying Agent.

On and after the redemption date, interest shall cease to accrue on the Securities or any portion of the Securities called for redemption (unless the Issuer defaults in the payment of the redemption price and accrued interest). On or before 10:00 a.m. New York City time on the redemption date, the Issuer shall deposit with a Paying Agent (or the Trustee, if other than the Paying Agent) money sufficient to pay the redemption price of and accrued interest on the Securities to be redeemed on that date. If less than all of the Securities are to be redeemed, the Securities to be redeemed shall be selected by such method as the Trustee deems fair and appropriate, subject to the procedures of the Depository.

In the event of redemption of this Security in part only, a new Security or Securities of this Series and of like tenor for the unredeemed portion hereof shall be issued in the name of the Holder hereof upon the cancellation hereof; provided that in the case of a Global Security, an appropriate book-entry adjustment may be made in lieu of the issuance of a new Security.

The Indenture contains provisions that permit the Issuer to elect either (1) to defease and be discharged from the entire indebtedness of this Security or (2) to be released from its obligations under certain restrictive covenants and Events of Default with respect to this Security, in each case upon payment in full of the Securities and compliance with certain conditions set forth in the Indenture.

Upon the occurrence of a Change of Control Triggering Event with respect to the Securities of this Series, the Issuer shall be required to make an offer to repurchase the Securities of this Series on the terms set forth in Section 3.2 of the Fifth Supplemental Indenture.

If an Event of Default with respect to Securities of this Series shall occur and be continuing, the principal of the Securities of this Series may be declared due and payable in the manner and with the effect provided in the Indenture.

The Indenture permits the amendment thereof and the modification of the rights and obligations of the Issuer and the rights of the Holders of the Securities of each Series to be affected under the Indenture at any time by the Issuer and the Trustee with the consent of the Holders of a majority in principal amount of the Securities at the time outstanding of each Series to be affected, with certain exceptions as therein provided with respect to certain modifications or amendments which may not be made without the consent of each Holder of such Security affected thereby. The Indenture also permits certain amendments and modifications thereto from time to time by the Issuer and the Trustee without the consent of the Holders of any Series of the Securities to be affected thereby for certain specified purposes, including curing ambiguities, defects or inconsistencies and making any such change that does not adversely affect the legal rights of any Holder of such Series of the Securities, as provided therein.

The Indenture contains provisions permitting the Holders of specified percentages in principal amount of the Securities of each Series at the time outstanding, on behalf of the Holders of all Securities of such Series, to waive compliance by the Issuer with certain provisions of the Indenture and certain past defaults under the Indenture and their consequences with respect to such Series. Any such consent or waiver by the Holder of this Security shall be conclusive and binding upon such Holder and upon all future Holders of this Security and of any Security issued upon the registration of transfer hereof or in exchange hereof or in lieu hereof, whether or not notation of such consent or waiver is made upon this Security.

No reference herein to the Indenture and no provision of this Security or of the Indenture shall alter or impair the obligation of the Issuer, which is absolute and unconditional, to pay the principal of and any premium and Interest on this Security at the times, place and rate, and in the coin or currency, herein prescribed.

As provided in the Indenture and subject to certain limitations therein set forth, the transfer of this Security is registrable in the security register, upon surrender of this Security for registration of transfer at the office or agency of the Issuer in any place where the principal of and any premium and interest on this Security are payable, duly endorsed by, or accompanied by a written instrument of transfer in form satisfactory to the Issuer and the Registrar duly executed by, the Holder hereof or its attorney duly authorized in writing, and thereupon one or more new Securities of this Series and of like tenor, of authorized denominations and for the same aggregate principal amount, shall be issued to the designated transferee or transferees.

The Securities of this Series are issuable only in registered form without coupons in denominations of $2,000 and integral multiples of $1,000 in excess thereof. As provided in the Indenture and subject to certain limitations therein set forth, Securities of this Series are exchangeable for a like aggregate principal amount of Securities of this Series and of like tenor of a different authorized denomination, as requested by the Holder surrendering the same.

No service charge shall be made for any such registration of transfer or exchange, but the Issuer may require payment of a sum sufficient to cover any tax or other governmental charge payable in connection therewith.

Prior to due presentment of this Security for registration of transfer, the Issuer, the Trustee and any agent of the Issuer or the Trustee may treat the person in whose name this Security is registered as the owner hereof for all purposes, whether or not this Security is overdue, and none of the Issuer, the Trustee or any such agent shall be affected by notice to the contrary.

No recourse shall be had for the payment of the principal of (and premium, if any) or interest on this Security, or for any claim based hereon, or otherwise in respect hereof, or based on or in respect of the Indenture or any indenture supplemental thereto, against any incorporator, stockholder, officer or director, as such, past, present or future, of the Issuer or of any successor corporation, whether by virtue of any constitution, statute or rule of law, or by the enforcement of any assessment or penalty or otherwise, all such liability being, by the acceptance hereof and as part of the consideration for the issue hereof, expressly waived and released.

All terms used in this Security which are defined in the Indenture shall have the meanings assigned to them in the Indenture.

ASSIGNMENT FORM

To assign this Security, fill in the form below:

(I) or (we) assign and transfer this Security to: __________________

________________________

(Insert assignee’s legal name)

________________________

(Insert assignee’s soc. sec. or tax I.D. no.)

 _______________________

_______________________

_______________________   

(Print or type assignee’s name, address and zip code)

and irrevocably appoint     _______________

to transfer this Security on the books of the Issuer: The agent may substitute another to act for him.

Signatures must be guaranteed by an “eligible guarantor institution” meeting the requirements of the Registrar, which requirements include membership or participation in the Security Transfer Agent Medallion Program (“STAMP”) or such other “signature guarantee program” as may be determined by the Registrar in addition to, or in substitution for, STAMP, all in accordance with the Securities Exchange Act of 1934, as amended.

The undersigned hereby certifies that it  is /  is not an Affiliate of the Issuer and that, to its knowledge, the proposed transferee  is /  is not an Affiliate of the Issuer.

In connection with any transfer or exchange of any of the Securities evidenced by this certificate occurring prior to the date that is one year after the later of the date of original issuance of such Securities and the last date, if any, on which such Securities were owned by the Issuer or any Affiliate of the Issuer, the undersigned confirms that such Securities are being:

CHECK ONE BOX BELOW:

(1) ☐ acquired for the undersigned’s own account, without transfer; or

(2) ☐ transferred to the Issuer; or

(3) ☐ transferred to a Person that the undersigned reasonably believes is a “qualified institutional buyer” in compliance with Rule 144A under the Securities Act of 1933, as amended (the “Securities Act”); or

(4) ☐ transferred in an “offshore transaction” in compliance with Rule 904 of Regulation S under the Securities Act (provided that the transferor has furnished to the Trustee a signed letter containing certain representations and agreements, the form of which letter appears as Exhibit G to the Fifth Supplemental Indenture); or

(5) ☐ transferred pursuant to an exemption from registration provided by Rule 144 under the Securities Act or any other available exemption from the registration requirements of the Securities Act; or

(6) ☐ transferred pursuant to a registration statement which has become effective under the Securities Act.

Unless one of the boxes is checked, the Trustee will refuse to register any of the Securities evidenced by this certificate in the name of any person other than the registered Holder thereof; provided, however, that if box (5) is checked, the Issuer may require, prior to registering any such transfer of the Securities, in its sole discretion, such legal opinions, certifications and other information as the Issuer may reasonably request to confirm that such transfer is being made pursuant to an exemption from, or in a transaction not subject to, the registration requirements of the Securities Act, such as the exemption provided by Rule 144 under such Act.

TO BE COMPLETED BY PURCHASER IF BOX (1) OR (3) ABOVE IS CHECKED.

The undersigned represents and warrants that it is purchasing this Security for its own account or an account with respect to which it exercises sole investment discretion and that it and any such account is a “qualified institutional buyer” within the meaning of Rule 144A under the Securities Act, and is aware that the sale to it is being made in reliance on Rule 144A and acknowledges that it has received such information regarding the Issuer as the undersigned has requested pursuant to Rule 144A or has determined not to request such information and that it is aware that the transferor is relying upon the undersigned’s foregoing representations in order to claim the exemption from registration provided by Rule 144A.

____________________________

Dated:

Exhibit E

(Face of Note)

[Insert the Global Note Legend and Restricted Note Legend, as applicable, pursuant to the provisions of the Fifth Supplemental Indenture]

3.375% Senior Notes due 2041

ISIN: [___]

CUSIP: [___]

$[___]

No. [144A][Reg S] – [1]

OMNICOM GROUP INC., a New York corporation (the “Issuer,” which term includes any successor person under the Indenture hereinafter referred to), for value received, hereby promises to pay to CEDE & CO., or registered assigns, the principal sum of $[___] on March 1, 2041 and to pay interest thereon from the last interest payment date on which interest was paid or, if no interest has been paid, from September 1, 2025 semi-annually on March 1 and September 1 in each year, commencing March 1, 2026, at the rate of 3.375% per annum, set forth below. The interest so payable, and punctually paid or duly provided for, on any interest payment date shall, as provided in such Indenture, be paid to the person in whose name this Security (or one or more predecessor securities) is registered at the close of business on the regular record date for such interest, which shall be February 15 and August 15 (whether or not a Business Day), as the case may be, next preceding such interest payment date. Any such interest not so punctually paid or duly provided for shall forthwith cease to be payable to the Holder on such regular record date and may either be paid to the person in whose name this Security (or one or more predecessor securities) is registered at the close of business on a special record date for the payment of such defaulted interest to be fixed by the Trustee, notice whereof shall be given to Holders of Securities of this Series not less than 10 days prior to such special record date, or be paid at any time in any other lawful manner not inconsistent with the requirements of any securities exchange on which the Securities of this Series may be listed, and upon such notice as may be required by such exchange, all as more fully provided in said Indenture).

Payment of the principal of (and premium, if any) and interest on this Security will be made at the office or agency of the Issuer maintained for that purpose in The City of New York, New York, in accordance with the terms of the Indenture referred to on the reverse hereof in such coin or currency of the United States of America as at the time of payment is legal tender for payment of public and private debts; provided, however, that at the option of the Issuer payment of interest may be made by check mailed to the address of the person entitled thereto as such address shall appear in the Security register.

Reference is hereby made to the further provisions of this Security set forth on the reverse hereof, which further provisions shall for all purposes have the same effect as if set forth at this place.

This Security shall be deemed to be a contract made under the laws of the State of New York, and for all purposes shall be construed in accordance with and governed by the laws of said state.

Unless the certificate of authentication hereon has been executed by the Trustee referred to on the reverse hereof by manual signature, this Security shall not be entitled to any benefit under the Indenture or be valid or obligatory for any purpose.

IN WITNESS WHEREOF, the Issuer has caused this instrument to be duly executed.

This is one of the Securities of the Series designated therein referred to in the within-mentioned Indenture.

Reverse of Security

OMNICOM GROUP INC.

