Exhibit 4.2


 


OMNICOM GROUP INC.


 


as Issuer


FIRST SUPPLEMENTAL INDENTURE


Dated as of February 21, 2020


DEUTSCHE BANK TRUST COMPANY AMERICAS


as Trustee


Debt Securities




     


    


    

First Supplemental Indenture dated
as of February 21, 2020 (the “First 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 and sale of up
to $600,000,000 aggregate principal amount of a Series of the Issuer’s 2.450% Senior Notes due 2030 (the “Securities”)
have been authorized by the board of directors of the Issuer;


WHEREAS, the Issuer desires to issue
and sell $600,000,000 aggregate principal amount of the Securities on the date hereof;


WHEREAS, the Issuer desires to enter
into this First 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


NOW,
THEREFORE, THIS FIRST 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 First Supplemental Indenture constitutes
an integral part of the Indenture. In the event of inconsistencies between the Indenture and this First Supplemental Indenture,
the terms hereof shall govern.


Section 1.2.             
Definitions.


(a)       All
of the terms used in this First 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 First Supplemental
Indenture and the Securities, the following terms have the meanings set forth in this Section:


 


“Below Investment Grade Rating Event”
occurs if both the rating on the 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




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rating of such 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:


 


		(1)	the sale, transfer, conveyance or other disposition (other than by way of merger or consolidation), in one or a series of related
transactions, of all or substantially all of the assets of the Issuer and its Subsidiaries taken as a whole to any “person”
(as that term is used in Section 13(d)(3) of the Exchange Act) other than to the Issuer or one of its Subsidiaries;



 


		(2)	the consummation of any transaction (including without limitation, any merger or consolidation) the result of which is that
any “person” (as that term is used in Section 13(d)(3) of the Exchange Act), other than the Issuer or one of its wholly
owned Subsidiaries, becomes the “beneficial owner” (as defined in Rules 13d-3 and 13d-5 under the Exchange Act),
directly or indirectly, of more than 50% of the then outstanding shares of the Issuer’s Voting Stock, measured by voting
power rather than number of shares; or



 


		(3)	the adoption of a plan relating to the liquidation or dissolution of the Issuer.



 


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 First Supplemental Indenture.  


 


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


 


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



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


 


“Comparable Treasury Issue”
means the United States Treasury security selected by the Reference Treasury Dealer as having a maturity comparable to the remaining
term of the


Securities (assuming the Securities matured on the par call date),
that would be utilized, at the time of selection and in accordance with customary financial practice, in pricing new issues of
corporate debt securities of comparable maturity to the remaining term of the Securities (assuming the Securities matured on the
par call date).


 


“Comparable Treasury Price”
means, with respect to any redemption date, the Reference Treasury Dealer Quotations for that redemption date.


 


“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.


“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




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other similar agreements.


 


“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 Securities
or fails to make a rating of such 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.


 


“par call date” has the meaning
specified in Section 3.1 of this First Supplemental Indenture.


 


“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.


 


“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 Securities or fails to make a
rating of the 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.


 


“Reference Treasury Dealer”
means each of any three primary U.S. Government securities dealer selected by the Issuer, and their respective successors.


 


“Reference Treasury Dealer Quotations”
means, with respect to the Reference Treasury Dealer and any redemption date, the average, as determined by the Issuer, of the
bid and asked prices for the Comparable Treasury Issue (expressed in each case as a percentage of its principal




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amount) quoted in writing to the Issuer by the Reference Treasury
Dealer at 3:30 p.m., New York City time, on the third business day preceding that redemption date.


 


“Remaining Scheduled Payments”
means the remaining scheduled payments of principal of and interest on the Securities that but for the redemption would be due
after the related redemption date through the par call date, assuming the Securities matured on the par call date, not including
any portion of such interest payment accrued as of such redemption date. If that redemption date is not an interest payment date
with respect to the Securities, the amount of the next succeeding scheduled interest payment on the Securities will be reduced
by the amount of interest accrued on the Securities to such redemption date.


 


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


 


“Treasury Rate” means, with
respect to any redemption date, the rate per annum equal to the semiannual equivalent yield to maturity (computed as of the third
business day immediately preceding that redemption date) of the Comparable Treasury Issue, assuming a price for the Comparable
Treasury Issue (expressed as a percentage of its principal amount) equal to the Comparable Treasury Price for that redemption date.