3.375% Senior Notes due 2041

This Security is one of a duly authorized issue of securities of the Issuer, designated as its 3.375% Senior Notes due 2041 (herein called the “Securities”), issued and to be issued in one or more Series under an Indenture, dated as of February 21, 2020 (the “Base Indenture”), between the Issuer and Deutsche Bank Trust Company Americas, as Trustee (herein called the “Trustee,” which term includes any successor trustee under the Indenture), as supplemented by the Fifth Supplemental Indenture dated as of December 2, 2025, between the Issuer and the Trustee (the “Fifth Supplemental Indenture” and, together with the Base Indenture, the “Indenture”), to which Indenture and all indentures supplemental thereto reference is hereby made for a statement of the respective rights, limitations of rights, duties and immunities thereunder of the Issuer, the Trustee and the Holders of the Securities and of the terms upon which the Securities are, and are to be, authenticated and delivered. This Security is one of the Series designated on the face hereof, initially limited in aggregate principal amount to $[___]. Capitalized terms used in this Security and not defined herein have the meaning ascribed thereto in the Indenture.

Deutsche Bank Trust Company Americas, the Trustee under the Indenture, has been appointed by the Issuer as Paying Agent, Registrar and custodian with regard to the Securities.

In case an Event of Default shall have occurred and be continuing, the principal of and accrued interest on all Securities may be declared, and upon said declaration, shall become due and payable, in the manner, with the effect and subject to the conditions provided for in the Indenture.

Prior to September 1, 2040 (the “Par Call Date”), the Issuer may redeem the Securities at its option, in whole or in part, at any time and from time to time, at a redemption price (expressed as a percentage of principal amount and rounded to three decimal places) equal to the greater of:

plus, in either case, accrued and unpaid interest thereon to the redemption date.

On or after the Par Call Date, the Issuer may redeem the Securities, in whole or in part, at any time and from time to time, at a redemption price equal to 100% of the principal amount of the Securities being redeemed plus accrued and unpaid interest thereon to the redemption date.

“Treasury Rate” means, with respect to any redemption date, the yield determined by the Issuer after 4:15 p.m., New York City time (or after such time as yields on U.S. government securities are posted daily by the Board of Governors of the Federal Reserve System), on the third Business Day preceding the redemption date based upon the yield or yields for the most recent day that appear after such time on such day in the most recent statistical release published by the Board of Governors of the Federal Reserve System designated as “Selected Interest Rates (Daily) — H.15” (or any successor designation or publication) (“H.15”) under the caption “U.S. government securities — Treasury constant maturities — Nominal” (or any successor caption or heading) (“H.15 TCM”). In determining the Treasury Rate, the Issuer shall select, as applicable: (1) the yield for the Treasury constant maturity on H.15 exactly equal to the period from the redemption date to the Par Call Date (the “Remaining Life”); or (2) if there is no such Treasury constant maturity on H.15 exactly equal to the Remaining Life, the two yields — one yield corresponding to the Treasury constant maturity on H.15 immediately shorter than and one yield corresponding to the Treasury constant maturity on H.15 immediately longer than the Remaining Life — and shall interpolate to the Par Call Date on a straight-line basis (using the actual number of days) using such yields and rounding the result to three decimal places; or (3) if there is no such Treasury constant maturity on H.15 shorter than or longer than the Remaining Life, the yield for the single Treasury constant maturity on H.15 closest to the Remaining Life. For purposes of this paragraph, the applicable Treasury constant maturity or maturities on H.15 shall be deemed to have a maturity date equal to the relevant number of months or years, as applicable, of such Treasury constant maturity from the redemption date.

If on the third Business Day preceding the redemption date H.15 TCM is no longer published, the Issuer shall calculate the Treasury Rate based on the rate per annum equal to the semi-annual equivalent yield to maturity at 11:00 a.m., New York City time, on the second Business Day preceding such redemption date of the United States Treasury security maturing on, or with a maturity that is closest to, the Par Call Date, as applicable. If there is no United States Treasury security maturing on the Par Call Date but there are two or more United States Treasury securities with a maturity date equally distant from the Par Call Date, one with a maturity date preceding the Par Call Date and one with a maturity date following the Par Call Date, the Issuer shall select the United States Treasury security with a maturity date preceding the Par Call Date. If there are two or more United States Treasury securities maturing on the Par Call Date or two or more United States Treasury securities meeting the criteria of the preceding sentence, the Issuer shall select from among these two or more United States Treasury securities the United States Treasury security that is trading closest to par based upon the average of the bid and asked prices for such United States Treasury securities at 11:00 a.m., New York City time. In determining the Treasury Rate in accordance with the terms of this paragraph, the semi-annual yield to maturity of the applicable United States Treasury security shall be based upon the average of the bid and asked prices (expressed as a percentage of principal amount) at 11:00 a.m., New York City time, of such United States Treasury security, and rounded to three decimal places.

Notice of any redemption will be mailed or electronically delivered (or otherwise transmitted in accordance with the Depository’s procedures) at least 10 days but not more than 60 days before the redemption date to each Holder of Securities to be redeemed at its registered address.

The Issuer’s actions and determinations in determining the redemption price shall be conclusive and binding for all purposes, absent manifest error. The calculation or determination of the redemption price shall be made by the Issuer or on its behalf by such person as the Issuer shall designate. For the avoidance of doubt, the calculation or determination of the redemption price, including the determination of any Treasury Rate, shall not be the obligation or responsibility of the Trustee or Paying Agent.

On and after the redemption date, interest shall cease to accrue on the Securities or any portion of the Securities called for redemption (unless the Issuer defaults in the payment of the redemption price and accrued interest). On or before 10:00 a.m. New York City time on the redemption date, the Issuer shall deposit with a Paying Agent (or the Trustee, if other than the Paying Agent) money sufficient to pay the redemption price of and accrued interest on the Securities to be redeemed on that date. If less than all of the Securities are to be redeemed, the Securities to be redeemed shall be selected by such method as the Trustee deems fair and appropriate, subject to the procedures of the Depository.

In the event of redemption of this Security in part only, a new Security or Securities of this Series and of like tenor for the unredeemed portion hereof shall be issued in the name of the Holder hereof upon the cancellation hereof; provided that in the case of a Global Security, an appropriate book-entry adjustment may be made in lieu of the issuance of a new Security.

The Indenture contains provisions that permit the Issuer to elect either (1) to defease and be discharged from the entire indebtedness of this Security or (2) to be released from its obligations under certain restrictive covenants and Events of Default with respect to this Security, in each case upon payment in full of the Securities and compliance with certain conditions set forth in the Indenture.

Upon the occurrence of a Change of Control Triggering Event with respect to the Securities of this Series, the Issuer shall be required to make an offer to repurchase the Securities of this Series on the terms set forth in Section 3.2 of the Fifth Supplemental Indenture.

If an Event of Default with respect to Securities of this Series shall occur and be continuing, the principal of the Securities of this Series may be declared due and payable in the manner and with the effect provided in the Indenture.

The Indenture permits the amendment thereof and the modification of the rights and obligations of the Issuer and the rights of the Holders of the Securities of each Series to be affected under the Indenture at any time by the Issuer and the Trustee with the consent of the Holders of a majority in principal amount of the Securities at the time outstanding of each Series to be affected, with certain exceptions as therein provided with respect to certain modifications or amendments which may not be made without the consent of each Holder of such Security affected thereby. The Indenture also permits certain amendments and modifications thereto from time to time by the Issuer and the Trustee without the consent of the Holders of any Series of the Securities to be affected thereby for certain specified purposes, including curing ambiguities, defects or inconsistencies and making any such change that does not adversely affect the legal rights of any Holder of such Series of the Securities, as provided therein.

The Indenture contains provisions permitting the Holders of specified percentages in principal amount of the Securities of each Series at the time outstanding, on behalf of the Holders of all Securities of such Series, to waive compliance by the Issuer with certain provisions of the Indenture and certain past defaults under the Indenture and their consequences with respect to such Series. Any such consent or waiver by the Holder of this Security shall be conclusive and binding upon such Holder and upon all future Holders of this Security and of any Security issued upon the registration of transfer hereof or in exchange hereof or in lieu hereof, whether or not notation of such consent or waiver is made upon this Security.

No reference herein to the Indenture and no provision of this Security or of the Indenture shall alter or impair the obligation of the Issuer, which is absolute and unconditional, to pay the principal of and any premium and Interest on this Security at the times, place and rate, and in the coin or currency, herein prescribed.

As provided in the Indenture and subject to certain limitations therein set forth, the transfer of this Security is registrable in the security register, upon surrender of this Security for registration of transfer at the office or agency of the Issuer in any place where the principal of and any premium and interest on this Security are payable, duly endorsed by, or accompanied by a written instrument of transfer in form satisfactory to the Issuer and the Registrar duly executed by, the Holder hereof or its attorney duly authorized in writing, and thereupon one or more new Securities of this Series and of like tenor, of authorized denominations and for the same aggregate principal amount, shall be issued to the designated transferee or transferees.

The Securities of this Series are issuable only in registered form without coupons in denominations of $2,000 and integral multiples of $1,000 in excess thereof. As provided in the Indenture and subject to certain limitations therein set forth, Securities of this Series are exchangeable for a like aggregate principal amount of Securities of this Series and of like tenor of a different authorized denomination, as requested by the Holder surrendering the same.

No service charge shall be made for any such registration of transfer or exchange, but the Issuer may require payment of a sum sufficient to cover any tax or other governmental charge payable in connection therewith.

Prior to due presentment of this Security for registration of transfer, the Issuer, the Trustee and any agent of the Issuer or the Trustee may treat the person in whose name this Security is registered as the owner hereof for all purposes, whether or not this Security is overdue, and none of the Issuer, the Trustee or any such agent shall be affected by notice to the contrary.

No recourse shall be had for the payment of the principal of (and premium, if any) or interest on this Security, or for any claim based hereon, or otherwise in respect hereof, or based on or in respect of the Indenture or any indenture supplemental thereto, against any incorporator, stockholder, officer or director, as such, past, present or future, of the Issuer or of any successor corporation, whether by virtue of any constitution, statute or rule of law, or by the enforcement of any assessment or penalty or otherwise, all such liability being, by the acceptance hereof and as part of the consideration for the issue hereof, expressly waived and released.

All terms used in this Security which are defined in the Indenture shall have the meanings assigned to them in the Indenture.

ASSIGNMENT FORM

To assign this Security, fill in the form below:

(I) or (we) assign and transfer this Security to: __________________

________________________

(Insert assignee’s legal name)

________________________

(Insert assignee’s soc. sec. or tax I.D. no.)

 _______________________

_______________________

_______________________   

(Print or type assignee’s name, address and zip code)

and irrevocably appoint     _______________

to transfer this Security on the books of the Issuer: The agent may substitute another to act for him.

Signatures must be guaranteed by an “eligible guarantor institution” meeting the requirements of the Registrar, which requirements include membership or participation in the Security Transfer Agent Medallion Program (“STAMP”) or such other “signature guarantee program” as may be determined by the Registrar in addition to, or in substitution for, STAMP, all in accordance with the Securities Exchange Act of 1934, as amended.

The undersigned hereby certifies that it  is /  is not an Affiliate of the Issuer and that, to its knowledge, the proposed transferee  is /  is not an Affiliate of the Issuer.

In connection with any transfer or exchange of any of the Securities evidenced by this certificate occurring prior to the date that is one year after the later of the date of original issuance of such Securities and the last date, if any, on which such Securities were owned by the Issuer or any Affiliate of the Issuer, the undersigned confirms that such Securities are being:

CHECK ONE BOX BELOW:

(1) ☐ acquired for the undersigned’s own account, without transfer; or

(2) ☐ transferred to the Issuer; or

(3) ☐ transferred to a Person that the undersigned reasonably believes is a “qualified institutional buyer” in compliance with Rule 144A under the Securities Act of 1933, as amended (the “Securities Act”); or

(4) ☐ transferred in an “offshore transaction” in compliance with Rule 904 of Regulation S under the Securities Act (provided that the transferor has furnished to the Trustee a signed letter containing certain representations and agreements, the form of which letter appears as Exhibit G to the Fifth Supplemental Indenture); or

(5) ☐ transferred pursuant to an exemption from registration provided by Rule 144 under the Securities Act or any other available exemption from the registration requirements of the Securities Act; or

(6) ☐ transferred pursuant to a registration statement which has become effective under the Securities Act.

Unless one of the boxes is checked, the Trustee will refuse to register any of the Securities evidenced by this certificate in the name of any person other than the registered Holder thereof; provided, however, that if box (5) is checked, the Issuer may require, prior to registering any such transfer of the Securities, in its sole discretion, such legal opinions, certifications and other information as the Issuer may reasonably request to confirm that such transfer is being made pursuant to an exemption from, or in a transaction not subject to, the registration requirements of the Securities Act, such as the exemption provided by Rule 144 under such Act.

TO BE COMPLETED BY PURCHASER IF BOX (1) OR (3) ABOVE IS CHECKED.

The undersigned represents and warrants that it is purchasing this Security for its own account or an account with respect to which it exercises sole investment discretion and that it and any such account is a “qualified institutional buyer” within the meaning of Rule 144A under the Securities Act, and is aware that the sale to it is being made in reliance on Rule 144A and acknowledges that it has received such information regarding the Issuer as the undersigned has requested pursuant to Rule 144A or has determined not to request such information and that it is aware that the transferor is relying upon the undersigned’s foregoing representations in order to claim the exemption from registration provided by Rule 144A.

____________________________

Dated:

Exhibit F

(Face of Note)

[Insert the Global Note Legend and Restricted Note Legend, as applicable, pursuant to the provisions of the Fifth Supplemental Indenture]

5.400% Senior Notes due 2048

ISIN: [___]

CUSIP: [___]

$[___]

No. [144A][Reg S] – [1]

OMNICOM GROUP INC., a New York corporation (the “Issuer,” which term includes any successor person under the Indenture hereinafter referred to), for value received, hereby promises to pay to CEDE & CO., or registered assigns, the principal sum of $[___] on October 1, 2048 and to pay interest thereon from the last interest payment date on which interest was paid or, if no interest has been paid, from October 1, 2025 semi-annually on April 1 and October 1 in each year, commencing April 1, 2026, at the rate of 5.400% per annum, set forth below. The interest so payable, and punctually paid or duly provided for, on any interest payment date shall, as provided in such Indenture, be paid to the person in whose name this Security (or one or more predecessor securities) is registered at the close of business on the regular record date for such interest, which shall be March 15 and September 15 (whether or not a Business Day), as the case may be, next preceding such interest payment date. Any such interest not so punctually paid or duly provided for shall forthwith cease to be payable to the Holder on such regular record date and may either be paid to the person in whose name this Security (or one or more predecessor securities) is registered at the close of business on a special record date for the payment of such defaulted interest to be fixed by the Trustee, notice whereof shall be given to Holders of Securities of this Series not less than 10 days prior to such special record date, or be paid at any time in any other lawful manner not inconsistent with the requirements of any securities exchange on which the Securities of this Series may be listed, and upon such notice as may be required by such exchange, all as more fully provided in said Indenture).

Payment of the principal of (and premium, if any) and interest on this Security will be made at the office or agency of the Issuer maintained for that purpose in The City of New York, New York, in accordance with the terms of the Indenture referred to on the reverse hereof in such coin or currency of the United States of America as at the time of payment is legal tender for payment of public and private debts; provided, however, that at the option of the Issuer payment of interest may be made by check mailed to the address of the person entitled thereto as such address shall appear in the Security register.

Reference is hereby made to the further provisions of this Security set forth on the reverse hereof, which further provisions shall for all purposes have the same effect as if set forth at this place.

This Security shall be deemed to be a contract made under the laws of the State of New York, and for all purposes shall be construed in accordance with and governed by the laws of said state.

Unless the certificate of authentication hereon has been executed by the Trustee referred to on the reverse hereof by manual signature, this Security shall not be entitled to any benefit under the Indenture or be valid or obligatory for any purpose.

IN WITNESS WHEREOF, the Issuer has caused this instrument to be duly executed.

This is one of the Securities of the Series designated therein referred to in the within-mentioned Indenture.

Reverse of Security

OMNICOM GROUP INC.

5.400% Senior Notes due 2048

This Security is one of a duly authorized issue of securities of the Issuer, designated as its 5.400% Senior Notes due 2048 (herein called the “Securities”), issued and to be issued in one or more Series under an Indenture, dated as of February 21, 2020 (the “Base Indenture”), between the Issuer and Deutsche Bank Trust Company Americas, as Trustee (herein called the “Trustee,” which term includes any successor trustee under the Indenture), as supplemented by the Fifth Supplemental Indenture dated as of December 2, 2025, between the Issuer and the Trustee (the “Fifth Supplemental Indenture” and, together with the Base Indenture, the “Indenture”), to which Indenture and all indentures supplemental thereto reference is hereby made for a statement of the respective rights, limitations of rights, duties and immunities thereunder of the Issuer, the Trustee and the Holders of the Securities and of the terms upon which the Securities are, and are to be, authenticated and delivered. This Security is one of the Series designated on the face hereof, initially limited in aggregate principal amount to $[___]. Capitalized terms used in this Security and not defined herein have the meaning ascribed thereto in the Indenture.

Deutsche Bank Trust Company Americas, the Trustee under the Indenture, has been appointed by the Issuer as Paying Agent, Registrar and custodian with regard to the Securities.

In case an Event of Default shall have occurred and be continuing, the principal of and accrued interest on all Securities may be declared, and upon said declaration, shall become due and payable, in the manner, with the effect and subject to the conditions provided for in the Indenture.

Prior to April 1, 2048 (the “Par Call Date”), the Issuer may redeem the Securities at its option, in whole or in part, at any time and from time to time, at a redemption price (expressed as a percentage of principal amount and rounded to three decimal places) equal to the greater of:

On or after the Par Call Date, the Issuer may redeem the Securities, in whole or in part, at any time and from time to time, at a redemption price equal to 100% of the principal amount of the Securities being redeemed plus accrued and unpaid interest thereon to the redemption date.

“Treasury Rate” means, with respect to any redemption date, the yield determined by the Issuer after 4:15 p.m., New York City time (or after such time as yields on U.S. government securities are posted daily by the Board of Governors of the Federal Reserve System), on the third Business Day preceding the redemption date based upon the yield or yields for the most recent day that appear after such time on such day in the most recent statistical release published by the Board of Governors of the Federal Reserve System designated as “Selected Interest Rates (Daily) — H.15” (or any successor designation or publication) (“H.15”) under the caption “U.S. government securities — Treasury constant maturities — Nominal” (or any successor caption or heading) (“H.15 TCM”). In determining the Treasury Rate, the Issuer shall select, as applicable: (1) the yield for the Treasury constant maturity on H.15 exactly equal to the period from the redemption date to the Par Call Date (the “Remaining Life”); or (2) if there is no such Treasury constant maturity on H.15 exactly equal to the Remaining Life, the two yields — one yield corresponding to the Treasury constant maturity on H.15 immediately shorter than and one yield corresponding to the Treasury constant maturity on H.15 immediately longer than the Remaining Life — and shall interpolate to the Par Call Date on a straight-line basis (using the actual number of days) using such yields and rounding the result to three decimal places; or (3) if there is no such Treasury constant maturity on H.15 shorter than or longer than the Remaining Life, the yield for the single Treasury constant maturity on H.15 closest to the Remaining Life. For purposes of this paragraph, the applicable Treasury constant maturity or maturities on H.15 shall be deemed to have a maturity date equal to the relevant number of months or years, as applicable, of such Treasury constant maturity from the redemption date.

If on the third Business Day preceding the redemption date H.15 TCM is no longer published, the Issuer shall calculate the Treasury Rate based on the rate per annum equal to the semi-annual equivalent yield to maturity at 11:00 a.m., New York City time, on the second Business Day preceding such redemption date of the United States Treasury security maturing on, or with a maturity that is closest to, the Par Call Date, as applicable. If there is no United States Treasury security maturing on the Par Call Date but there are two or more United States Treasury securities with a maturity date equally distant from the Par Call Date, one with a maturity date preceding the Par Call Date and one with a maturity date following the Par Call Date, the Issuer shall select the United States Treasury security with a maturity date preceding the Par Call Date. If there are two or more United States Treasury securities maturing on the Par Call Date or two or more United States Treasury securities meeting the criteria of the preceding sentence, the Issuer shall select from among these two or more United States Treasury securities the United States Treasury security that is trading closest to par based upon the average of the bid and asked prices for such United States Treasury securities at 11:00 a.m., New York City time. In determining the Treasury Rate in accordance with the terms of this paragraph, the semi-annual yield to maturity of the applicable United States Treasury security shall be based upon the average of the bid and asked prices (expressed as a percentage of principal amount) at 11:00 a.m., New York City time, of such United States Treasury security, and rounded to three decimal places.

Notice of any redemption will be mailed or electronically delivered (or otherwise transmitted in accordance with the Depository’s procedures) at least 10 days but not more than 60 days before the redemption date to each Holder of Securities to be redeemed at its registered address.

The Issuer’s actions and determinations in determining the redemption price shall be conclusive and binding for all purposes, absent manifest error. The calculation or determination of the redemption price shall be made by the Issuer or on its behalf by such person as the Issuer shall designate. For the avoidance of doubt, the calculation or determination of the redemption price, including the determination of any Treasury Rate, shall not be the obligation or responsibility of the Trustee or Paying Agent.

On and after the redemption date, interest shall cease to accrue on the Securities or any portion of the Securities called for redemption (unless the Issuer defaults in the payment of the redemption price and accrued interest). On or before 10:00 a.m. New York City time on the redemption date, the Issuer shall deposit with a Paying Agent (or the Trustee, if other than the Paying Agent) money sufficient to pay the redemption price of and accrued interest on the Securities to be redeemed on that date. If less than all of the Securities are to be redeemed, the Securities to be redeemed shall be selected by such method as the Trustee deems fair and appropriate, subject to the procedures of the Depository.

In the event of redemption of this Security in part only, a new Security or Securities of this Series and of like tenor for the unredeemed portion hereof shall be issued in the name of the Holder hereof upon the cancellation hereof; provided that in the case of a Global Security, an appropriate book-entry adjustment may be made in lieu of the issuance of a new Security.