 


“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


 


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, the title of the Securities to be issued as a Series of Securities under the Indenture shall be the “2.450%
Senior Notes due 2030”;


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 99.656% 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 First Supplemental
Indenture initially shall be limited to $600,000,000;


2.1.4. Pursuant to Section 2.2.4 of
the Indenture, 100% of the Securities shall be payable on April 30, 2030;




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2.1.5. Pursuant to Section 2.2.5 of
the Indenture, the Securities shall bear interest at a rate equal to 2.450% per annum; interest on the Securities shall accrue
from February 21, 2020 until the principal thereof is paid or duly provided for; interest on the Securities shall be payable semi-annually
in arrears in cash on April 30 and October 30 of each year, commencing on October 30, 2020 to Holders of record on April 15 and
October 15 (whether or not a Business Day) 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 February 21, 2020) 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 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 First 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, the form of which is attached hereto as Exhibit A;


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 First 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 First 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. Pursuant to Section 2.2.11 of the Indenture,
the Securities shall be issued as Global Securities;


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 First 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 or except for first payment of interest following the issue date of such additional Securities).
Any such additional Securities




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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.


 


ARTICLE
THREE


ADDITIONAL
REDEMPTION PROVISION


Section 3.1.             
Optional Redemption.


Prior to January 30, 2030 (“par call date”),
the Securities shall be redeemable, as a whole or in part, at the Issuer’s option, at any time or from time to time, upon
mailed notice (or electronic notice, as applicable) to the registered address of each Holder of Securities at least 15 days but
not more than 60 days prior to the redemption. The redemption price shall be equal to the greater of (1) 100% of the principal
amount of the Securities to be redeemed and (2) the sum of the present values of the Remaining Scheduled Payments on the Securities
discounted to the date of redemption, on a semi-annual basis (assuming a 360-day year consisting of twelve 30-day months), at a
rate equal to the sum of the applicable Treasury Rate plus 15 basis points, plus accrued and unpaid interest thereon, if any, to,
but excluding, the redemption date.


 


On or after the par call date, the Securities
shall be redeemable, as a whole or in part, at the Issuer’s option, at any time or from time to time, upon mailed notice
(or electronic notice, as applicable) to the registered address of each Holder of Securities at least 15 days but not more than
60 days prior to the redemption at a redemption price of 100% of the principal amount of the Securities, plus accrued and unpaid
interest thereon, if any, to, but excluding, the redemption date.


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) 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.


 


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 Securities pursuant to Section 3.1 of this First Supplemental Indenture,
each Holder of 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 on the relevant record date to receive interest due on the relevant interest payment date.


 




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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 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
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 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 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 the Securities by virtue of any such compliance.


 


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


		(a)	accept for payment all Securities or portions of Securities properly tendered and not withdrawn pursuant to the Change of Control
Offer;



 


		(b)	deposit with the Paying Agent an amount equal to the Change of Control Purchase Price in respect of all Securities or portions
of Securities properly tendered and not withdrawn; and



 


		(c)	deliver or cause to be delivered to the Trustee the Securities properly accepted together with an Officer’s Certificate
stating the aggregate principal amount of Securities or portions of Securities being repurchased.



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:




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(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 February 19, 2020;


(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 and provided further that
the aggregate principal amount of such Debt shall not exceed $50,000,000 at any time outstanding;


(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




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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 $500,000,000 (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 First 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 (iv) 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 First 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.



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Section 6.2             
Governing Law.


THIS
FIRST 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
First 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 First 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 First
Supplemental Indenture or in the Securities 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 First 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 a 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 the Security. However, any such Holder or subsequent
Holder may revoke the consent, waiver or action as to such Holder’s Security or portion of the 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.


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




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Section 6.8.             
Trust Indenture Acts
Controls.


If any provision of this First 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 First Supplemental Indenture, the provision of the
TIA shall control. If any provision of this First 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 First 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 First 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 First Supplemental Indenture,
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, THE SECURITIES, THE TRANSACTIONS CONTEMPLATED HEREBY AND THEREBY
OR ANY OTHER DOCUMENT EXECUTED IN CONNECTION HEREWITH OR THEREWITH.