The Indenture contains provisions that permit the Issuer to elect either (1) to defease and be discharged from the entire indebtedness of this Security or (2) to be released from its obligations under certain restrictive covenants and Events of Default with respect to this Security, in each case upon payment in full of the Securities and compliance with certain conditions set forth in the Indenture.

Upon the occurrence of a Change of Control Triggering Event with respect to the Securities of this Series, the Issuer shall be required to make an offer to repurchase the Securities of this Series on the terms set forth in Section 3.2 of the Fifth Supplemental Indenture.

If an Event of Default with respect to Securities of this Series shall occur and be continuing, the principal of the Securities of this Series may be declared due and payable in the manner and with the effect provided in the Indenture.

The Indenture permits the amendment thereof and the modification of the rights and obligations of the Issuer and the rights of the Holders of the Securities of each Series to be affected under the Indenture at any time by the Issuer and the Trustee with the consent of the Holders of a majority in principal amount of the Securities at the time outstanding of each Series to be affected, with certain exceptions as therein provided with respect to certain modifications or amendments which may not be made without the consent of each Holder of such Security affected thereby. The Indenture also permits certain amendments and modifications thereto from time to time by the Issuer and the Trustee without the consent of the Holders of any Series of the Securities to be affected thereby for certain specified purposes, including curing ambiguities, defects or inconsistencies and making any such change that does not adversely affect the legal rights of any Holder of such Series of the Securities, as provided therein.

The Indenture contains provisions permitting the Holders of specified percentages in principal amount of the Securities of each Series at the time outstanding, on behalf of the Holders of all Securities of such Series, to waive compliance by the Issuer with certain provisions of the Indenture and certain past defaults under the Indenture and their consequences with respect to such Series. Any such consent or waiver by the Holder of this Security shall be conclusive and binding upon such Holder and upon all future Holders of this Security and of any Security issued upon the registration of transfer hereof or in exchange hereof or in lieu hereof, whether or not notation of such consent or waiver is made upon this Security.

No reference herein to the Indenture and no provision of this Security or of the Indenture shall alter or impair the obligation of the Issuer, which is absolute and unconditional, to pay the principal of and any premium and Interest on this Security at the times, place and rate, and in the coin or currency, herein prescribed.

As provided in the Indenture and subject to certain limitations therein set forth, the transfer of this Security is registrable in the security register, upon surrender of this Security for registration of transfer at the office or agency of the Issuer in any place where the principal of and any premium and interest on this Security are payable, duly endorsed by, or accompanied by a written instrument of transfer in form satisfactory to the Issuer and the Registrar duly executed by, the Holder hereof or its attorney duly authorized in writing, and thereupon one or more new Securities of this Series and of like tenor, of authorized denominations and for the same aggregate principal amount, shall be issued to the designated transferee or transferees.

The Securities of this Series are issuable only in registered form without coupons in denominations of $2,000 and integral multiples of $1,000 in excess thereof. As provided in the Indenture and subject to certain limitations therein set forth, Securities of this Series are exchangeable for a like aggregate principal amount of Securities of this Series and of like tenor of a different authorized denomination, as requested by the Holder surrendering the same.

No service charge shall be made for any such registration of transfer or exchange, but the Issuer may require payment of a sum sufficient to cover any tax or other governmental charge payable in connection therewith.

Prior to due presentment of this Security for registration of transfer, the Issuer, the Trustee and any agent of the Issuer or the Trustee may treat the person in whose name this Security is registered as the owner hereof for all purposes, whether or not this Security is overdue, and none of the Issuer, the Trustee or any such agent shall be affected by notice to the contrary.

No recourse shall be had for the payment of the principal of (and premium, if any) or interest on this Security, or for any claim based hereon, or otherwise in respect hereof, or based on or in respect of the Indenture or any indenture supplemental thereto, against any incorporator, stockholder, officer or director, as such, past, present or future, of the Issuer or of any successor corporation, whether by virtue of any constitution, statute or rule of law, or by the enforcement of any assessment or penalty or otherwise, all such liability being, by the acceptance hereof and as part of the consideration for the issue hereof, expressly waived and released.

All terms used in this Security which are defined in the Indenture shall have the meanings assigned to them in the Indenture.

ASSIGNMENT FORM

To assign this Security, fill in the form below:

(I) or (we) assign and transfer this Security to: __________________

________________________

(Insert assignee’s legal name)

________________________

(Insert assignee’s soc. sec. or tax I.D. no.)

 _______________________

_______________________

_______________________   

(Print or type assignee’s name, address and zip code)

and irrevocably appoint     _______________

to transfer this Security on the books of the Issuer: The agent may substitute another to act for him.

Signatures must be guaranteed by an “eligible guarantor institution” meeting the requirements of the Registrar, which requirements include membership or participation in the Security Transfer Agent Medallion Program (“STAMP”) or such other “signature guarantee program” as may be determined by the Registrar in addition to, or in substitution for, STAMP, all in accordance with the Securities Exchange Act of 1934, as amended.

The undersigned hereby certifies that it  is /  is not an Affiliate of the Issuer and that, to its knowledge, the proposed transferee  is /  is not an Affiliate of the Issuer.

In connection with any transfer or exchange of any of the Securities evidenced by this certificate occurring prior to the date that is one year after the later of the date of original issuance of such Securities and the last date, if any, on which such Securities were owned by the Issuer or any Affiliate of the Issuer, the undersigned confirms that such Securities are being:

CHECK ONE BOX BELOW:

(1) ☐ acquired for the undersigned’s own account, without transfer; or

(2) ☐ transferred to the Issuer; or

(3) ☐ transferred to a Person that the undersigned reasonably believes is a “qualified institutional buyer” in compliance with Rule 144A under the Securities Act of 1933, as amended (the “Securities Act”); or

(4) ☐ transferred in an “offshore transaction” in compliance with Rule 904 of Regulation S under the Securities Act (provided that the transferor has furnished to the Trustee a signed letter containing certain representations and agreements, the form of which letter appears as Exhibit G to the Fifth Supplemental Indenture); or

(5) ☐ transferred pursuant to an exemption from registration provided by Rule 144 under the Securities Act or any other available exemption from the registration requirements of the Securities Act; or

(6) ☐ transferred pursuant to a registration statement which has become effective under the Securities Act.

Unless one of the boxes is checked, the Trustee will refuse to register any of the Securities evidenced by this certificate in the name of any person other than the registered Holder thereof; provided, however, that if box (5) is checked, the Issuer may require, prior to registering any such transfer of the Securities, in its sole discretion, such legal opinions, certifications and other information as the Issuer may reasonably request to confirm that such transfer is being made pursuant to an exemption from, or in a transaction not subject to, the registration requirements of the Securities Act, such as the exemption provided by Rule 144 under such Act.

TO BE COMPLETED BY PURCHASER IF BOX (1) OR (3) ABOVE IS CHECKED.

The undersigned represents and warrants that it is purchasing this Security for its own account or an account with respect to which it exercises sole investment discretion and that it and any such account is a “qualified institutional buyer” within the meaning of Rule 144A under the Securities Act, and is aware that the sale to it is being made in reliance on Rule 144A and acknowledges that it has received such information regarding the Issuer as the undersigned has requested pursuant to Rule 144A or has determined not to request such information and that it is aware that the transferor is relying upon the undersigned’s foregoing representations in order to claim the exemption from registration provided by Rule 144A.

____________________________

Dated:

Exhibit G

FORM OF CERTIFICATE TO BE DELIVERED IN CONNECTION WITH TRANSFERS PURSUANT TO REGULATION S

[Date]

Omnicom Group Inc.

c/o Deutsche Bank Trust Company Americas

Trust and Securities Services

1 Columbus Circle, 4th Floor

Mail Stop: NYC01-0417

New York, New York 10019, USA

Attention: Transfer Operations/Omnicom

Ladies and Gentlemen:

In connection with our proposed sale of $[_] aggregate principal amount of the Notes, we confirm that such sale has been effected pursuant to and in accordance with Regulation S under the United States Securities Act of 1933, as amended (the “Securities Act”), and, accordingly, we represent that:

(a) the offer of the Notes was not made to a person in the United States;

(b) either (i) at the time the buy order was originated, the transferee was outside the United States or we and any person acting on our behalf reasonably believed that the transferee was outside the United States or (ii) the transaction was executed in, on or through the facilities of a designated off-shore securities market and neither we nor any person acting on our behalf knows that the transaction has been pre-arranged with a buyer in the United States;

(c) no directed selling efforts have been made in the United States in contravention of the requirements of Rule 903(a)(2) or Rule 904(a)(2) of Regulation S, as applicable; and

(d) the transaction is not part of a plan or scheme to evade the registration requirements of the Securities Act.

In addition, if the sale is made during a restricted period and the provisions of Rule 903(b)(2), Rule 903(b)(3) or Rule 904(b)(1) of Regulation S are applicable thereto, we confirm that such sale has been made in accordance with the applicable provisions of Rule 903(b)(2), Rule 903(b)(3) or Rule 904(b)(1), as the case may be.

We also hereby certify that we [are] [are not] an Affiliate of the Issuer and, to our knowledge, the transferee of the Notes [is] [is not] an Affiliate of the Issuer.

You and the Issuer are entitled to rely upon this letter and are irrevocably authorized to produce this letter or a copy hereof to any interested party in any administrative or legal proceedings or official inquiry with respect to the matters covered hereby. Terms used in this certificate have the meanings set forth in Regulation S.

Very truly yours,

[Name of Transferor]

Exhibit 4.8

Execution Version

REGISTRATION RIGHTS AGREEMENT

by and between

Omnicom Group Inc., as Issuer,

and

BofA Securities, Inc.,

J.P. Morgan Securities LLC,

Wells Fargo Securities, LLC,

Barclays Capital Inc.,

BNP Paribas Securities Corp.,

Citigroup Global Markets Inc.,

Deutsche Bank Securities Inc.,

and

HSBC Securities (USA) Inc., as Dealer Managers

Dated as of December 2, 2025

REGISTRATION RIGHTS AGREEMENT

This Registration Rights Agreement (this “Agreement”) is made and entered into this 2nd day of December, 2025, by and among Omnicom Group Inc., a New York corporation, (the “Company”), and BofA Securities, Inc., J.P. Morgan Securities LLC, Wells Fargo Securities, LLC, Barclays Capital Inc., BNP Paribas Securities Corp., Citigroup Global Markets Inc., Deutsche Bank Securities Inc. and HSBC Securities (USA) Inc. (collectively, the “Dealer Managers”).

This Agreement is made pursuant to the Offering Memorandum and Consent Solicitation Statement dated August 11, 2025 (as amended or supplemented, the “Offering Memorandum”), which provides for the offers by the Company to exchange (collectively, the “Private Exchange Offers”) any and all of the outstanding 4.650% Notes due 2028, 4.750% Notes due 2030, 2.400% Notes due 2031, 5.375% Notes due 2033, 3.375% Notes due 2041 and 5.400% Notes due 2048 (collectively, the “Old IPG Notes”) issued by The Interpublic Group of Companies, Inc., a Delaware corporation (“IPG”), and held by certain eligible holders in exchange for newly issued debt securities of the Company (the “New Omnicom Notes”), in each case maturing on the same date and bearing an interest rate of the same amount per annum as the applicable series of Old IPG Notes for which they are exchanged and cash, on the terms and subject to the conditions set forth in the Offering Memorandum. The execution of this Agreement is a condition to the consummation of the Original Exchange Offer (as defined below).

In consideration of the foregoing, the parties hereto agree as follows:

1. Definitions. As used in this Agreement, the following capitalized defined terms shall have the following meanings:

“Affiliate” shall mean an “affiliate” as that term is defined in Rule 405 under the Securities Act.

“Agreement” shall have the meaning set forth in the preamble.

“Automatic Shelf Registration Statement” shall mean an “automatic shelf registration statement” as that term is defined in Rule 405 under the Securities Act.

“Company” shall have the meaning set forth in the preamble and shall also include the Company’s successors.

“Dealer Managers” shall have the meaning set forth in the preamble.

“Dealer Manager Agreement” means the Dealer Manager and Solicitation Agent Agreement, dated August 11, 2025, by and among the Company and the Dealer Managers.

“Depositary” shall mean The Depository Trust Company, or any other depositary appointed by the Company; provided, however, that such depositary must have an address in the Borough of Manhattan, in the City of New York.

“Exchange Date” shall have the meaning set forth in the Dealer Manager Agreement.

“Exchange Offer” means the offer by the Company to exchange each Series of Registrable Securities for the corresponding Series of Exchange Securities pursuant to Section 2.1.

“Exchange Offer Registration Statement” shall mean an exchange offer registration statement on Form S-4 (or, if applicable, on another appropriate form), and all amendments and supplements to such registration statement, including the Prospectus contained therein, all exhibits thereto and all material incorporated or deemed incorporated by reference therein.

“Exchange Period” shall have the meaning set forth in Section 2.1.

“Exchange Securities” shall mean with respect to each series of New Omnicom Notes, a new series of notes maturing on the same date and bearing interest at the same rate per annum as the corresponding series of New Omnicom Notes (each such series of Exchange Securities, a “Series of Exchange Securities”), in each case issued by the Company under the Indenture, containing terms identical to the applicable Series of New Omnicom Notes in all material respects (except for restrictions on transfers and restrictive legends), to be offered to Holders of the applicable Series of New Omnicom Notes in exchange for the corresponding Series of Registrable Securities pursuant to the Exchange Offer.

“Holder” shall mean each Person who becomes the registered owner of Registrable Securities under the Indenture and each Participating Broker-Dealer that holds Exchange Securities for so long as such Participating Broker-Dealer is required to deliver a Prospectus in connection with any resale of such Exchange Securities.

“Indenture” shall mean the Indenture, dated as of February 21, 2020 between the Company and Deutsche Bank Trust Company Americas, as the trustee, as the same may be amended, supplemented, waived or otherwise modified from time to time in accordance with the terms thereof.

“IPG” shall have the meaning set forth in the preamble.

“Majority Holders” shall mean the Holders of a majority of the aggregate principal amount of outstanding Registrable Securities; provided, that whenever the consent or approval of Holders of a specified percentage of Registrable Securities is required hereunder, Registrable Securities held by the Company or any Affiliate of the Company shall be disregarded in determining whether such consent or approval was given by the Holders of such required percentage amount. For purposes of this definition, “outstanding” shall have the meaning prescribed in Section 2.09 of the Indenture.

“New Omnicom Notes” shall have the meaning set forth in the preamble.

“Offering Memorandum” shall have the meaning set forth in the preamble.

“Old IPG Notes” shall have the meaning set forth in the preamble.

“Original Exchange Offer” means the offer by the Company to exchange any and all outstanding Old IPG Notes for New Omnicom Notes, on the terms and conditions set forth in the Offering Memorandum.

“Participating Broker-Dealers” shall mean the Dealer Managers and any other broker- dealer which makes a market in the New Omnicom Notes and exchanges Registrable Securities in the Exchange Offer for Exchange Securities.

“Person” shall mean an individual, partnership (general or limited), corporation, limited liability company, trust or unincorporated organization, or a government or agency or political subdivision thereof.

“Private Exchange Offers” shall have the meaning set forth in the preamble.

“Prospectus” shall mean the prospectus included in a Registration Statement, including any preliminary prospectus, and any such prospectus as amended or supplemented by any prospectus supplement, including any such prospectus supplement with respect to the terms of the offering of any portion of the Registrable Securities covered by a Shelf Registration Statement, and by all other amendments and supplements to a prospectus, including post- effective amendments, and in each case including all material incorporated or deemed incorporated by reference therein.

“Registrable Securities” shall mean the New Omnicom Notes; provided, however, that the New Omnicom Notes shall cease to be Registrable Securities when (i) a Registration Statement with respect to such New Omnicom Notes shall have been declared or otherwise become effective under the Securities Act and such New Omnicom Notes shall have been disposed of pursuant to such Registration Statement, (ii) such New Omnicom Notes may be resold without restriction pursuant to Rule 144 (or any similar provision then in force, but not Rule 144A) under the Securities Act, (iii) such New Omnicom Notes shall have ceased to be outstanding or (iv) the Exchange Offer is consummated (except in the case of New Omnicom Notes which may not be exchanged in the Exchange Offer). Each of the series of New Omnicom Notes may be referred to herein as a “Series of Registrable Securities.”

“Registration Expenses” shall mean any and all expenses incident to performance of or compliance by the Company with this Agreement, including without limitation: (i) all SEC or Financial Industry Regulatory Authority ("FINRA") registration and filing fees, (ii) all fees and expenses incurred in connection with compliance with state securities or blue sky laws, (iii) all expenses of any Persons in preparing or assisting in preparing, word processing, printing and distributing any Registration Statement, any Prospectus, any amendments or supplements thereto, any underwriting agreements, securities sales agreements and other documents relating to the performance of and compliance with this Agreement, (iv) the fees and disbursements of counsel for the Company and of the independent public accountants of the Company, including the expenses of any special audits or “cold comfort” letters required by or incident to such performance and compliance, (v) the fees and expenses of the Trustee, and (vi) the fees and expenses of any special experts retained by the Company in connection with any Registration Statement.

“Registration Statement” shall mean any registration statement of the Company which covers any of the Exchange Securities or Registrable Securities pursuant to the provisions of this Agreement, and all amendments and supplements to any such Registration Statement, including post-effective amendments, in each case including the Prospectus contained therein, all exhibits thereto and all material incorporated or deemed incorporated by reference therein.

“SEC” shall mean the United States Securities and Exchange Commission or any successor agency or government body performing the functions currently performed by the United States Securities and Exchange Commission.

“Securities Act” shall mean the Securities Act of 1933, as amended.

“Securities Exchange Act” shall mean the Securities Exchange Act of 1934, as amended.

“Series of New Omnicom Notes” shall mean each series of New Omnicom Notes.

“Shelf Registration” shall mean a registration effected pursuant to Section 2.2.

“Shelf Registration Statement” shall mean a “shelf” registration statement of the Company pursuant to the provisions of Section 2.2, including an Automatic Shelf Registration Statement, if applicable, which covers all of the Registrable Securities on an appropriate form under Rule 415 under the Securities Act, or any similar rule that may be adopted by the SEC, and all amendments and supplements to such Registration Statement, including post-effective amendments, in each case including the Prospectus contained therein, all exhibits thereto and all material incorporated or deemed incorporated by reference therein.

“Trustee” shall mean the trustee with respect to the Registrable Securities under the Indenture.

“Trust Indenture Act” shall mean the Trust Indenture Act of 1939.

2. Registration Under the Securities Act.

2.1 Exchange Offer. Unless the Exchange Offer would violate applicable law or any applicable interpretation of the staff of the SEC, the Company shall, for the benefit of the Holders, at the Company’s cost, use its commercially reasonable efforts to (A) prepare and not later than 180 calendar days following the Exchange Date, file with the SEC an Exchange Offer Registration Statement on an appropriate form under the Securities Act with respect to a proposed Exchange Offer and the issuance and delivery to the Holders, in exchange for each Series of Registrable Securities, of a like principal amount of the corresponding Series of Exchange Securities, (B) cause the Exchange Offer Registration Statement to be declared effective under the Securities Act within 270 calendar days of the Exchange Date, (C) keep the Exchange Offer Registration Statement effective until the closing of the Exchange Offer and (D) cause the Exchange Offer to be consummated not later than 365 calendar days following the Exchange Date. After the effectiveness of the Exchange Offer Registration Statement, the Company shall promptly commence the Exchange Offer, it being the objective of such Exchange Offer to enable each Holder eligible and electing to exchange Registrable Securities for Exchange Securities (assuming that such Holder (a) is not an Affiliate of the Company, (b) is not a broker-dealer who tendered Old IPG Notes acquired directly from IPG for its own account in exchange for New Omnicom Notes, (c) is acquiring the Exchange Securities in the ordinary course of such Holder’s business and (d) is not engaged in and does not intend to engage in and has no arrangements or understandings with any Person to participate in the distribution of the Exchange Securities) to transfer such Exchange Securities from and after their receipt without any limitations or restrictions under the Securities Act and under state securities or blue sky laws.

In order to participate in the Exchange Offer, each Holder must represent to the Company at the time of the consummation of the Exchange Offer (which representation shall be contained in the letter of transmittal or other document accompanying the Exchange Offer Registration Statement) that it (i) is not an Affiliate of the Company, (ii) is not a broker-dealer who tendered Old IPG Notes acquired directly from IPG for its own account in exchange for New Omnicom Notes, (iii) is acquiring the Exchange Securities in the ordinary course of such Holder’s business and (iv) is not engaged in and does not intend to engage in and has no arrangements or understandings with any Person to participate in the distribution of the Exchange Securities.

In connection with the Exchange Offer, the Company shall:

(a) make available to each Holder a copy of the Prospectus forming part of the Exchange Offer Registration Statement, together with an appropriate letter of transmittal and related documents;

(b) keep the Exchange Offer open for acceptance for a period of not less than 20 business days after the date notice thereof is mailed to the Holders (or longer at the option of the Company or if required by applicable law) (such period referred to herein as the “Exchange Period”);

(c) utilize the services of the Depositary for the Exchange Offer; and

(d) otherwise comply in all material respects with all applicable laws relating to the Exchange Offer.

The Exchange Securities shall be issued under (i) the Indenture or (ii) an indenture identical in all material respects to the Indenture and which, in either case, has been qualified under the Trust Indenture Act. The Indenture or such indenture shall provide that the Exchange Securities and the New Omnicom Notes shall vote and consent together on all matters as one class and that none of the Exchange Securities or the New Omnicom Notes will have the right to vote or consent as a separate class on any matter.