 


[Signatures pages follow]




    -13-


    


    

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


	 	OMNICOM GROUP INC.


	 
	 	 	 
	 	By:	
 /s/ Philip J. Angelastro
	 
	 	 	Name: 	Philip J. Angelastro	 
	 	 	Title: 	Executive Vice President and

 Chief Financial Officer	 
	 	 	 	 




     


    


    

	 	DEUTSCHE BANK TRUST COMPANY

 AMERICAS, as Trustee


	 
	 	 	 
	 	By:	
 /s/ Bridgette Casasnovas
	 
	 	 	Name: 	Bridgette Casasnovas	 
	 	 	Title: 	Vice President	 
	 	 	 	 
	 	 	 	 
	 	By:	
 /s/ Robert S. Peschler
	 
	 	 	Name: 	Robert S. Peschler	 
	 	 	Title: 	Vice President	 
	 	 	 	 




     


    


    

Exhibit A


FORM OF GLOBAL SECURITY FOR THE 2.450%
SENIOR NOTES DUE 2030


THIS GLOBAL SECURITY IS HELD BY THE DEPOSITORY
(AS DEFINED IN THE INDENTURE GOVERNING THIS SECURITY) OR ITS NOMINEE IN CUSTODY FOR THE BENEFIT OF THE BENEFICIAL OWNERS HEREOF,
AND IS NOT TRANSFERABLE TO ANY PERSON UNDER ANY CIRCUMSTANCES EXCEPT THAT (I) THE TRUSTEE MAY MAKE ANY SUCH NOTATIONS HEREON AS
MAY BE REQUIRED PURSUANT TO THE INDENTURE, (II) THIS GLOBAL SECURITY MAY BE EXCHANGED IN WHOLE BUT NOT IN PART PURSUANT TO SECTION
2.7 OF THE INDENTURE, (III) THIS GLOBAL SECURITY MAY BE DELIVERED TO THE TRUSTEE FOR CANCELLATION PURSUANT TO THE INDENTURE AND
(IV) THIS GLOBAL SECURITY MAY BE TRANSFERRED TO A SUCCESSOR DEPOSITORY WITH THE PRIOR WRITTEN CONSENT OF THE ISSUER.


UNLESS AND UNTIL IT IS EXCHANGED IN WHOLE
OR IN PART FOR SECURITIES IN DEFINITIVE FORM, THIS SECURITY MAY NOT BE TRANSFERRED EXCEPT AS A WHOLE BY THE DEPOSITORY TO A NOMINEE
OF THE DEPOSITORY OR BY A NOMINEE OF THE DEPOSITORY TO THE DEPOSITORY OR TO ANOTHER NOMINEE OF THE DEPOSITORY OR BY THE DEPOSITORY
OR ANY SUCH NOMINEE TO A SUCCESSOR DEPOSITORY OR A NOMINEE OF SUCH SUCCESSOR DEPOSITORY. UNLESS THIS GLOBAL SECURITY IS PRESENTED
BY AN AUTHORIZED REPRESENTATIVE OF THE DEPOSITORY TO THE ISSUER OR ITS AGENT FOR REGISTRATION OF TRANSFER, EXCHANGE OR PAYMENT,
AND ANY SECURITY ISSUED IS REGISTERED IN THE NAME OF ANY ENTITY AS MAY BE REQUESTED BY AN AUTHORIZED REPRESENTATIVE OF THE DEPOSITORY
(AND ANY PAYMENT IS MADE TO SUCH ENTITY AS MAY BE REQUESTED BY AN AUTHORIZED REPRESENTATIVE OF THE DEPOSITORY), ANY TRANSFER, PLEDGE
OR OTHER USE HEREOF FOR VALUE OR OTHERWISE BY OR TO ANY PERSON IS WRONGFUL INASMUCH AS THE REGISTERED OWNER HEREOF HAS AN INTEREST
HEREIN.




     


    


    

2.450% Senior Notes
due 2030


ISIN: US681919BB11


CUSIP No. 681919 BB1


$


No.