As soon as reasonably practicable after the expiration of the Exchange Offer, the Company shall:

(i) accept for exchange all Registrable Securities duly tendered and not validly withdrawn pursuant to the Exchange Offer in accordance with the terms of the Exchange Offer Registration Statement and the letter of transmittal which shall be an exhibit thereto; (ii) deliver to the Trustee for cancellation all Registrable Securities so accepted for exchange; and

(iii) cause the Trustee promptly to authenticate and deliver Exchange Securities to each Holder of Registrable Securities so accepted for exchange in a principal amount equal to the principal amount of the corresponding Series of Registrable Securities of such Holder so accepted for exchange.

Interest on each Exchange Security will accrue from the last date on which interest was paid on the Registrable Security surrendered in exchange therefor or, if no interest has been paid on the Registrable Security, from the last date on which interest was paid on the corresponding Old IPG Notes exchanged upon consummation of the Private Exchange Offers. The Exchange Offer shall not be subject to any conditions, other than (i) that the Exchange Offer, or the making of any exchange by a Holder, does not violate applicable law or any applicable interpretation of the staff of the SEC, (ii) the due tendering of Registrable Securities in accordance with the Exchange Offer, (iii) that each Holder of Registrable Securities exchanged in the Exchange Offer shall have represented that it (A) is not an Affiliate of the Company, (B) is not a broker-dealer who tendered Old IPG Notes acquired directly from IPG for its own account in exchange for New Omnicom Notes, (C) will acquire the Exchange Securities in the ordinary course of such Holder’s business and (D) is not engaged in and does not intend to engage in and has no arrangements or understandings with any Person to participate in the distribution of the Exchange Securities and shall have made such other representations as may be reasonably necessary under applicable SEC rules, regulations or interpretations to render the use of Form S- 4 or other appropriate form under the Securities Act available and (iv) that no action or proceeding shall have been instituted or threatened in any court or by or before any governmental agency with respect to the Exchange Offer which, in the Company’s judgment, would reasonably be expected to impair the ability of the Company to proceed with the Exchange Offer. The Company will use its commercially reasonable efforts to cause the registrar for each Series of Registrable Securities to furnish the Dealer Managers with the names and addresses of the Holders to whom the Exchange Offer is made, and the Dealer Managers shall have the right to contact such Holders and otherwise facilitate the tender of Registrable Securities in the Exchange Offer.

2.2 Shelf Registration. (i) If, because of any changes in law, SEC rules or regulations or applicable interpretations thereof by the staff of the SEC, the Company determines upon the advice of its counsel that it is not permitted to effect the Exchange Offer as contemplated by Section 2.1, (ii) if for any other reason the Exchange Offer is not consummated within 365 days after the original Exchange Date, or (iii) if a Holder notifies the Company in writing prior to the 20th day following the consummation of the Exchange Offer that it is not permitted by applicable law to participate in the Exchange Offer or participates in the Exchange Offer and does not receive fully tradable Exchange Securities pursuant to the Exchange Offer, then in case of each of clauses (i) through (iii) the Company shall, at its reasonable cost:

(a) As promptly as practicable, but no later than 60 days after being required to do so under Section 2.2, cause to be filed with the SEC, and thereafter shall use its commercially reasonable efforts to cause to become effective as promptly as practicable but no later than 270 days after being required to do so under Section 2.2, a Shelf Registration Statement relating to the offer and sale of the Registrable Securities by the Holders from time to time in accordance with the methods of distribution elected by the Majority Holders participating in the Shelf Registration and set forth in such Shelf Registration Statement; provided, however, that nothing in this Section 2.2(a) shall require the filing of a Shelf Registration Statement prior to the deadline for filing the Exchange Offer Registration Statement set forth in Section 2.1; provided, further, that no Holder shall be entitled to be named as a selling security holder in the Shelf Registration Statement or to use the Prospectus forming a part thereof for resales of Registrable Securities unless such Holder has signed and returned to the Company a notice and questionnaire as distributed by the Company consenting to such Holder’s inclusion in the Prospectus as a selling security holder, evidencing such Holder’s agreement to be bound by the applicable provisions of this Agreement and providing such further information to the Company as the Company may reasonably request.

(b) Use its commercially reasonable efforts to keep the Shelf Registration Statement continuously effective in order to permit the Prospectus forming part thereof to be usable by Holders for a period of one year from the Exchange Date, or for such shorter period that will terminate when all Registrable Securities covered by the Shelf Registration Statement have been sold pursuant to the Shelf Registration Statement or cease to be outstanding or otherwise to be Registrable Securities.

(c) Notwithstanding any other provisions hereof, use its commercially reasonable efforts to ensure that (i) any Shelf Registration Statement and any amendment thereto, at the time each such registration statement or amendment thereto becomes effective, and any Prospectus as of the date thereof forming part thereof and any supplement thereto complies in all material respects with the Securities Act and the rules and regulations thereunder, (ii) any Shelf Registration Statement and any amendment thereto does not, when it becomes effective, contain an untrue statement of a material fact or omit to state a material fact required to be stated therein or necessary to make the statements therein not misleading and (iii) any Prospectus forming part of any Shelf Registration Statement, and any supplement to such Prospectus (as amended or supplemented from time to time) (each, as of the date thereof), does not include an untrue statement of a material fact or omit to state a material fact necessary in order to make the statements, in the light of the circumstances under which they were made, not misleading.

The Company further agrees, if necessary, to supplement or amend the Shelf Registration Statement, as required by Section 3(b), and to furnish to the Holders of Registrable Securities copies of any such supplement or amendment promptly after its being used or filed with the SEC (other than with respect to any such supplement or amendment resulting solely from the incorporation by reference of any report filed under the Securities Exchange Act). In the event that the Exchange Offer is consummated within 365 days after the Exchange Date, the Company shall have no obligation to file a Shelf Registration Statement pursuant to Section 2.2(ii).

2.3 Expenses. The Company shall pay all reasonable Registration Expenses in connection with the registration pursuant to Section 2.1 or 2.2. Each Holder shall pay all underwriting discounts and commissions and transfer taxes, if any, relating to the sale or disposition of such Holder’s Registrable Securities pursuant to the Shelf Registration Statement.

2.4 Effectiveness. An Exchange Offer Registration Statement pursuant to Section 2.1 will not be deemed to have become effective unless it has been declared effective by the SEC or has otherwise become effective under Rule 462 under the Securities Act or any other applicable rule, and a Shelf Registration Statement pursuant to Section 2.2 will not be deemed to have become effective unless it has been declared effective by the SEC or has otherwise become effective under Rule 462 under the Securities Act or any other applicable rule; provided, however, that if, after such Registration Statement has been declared effective or has otherwise become effective, the offering of Registrable Securities pursuant to an Exchange Offer Registration Statement or a Shelf Registration Statement is interfered with by any stop order, injunction or other order or requirement of the SEC or any other governmental agency or court, such Registration Statement will be deemed not to have become effective during the period of such interference, until the offering of Registrable Securities pursuant to such Registration Statement may legally resume.

3. Registration Procedures. In connection with the obligations of the Company with respect to Registration Statements pursuant to Sections 2.1 and 2.2, the Company shall:

(a) prepare and file with the SEC a Registration Statement, within the relevant time period specified in Section 2, on the appropriate form under the Securities Act, which form (i) shall be selected by the Company, (ii) shall, in the case of a Shelf Registration, be available for the sale of the Registrable Securities by the eligible selling Holders thereof, and (iii) shall, at the time of effectiveness, comply as to form in all material respects with the requirements of the applicable form and include or incorporate by reference all financial statements required by the SEC to be filed therewith or incorporated by reference therein, and use its commercially reasonable efforts to cause such Registration Statement to become effective and remain effective in accordance with Section 2;

(b) prepare and file with the SEC such amendments and post-effective amendments to each Registration Statement as may be necessary under applicable law to keep such Registration Statement effective for the applicable period; and cause each Prospectus to be supplemented by any required prospectus supplement, and as so supplemented to be filed pursuant to Rule 424 (or any similar provision then in force) under the Securities Act and comply with the provisions of the Securities Act, the Securities Exchange Act and the rules and regulations thereunder applicable to them with respect to the disposition of all securities covered by each Registration Statement during the applicable period in accordance with the intended method or methods of distribution by the selling Holders thereof (including sales by any Participating Broker-Dealer); provided, however, that nothing contained herein shall imply that the Company is liable for any action or inaction of any Holder, including any Participating Broker-Dealer;

(c) in the case of a Shelf Registration, (i) notify each Holder of Registrable Securities, at least three business days prior to filing, that a Shelf Registration Statement (except in the case of an Automatic Shelf Registration Statement, in which case at least three business days prior to the inclusion of information regarding selling security holders in the Prospectus forming a part of such Automatic Shelf Registration Statement) with respect to the Registrable Securities is being filed and advise such Holders that the distribution of Registrable Securities will be made in accordance with the method selected by the Majority Holders participating in the Shelf Registration; (ii) furnish to each Holder of Registrable Securities, if any, without charge, as many copies of each Prospectus, including each preliminary Prospectus, and any amendment or supplement thereto and such other documents as such Holder or underwriter may reasonably request, including financial statements and schedules and, if the Holder so requests, all exhibits in order to facilitate the public sale or other disposition of the Registrable Securities; and (iii) hereby consent to the use of the Prospectus or any amendment or supplement thereto by each of the selling Holders of Registrable Securities in connection with the offering and sale of the Registrable Securities covered by the Prospectus or any amendment or supplement thereto; (d) in the case of a Shelf Registration, use its commercially reasonable efforts to register or qualify the Registrable Securities under all applicable state securities or “blue sky” laws of such jurisdictions as any Holder of Registrable Securities covered by a Shelf Registration Statement shall reasonably request by the time the Shelf Registration Statement is declared effective by the SEC or otherwise becomes effective, and do any and all other acts and things which may be reasonably necessary or advisable to enable each such Holder to consummate the disposition in each such jurisdiction of such Registrable Securities owned by such Holder; provided, however, that the Company shall not be required to (i) qualify as a foreign corporation or as a dealer in securities in any jurisdiction where it would not otherwise be required to qualify but for this Section 3(d), (ii) take any action which would subject it to general service of process or taxation in any such jurisdiction where it is not then so subject or (iii) make any changes to its certificate of incorporation or by-laws (or other organizational documents) or any agreement between it and holders of its ownership interests;

(e) notify promptly counsel for the Holders and counsel for the Dealer Managers and, with respect to clauses (i), (iii), (iv) and (v) of this paragraph only, each Holder of Registrable Securities under a Shelf Registration or any Participating Broker-Dealer who has notified the Company that it is utilizing the Exchange Offer Registration Statement as provided in paragraph (f) below and, if requested by such Holder or Participating Broker-Dealer, confirm such advice in writing promptly (i) when a Registration Statement (other than an Automatic Shelf Registration Statement) has become effective and when any post-effective amendments and supplements thereto become effective, (ii) of any request by the SEC or any state securities authority for post-effective amendments and supplements to a Registration Statement and Prospectus or for additional information after the Registration Statement has become effective, (iii) of the issuance by the SEC or any state securities authority of any stop order suspending the effectiveness of a Registration Statement or the initiation of any proceedings for that purpose, (iv) of the happening of any event or the discovery of any facts during the period a Shelf Registration Statement is effective that requires any change in the Registration Statement or Prospectus so that, as of such date, the statements therein are not misleading and do not omit to state a material fact required to be stated therein to make the statements therein not misleading (in the case of the Prospectus, in the light of the circumstances under which they were made); provided, however, that such notice need not identify the event that requires such change, and (v) of the receipt by the Company of any notification with respect to the suspension of the qualification of the Registrable Securities or the Exchange Securities, as the case may be, for sale in any jurisdiction or the initiation or threatening of any proceeding for such purpose; (f) in the case of the Exchange Offer Registration Statement (i) include in the Exchange Offer Registration Statement a section entitled “Plan of Distribution” which section shall be reasonably acceptable to the Dealer Managers on behalf of the Participating Broker-Dealers, and which shall contain a summary statement of the positions taken or policies made by the staff of the SEC with respect to the potential “underwriter” status of any broker-dealer that holds Registrable Securities acquired for its own account as a result of market-making activities or other trading activities and that will be the beneficial owner (as defined in Rule 13d-3 under the Securities Exchange Act) of Exchange Securities to be received by such broker-dealer in the Exchange Offer, whether such positions or policies have been publicly disseminated by the staff of the SEC or such positions or policies, in the reasonable judgment of the Dealer Managers on behalf of the Participating Broker-Dealers and their counsel, represent the prevailing views of the staff of the SEC, including a statement that any such broker-dealer who receives Exchange Securities for Registrable Securities pursuant to the Exchange Offer may be deemed a statutory underwriter and must deliver a prospectus meeting the requirements of the Securities Act in connection with any resale of such Exchange Securities, (ii) furnish to each Participating Broker- Dealer who has delivered to the Company the notice referred to in Section 3(e), without charge, as many copies of each Prospectus included in the Exchange Offer Registration Statement, including any preliminary Prospectus, and any amendment or supplement thereto, as such Participating Broker-Dealer may reasonably request, (iii) hereby consent to the use of the Prospectus forming part of the Exchange Offer Registration Statement or any amendment or supplement thereto, by any Person subject to the prospectus delivery requirements of the SEC, including all Participating Broker-Dealers, in connection with the sale or transfer of the Exchange Securities covered by the Prospectus or any amendment or supplement thereto, and (iv) include in the transmittal letter or similar documentation to be executed by an exchange offeree in order to participate in the Exchange Offer (x) the following provision:

“If the exchange offeree is a broker-dealer holding Registrable Securities acquired for its own account as a result of market-making activities or other trading activities, it will deliver a prospectus meeting the requirements of the Securities Act in connection with any resale of Exchange Securities received in respect of such Registrable Securities pursuant to the Exchange Offer;” and (y) a statement to the effect that by a broker-dealer making the acknowledgment described in clause (x) and by delivering a Prospectus in connection with the exchange of Registrable Securities, the broker-dealer will not be deemed to admit that it is an underwriter within the meaning of the Securities Act;

(g) (i) in the case of an Exchange Offer, furnish counsel for the Dealer Managers and (ii) in the case of a Shelf Registration, furnish counsel for the Holders copies of any comment letters received from the SEC or any other request by the SEC or any state securities authority for amendments or supplements to a Registration Statement or Prospectus or for additional information;

(h) make every reasonable effort to obtain the withdrawal of any order suspending the effectiveness of a Registration Statement as soon as practicable;

(i) in the case of a Shelf Registration, furnish to each Holder of Registrable Securities upon request, and each underwriter, if any, without charge, at least one conformed copy of each Registration Statement and any post-effective amendment thereto, including financial statements and schedules (without documents incorporated therein by reference and all exhibits thereto, unless requested); (j) in the case of a Shelf Registration, cooperate with the selling Holders of Registrable Securities to facilitate the timely preparation and delivery of certificates representing Registrable Securities to be sold and not bearing any restrictive legends; and enable such Registrable Securities to be in such denominations (consistent with the provisions of the Indenture) and registered in such names as the selling Holders or the underwriters, if any, may reasonably request at least three business days prior to the closing of any sale of Registrable Securities;

(k) in the case of a Shelf Registration, upon the occurrence of any event or the discovery of any facts, each as contemplated by Section 3(e)(iv), as promptly as practicable after the occurrence of such an event, use its commercially reasonable efforts to prepare a supplement or post-effective amendment to the Registration Statement or the related Prospectus or any document incorporated therein by reference or file any other required document so that, as thereafter delivered to the purchasers of the Registrable Securities or Participating Broker- Dealers, such Prospectus will not contain at the time of such delivery an untrue statement of a material fact or omit to state a material fact necessary to make the statements therein, in the light of the circumstances under which they were made, not misleading; at such time as such public disclosure is otherwise made or the Company determines that such disclosure is not necessary, in each case to correct any misstatement of a material fact or to include any omitted material fact, the Company agrees promptly to notify each Holder of such determination and to furnish each Holder such number of copies of the Prospectus as amended or supplemented, as such Holder may reasonably request;

(l) obtain a CUSIP number for each Series of Exchange Securities not later than the effective date of a Registration Statement, and provide the Trustee with printed certificates for each Series of Exchange Securities or each Series of Registrable Securities, as the case may be, in a form eligible for deposit with the Depositary;

(m) unless the Indenture has been qualified under the Trust Indenture Act, (i) cause the Indenture to be qualified under the Trust Indenture Act in connection with the registration of the Exchange Securities or Registrable Securities, as the case may be, (ii) cooperate with the Trustee and the Holders to effect such changes to the Indenture as may be required for the Indenture to be so qualified in accordance with the terms of the Trust Indenture Act and (iii) execute, and use its commercially reasonable efforts to cause the Trustee to execute, all documents as may be required to effect such changes, and all other forms and documents required to be filed with the SEC to enable the Indenture to be so qualified in a timely manner;

(n) in the case of a Shelf Registration, enter into agreements (including, if requested, an underwriting agreement in customary form containing customary representations, warranties, terms and conditions; provided, that the Company shall not be required to enter into such agreement more than once with respect to each Series of Registrable Securities and may delay entering into such agreement until the consummation of any underwritten public offering of debt securities which the Company may have then undertaken) and take all other customary and appropriate actions in order to expedite or facilitate the disposition of such Registrable Securities and in such connection whether or not an underwriting agreement is entered into and whether or not the registration is an underwritten registration; (o) in the case of a Shelf Registration or if a Prospectus is required to be delivered by any Participating Broker-Dealer in the case of an Exchange Offer, make available for inspection by a representative of the Holders of the Registrable Securities, any underwriters participating in any disposition pursuant to a Shelf Registration Statement, any Participating Broker-Dealer and counsel for the Holders, all relevant financial and other records, pertinent corporate documents and properties of the Company reasonably requested by any such Persons, and use commercially reasonable efforts to have the respective officers, directors, employees, and any other agents of the Company supply all relevant information reasonably requested by any such representative, underwriter, Participating Broker-Dealer or counsel for the Holders in connection with a Registration Statement, in each case, as is customary for similar due diligence investigations; provided, however, that any information that is designated in writing by the Company, in good faith, as confidential or any other information customarily treated as confidential for similar due diligence investigations, shall, at the time of delivery of such information, be kept confidential by the Holders, any underwriter, any Participating Broker-Dealer and any of their respective representatives, unless such disclosure is made in connection with a court proceeding or required by law (but only the portion of such confidential information that is required to be disclosed), or such information becomes available to the public generally or through a third party without an accompanying obligation of confidentiality, provided, further, that prior notice shall be provided as practicable to the Company of the potential disclosure of any information in connection with a court proceeding or required by law to permit the Company to obtain a protective order or take such other action to prevent disclosure of such information;

(p) a reasonable time prior to the filing of any Exchange Offer Registration Statement or Shelf Registration Statement (other than an Automatic Shelf Registration Statement), any Prospectus forming a part thereof or of any other Prospectus covering Registrable Securities, any amendment to an Exchange Offer Registration Statement or Shelf Registration Statement or amendment or supplement to such Prospectus (other than with respect to any such amendment or supplement resulting solely from the incorporation by reference of any report filed under the Securities Exchange Act), provide copies of such document to the Dealer Managers, counsel for the Holders, if any, and make such changes in any Exchange Offer Registration Statement, Shelf Registration Statement, any such Prospectus or amendment or supplement thereto prior to the filing thereof as counsel for the Holders may reasonably request within three business days of being sent a draft thereof and make the representatives of the Company available for discussion of such documents as shall be reasonably requested by the Dealer Managers;

(q) otherwise comply with all applicable rules and regulations of the SEC and make available to its security holders, as soon as reasonably practicable (which may be satisfied by filing with EDGAR), an earnings statement covering at least 12 months which shall satisfy the provisions of Section 11(a) of the Securities Act and Rule 158 thereunder; and

(r) cooperate and assist in any filings required to be made with FINRA.

In the case of a Shelf Registration Statement, the Company may (as a condition to the participation of such Holder and the beneficial owner of Registrable Securities in the Shelf Registration and in addition to any other conditions to such participation set forth in this Agreement) require each Holder of Registrable Securities to furnish to the Company prior to the 30th day following the Company’s filing of such request for information with the Trustee for delivery to the Holders such information regarding the Holder and the proposed distribution by such Holder or beneficial owner of such Registrable Securities as the Company may from time to time reasonably request in writing.

In the case of a Shelf Registration Statement, each Holder agrees that, upon receipt of any notice from the Company of the happening of any event or the discovery of any facts, each of the kind described in Section 3(e)(iv), such Holder will forthwith discontinue disposition of Registrable Securities pursuant to a Registration Statement until such Holder’s receipt of the copies of the supplemented or amended Prospectus contemplated by Section 3(k), and, if so directed by the Company, such Holder will deliver to the Company (at its expense) all copies in such Holder’s possession, other than permanent file copies then in such Holder’s possession, of the Prospectus covering such Registrable Securities current at the time of receipt of such notice.

If any of the Registrable Securities covered by any Shelf Registration Statement are to be sold in an underwritten offering, the underwriter or underwriters and manager or managers that will manage such offering will be selected by the Majority Holders of such Registrable Securities included in such offering and shall be acceptable to the Company. No Holder of Registrable Securities may participate in any underwritten offering hereunder unless such Holder (a) agrees to sell such Holder’s Registrable Securities on the basis provided in any underwriting arrangements approved by the Persons entitled hereunder to approve such arrangements and (b) completes and executes all questionnaires, powers of attorney, indemnities, underwriting agreements and other documents required under the terms of such underwriting arrangements.