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 April 30, 2030 and to pay interest thereon from
February 21, 2020 or from the most recent interest payment date to which interest has been paid or duly provided for, semi-annually
on April 30 and October 30 in each year, commencing October 30, 2020, at the rate of 2.450% 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 April 15 or October 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.




     1


    


    

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


	Dated:	OMNICOM GROUP INC.	 
	 	 	 
	 	By:		 
	 	 	Name:	 	 
	 	 	Title:	 	 
	 	 	 	 	 
	 	 	 	 	 
	 	By:		 
	 	 	Name:	 	 
	 	 	Title:	 	 





 



     


    


    

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


	 	Deutsche Bank Trust Company Americas, as Trustee
	 	 
	 	By:	 
	 	 	Authorized Signatory


 


Dated:




     


    


    

Reverse of Security


OMNICOM GROUP INC.


2.450% Senior Notes due 2030


This Security is one of a duly authorized
issue of securities of the Issuer, designated as its 2.450% 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 First Supplemental Indenture dated as of February 21, 2020,
between the Issuer and the Trustee (the “First 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 $600,000,000. 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 January 30, 2030 (the “par call
date”), the Securities shall be redeemable, as a whole or in part, at the Issuer’s option, at any time or from time
to time, upon mailed notice (or electronic notice, as applicable) to the registered address of each Holder of Securities at least
15 days but not more than 60 days prior to the redemption. The redemption price shall be equal to the greater of (1) 100% of the
principal amount of the Securities to be redeemed and (2) the sum of the present values of the Remaining Scheduled Payments on
the Securities discounted to the date of redemption, on a semi-annual basis (assuming a 360-day year consisting of twelve 30-day
months), at a rate equal to the sum of the applicable Treasury Rate plus 15 basis points, plus accrued and unpaid interest thereon,
if any, to, but excluding, the redemption date.


 


On or after the par call date, the Securities
shall be redeemable, as a whole or in part, at the Issuer’s option, at any time or from time to time, upon mailed notice
(or electronic notice, as applicable) to the registered address of each Holder of Securities at least 15 days but not more than
60 days prior to the redemption at a redemption price of 100% of the principal amount of such Securities, plus accrued and unpaid
interest thereon, if any, to, but excluding, the redemption date.


“Comparable Treasury Issue”
means the United States Treasury security selected by the Reference Treasury Dealer as having a maturity comparable to the remaining
term of the




     


    


    

notes (assuming the notes matured on the par call date), that would
be utilized, at the time of


selection and in accordance with customary financial practice, in
pricing new issues of corporate debt securities of comparable maturity to the remaining term of the notes (assuming the notes matured
on the par call date).


 


“Comparable Treasury Price”
means, with respect to any redemption date, the Reference Treasury Dealer Quotations for that redemption date.


 


“Reference Treasury Dealer”
means each of any three primary U.S. Government securities dealer selected by the Issuer, and their respective successors.


 


“Reference Treasury Dealer Quotations”
means, with respect to the Reference Treasury Dealer and any redemption date, the average, as determined by the Issuer, of the
bid and asked prices for the Comparable Treasury Issue (expressed in each case as a percentage of its principal amount) quoted
in writing to the Issuer by the Reference Treasury Dealer at 3:30 p.m., New York City time, on the third business day preceding
that redemption date.


 


“Remaining Scheduled Payments”
means the remaining scheduled payments of principal of and interest on the Securities that but for the redemption would be due
after the related redemption date through the par call date, assuming the Securities matured on the par call date, not including
any portion of such interest payment accrued as of such redemption date. If that redemption date is not an interest payment date
with respect to the Securities, the amount of the next succeeding scheduled interest payment on the Securities will be reduced
by the amount of interest accrued on the Securities to such redemption date.


 


“Treasury Rate” means, with
respect to any redemption date, the rate per annum equal to the semiannual equivalent yield to maturity (computed as of the third
business day immediately preceding that redemption date) of the Comparable Treasury Issue, assuming a price for the Comparable
Treasury Issue (expressed as a percentage of its principal amount) equal to the Comparable Treasury Price for that redemption date.


 


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) 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 of such Series 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 First 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 security Registrar duly executed by, the Holder hereof or his 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.