4. Indemnification; Contribution.

(a) The Company agrees to indemnify and hold harmless, each Holder (including the Dealer Managers, if applicable, and each Participating Broker-Dealer) and each Person, if any, who controls any Holder within the meaning of Section 15 of the Securities Act or Section 20 of the Securities Exchange Act as follows:

(i) against any and all loss, liability, claim, damage and expense, as incurred, arising out of any untrue statement or alleged untrue statement of a material fact contained in any Registration Statement pursuant to which Registrable Securities were registered under the Securities Act or the omission or alleged omission therefrom of a material fact required to be stated therein or necessary to make the statements therein not misleading, or arising out of any untrue statement or alleged untrue statement of a material fact contained in any Prospectus or the omission or alleged omission therefrom of a material fact necessary in order to make the statements therein, in the light of the circumstances under which they were made, not misleading;

(ii) against any and all loss, liability, claim, damage and expense, as incurred, to the extent of the aggregate amount paid in settlement of any litigation, or any investigation or proceeding by any governmental agency or body, commenced or threatened, or of any claim whatsoever based upon any such untrue statement or omission, or any such alleged untrue statement or omission; provided, that any such settlement is effected with the written consent of the Company; and (iii) against any and all expense, as incurred (including the reasonable and documented fees and disbursements of counsel chosen by any indemnified party), reasonably incurred in investigating, preparing or defending against any litigation, or any investigation or proceeding by any governmental agency or body, commenced or threatened, or any claim whatsoever based upon any such untrue statement or omission, or any such alleged untrue statement or omission, to the extent that any such expense is not paid under subparagraph (i) or (ii) above;

provided, however, that this indemnity agreement shall not apply to any loss, liability, claim, damage or expense to the extent arising out of any untrue statement or omission or alleged untrue statement or omission made in reliance upon and in conformity with written information furnished to the Company by such Holder or any underwriter expressly for use in a Registration Statement or any Prospectus.

(b) Each Holder severally, but not jointly, agrees to indemnify and hold harmless the Company and the other selling Holders, and each of their respective directors and officers, and each Person, if any, who controls the Company or any other selling Holder within the meaning of Section 15 of the Securities Act or Section 20 of the Securities Exchange Act, against any and all loss, liability, claim, damage and expense described in the indemnity contained in Section 4(a), as incurred, but only with respect to untrue statements or omissions, or alleged untrue statements or omissions, made in the Shelf Registration Statement or any Prospectus included therein in reliance upon and in conformity with written information with respect to such Holder furnished to the Company by such Holder expressly for use in the Shelf Registration Statement or such Prospectus.

(c) Each indemnified party shall give notice as promptly as reasonably practicable to each indemnifying party of any action or proceeding commenced against it in respect of which indemnity may be sought hereunder, but failure so to notify an indemnifying party shall not relieve such indemnifying party from any liability hereunder to the extent it is not materially prejudiced as a result thereof and in any event shall not relieve it from any liability which it may have otherwise than on account of this indemnity agreement; the indemnifying party shall assume the defense of such action or proceeding with counsel reasonably satisfactory to such indemnified party, and shall not be liable to such indemnified party under this Section 4 for any legal expenses subsequently incurred by such indemnified party in connection with the defense thereof. An indemnified party may participate at its own expense in the defense of such action; provided, however, that counsel to the indemnified party shall not (except with the written consent of the indemnifying party) also be counsel to the indemnifying party. In no event shall the indemnifying party or parties be liable for the fees and expenses of more than one counsel (in addition to any local counsel) separate from their own counsel for all indemnified parties in connection with any one action or separate but similar or related actions in the same jurisdiction arising out of the same general allegations or circumstances. No indemnifying party shall, without the prior written consent of the indemnified parties, settle or compromise or consent to the entry of any judgment with respect to any litigation, or any investigation or proceeding by any governmental agency or body, commenced or threatened, or any claim whatsoever in respect of which indemnification or contribution could be sought under this Section 4 (whether or not the indemnified parties are actual or potential parties thereto), unless such settlement, compromise or consent (i) includes an unconditional release of each indemnified party from all liability arising out of such litigation, investigation, proceeding or claim and (ii) does not include a statement as to or an admission of fault, culpability or a failure to act by or on behalf of any indemnified party.

(d) If the indemnification provided for in this Section 4 is for any reason unavailable to or insufficient to hold harmless an indemnified party in respect of any losses, liabilities, claims, damages or expenses referred to therein, then each indemnifying party shall contribute to the aggregate amount of such losses, liabilities, claims, damages and expenses incurred by such indemnified party, as incurred, in such proportion as is appropriate to reflect the relative fault of the Company on the one hand and the Holders on the other hand in connection with the statements or omissions which resulted in such losses, liabilities, claims, damages or expenses, and the relative benefit received by the indemnified party, on the one hand, and the indemnifying party, on the other hand, in connection with the Exchange Offer and the Shelf Registration, as well as any other relevant equitable considerations.

The relative fault of the Company on the one hand and the Holders on the other hand shall be determined by reference to, among other things, whether any such untrue or alleged untrue statement of a material fact or omission or alleged omission to state a material fact relates to information supplied by the Company or the Holders and the parties’ relative intent, knowledge, access to information and opportunity to correct or prevent such statement or omission.

The Company and the Holders agree that it would not be just and equitable if contribution pursuant to this Section 4 were determined by pro rata allocation or by any other method of allocation which does not take account of the equitable considerations referred to above in this Section 4. The aggregate amount of losses, liabilities, claims, damages and expenses incurred by an indemnified party and referred to above in this Section 4 shall be deemed to include any legal or other expenses reasonably incurred by such indemnified party in investigating, preparing or defending against any litigation, or any investigation or proceeding by any governmental agency or body, commenced or threatened, or any claim whatsoever based upon any such untrue or alleged untrue statement or omission or alleged omission.

No Person guilty of fraudulent misrepresentation (within the meaning of Section 11(f) of the Securities Act) shall be entitled to contribution from any Person who was not guilty of such fraudulent misrepresentation.

For purposes of this Section 4, each Person, if any, who controls a Holder within the meaning of Section 15 of the Securities Act or Section 20 of the Securities Exchange Act shall have the same rights to contribution as such Holder, and each director of the Company, and each Person, if any, who controls the Company within the meaning of Section 15 of the Securities Act or Section 20 of the Securities Exchange Act shall have the same rights to contribution as the Company.

5. Miscellaneous.

5.1 No Inconsistent Agreements. The Company has not entered into and the Company will not after the date of this Agreement enter into any agreement which is inconsistent with the rights granted to the Holders of Registrable Securities in this Agreement or otherwise conflicts with the provisions hereof. The rights granted to the Holders hereunder do not and will not for the term of this Agreement in any way conflict with the rights granted to the holders of the Company’s other issued and outstanding securities under any such agreements.

5.2 Amendments and Waivers. The provisions of this Agreement, including the provisions of this sentence, may not be amended, modified or supplemented, and waivers or consents to departures from the provisions hereof may not be given unless the Company has obtained the written consent of Holders of at least a majority in aggregate principal amount of the outstanding Registrable Securities affected by such amendment, modification, supplement, waiver or departure.

5.3 Notices. All notices and other communications provided for or permitted hereunder shall be made in writing by hand delivery, registered first-class mail, telex, telecopier, or any courier guaranteeing overnight delivery (a) if to a Holder, at the most current address given by such Holder to the Company by means of a notice given in accordance with the provisions of this Section 5.3, which address initially is the address set forth in the Dealer Manager Agreement with respect to the Dealer Managers; and (b) if to the Company, initially at the Company’s address set forth in the Dealer Manager Agreement, and thereafter at such other address of which notice is given in accordance with the provisions of this Section 5.3.

All such notices and communications shall be deemed to have been duly given: at the time delivered by hand, if personally delivered; two business days after being deposited in the mail, postage prepaid, if mailed; when receipt is acknowledged, if emailed; when receipt is acknowledged, if telecopied; and on the next business day if timely delivered to an air courier guaranteeing overnight delivery.

Copies of all such notices, demands, or other communications shall be concurrently delivered by the Person giving the same to the Trustee under the Indenture, at the address specified in such Indenture.

5.4 Successor and Assigns. This Agreement shall inure to the benefit of and be binding upon the successors, assigns and transferees of each of the parties, including, without limitation and without the need for an express assignment, subsequent Holders; provided, that nothing herein shall be deemed to permit any assignment, transfer or other disposition of Registrable Securities in violation of the terms of the Dealer Manager Agreement, any note or global note representing such Registrable Securities or the Indenture. If any transferee of any Holder shall acquire Registrable Securities, in any manner, whether by operation of law or otherwise, such Registrable Securities shall be held subject to all of the terms of this Agreement, and by taking and holding such Registrable Securities such Person shall be conclusively deemed to have agreed to be bound by and to perform all of the terms and provisions of this Agreement, including the restrictions on resale set forth in this Agreement and, if applicable, the Dealer Manager Agreement, and such person shall be entitled to receive the benefits hereof.

5.5 Third Party Beneficiaries. The Dealer Managers (even if each Dealer Manager is not a Holder of Registrable Securities) shall be a third party beneficiary to the agreements made hereunder by the Company for the benefit of the Holders and shall have the right to enforce such agreements directly to the extent it deems such enforcement necessary or advisable to protect its rights or the rights of Holders hereunder. Each Holder of Registrable Securities shall be a third party beneficiary to the agreements made hereunder between the Company, on the one hand, and the Dealer Managers, on the other hand, and shall have the right to enforce such agreements directly to the extent it deems such enforcement necessary or advisable to protect its rights hereunder.

5.6 Restriction on Resales. Until the expiration of one year after the original issuance of the New Omnicom Notes, the Company will not, and will cause its “affiliates” (as such term is defined in Rule 144(a)(1) under the Securities Act) not to, resell any New Omnicom Notes which are “restricted securities” (as such term is defined under Rule 144(a)(3) under the Securities Act) that have been reacquired by any of them and shall immediately upon any purchase of any such New Omnicom Notes submit such to the Trustee for cancellation.

5.7 Counterparts. This Agreement may be executed in any number of counterparts and by the parties hereto in separate counterparts, each of which when so executed shall be deemed to be an original and all of which taken together shall constitute one and the same agreement.

5.8 Headings. The headings in this Agreement are for convenience of reference only and shall not limit or otherwise affect the meaning hereof.

5.9 GOVERNING LAW. THIS AGREEMENT SHALL BE GOVERNED BY AND CONSTRUED IN ACCORDANCE WITH THE LAW OF THE STATE OF NEW YORK WITHOUT REGARD TO THE PRINCIPLES OF CONFLICT OF LAWS THEREOF.

5.10 Severability. In the event that any one or more of the provisions contained herein, or the application thereof in any circumstance, is held invalid, illegal or unenforceable, the validity, legality and enforceability of any such provision in every other respect and of the remaining provisions contained herein shall not be affected or impaired thereby.

[Signature Pages Follow]

IN WITNESS WHEREOF, the parties have executed this Agreement as of the date first written above.

[Signature Page to Registration Rights Agreement]

Confirmed and accepted as of the date first above written:

[Signature Page to Registration Rights Agreement]

Confirmed and accepted as of the date first above written:

[Signature Page to Registration Rights Agreement]

Confirmed and accepted as of the date first above written:

[Signature Page to Registration Rights Agreement]

Confirmed and accepted as of the date first above written:

[Signature Page to Registration Rights Agreement]

Confirmed and accepted as of the date first above written:

[Signature Page to Registration Rights Agreement]

Confirmed and accepted as of the date first above written:

[Signature Page to Registration Rights Agreement]

Confirmed and accepted as of the date first above written:

[Signature Page to Registration Rights Agreement]

Confirmed and accepted as of the date first above written:

[Signature Page to Registration Rights Agreement]