Exhibit 4.1
                                                               Execution Version

                          THIRD SUPPLEMENTAL INDENTURE

            This THIRD SUPPLEMENTAL INDENTURE (the "Supplemental Indenture")
dated as of November 30, 2004 among OMNICOM GROUP INC., a New York corporation
(the "Company"), OMNICOM CAPITAL INC., a Connecticut corporation ("OCI"),
OMNICOM FINANCE INC., a Delaware corporation ("OFI" and together with the
Company and OCI, the "Issuers"), and JPMORGAN CHASE BANK, N.A., as trustee under
the indenture referred to below (the "Trustee").

                              W I T N E S S E T H:

            WHEREAS, the Issuers and the Trustee have heretofore executed and
delivered to the Trustee an Indenture dated February 7, 2001, as amended by the
First Supplemental Indenture, dated February 13, 2004 (as so amended, the
"Indenture"), providing for the issuance of an aggregate principal amount of up
to $850,000,000 of Liquid Yield Option(TM) Notes due 2031 (the "Securities"),
all of which have been issued and $847,031,000 of which are outstanding on the
date hereof;

            WHEREAS, the Issuers desire (i) to surrender their right to pay
Securityholders who are converting their Securities pursuant to Article 10 of
the Indenture with shares of Common Stock and (ii) to modify the method by which
Contingent Cash Interest is determined;

            WHEREAS, it is in the best interests of the Issuers to surrender
such rights and to modify the method by which Contingent Cash Interest is
determined;

            WHEREAS, Sections 9.02(2) and 9.02(5) of the Indenture provides that
the Issuers and the Trustee may amend or supplement the Indenture only with the
consent of affected Securityholders;

            WHEREAS, all Securityholders have consented to this Supplemental
Indenture and all outstanding Notes shall be bound by it;

            WHEREAS, an Opinion of Counsel has been delivered to the Trustee
under Section 9.02; and

            WHEREAS, pursuant to Sections 9.02 and 9.06 of the Indenture, the
Trustee and the Company are authorized to execute and deliver this Supplemental
Indenture;

            NOW THEREFORE, for good and valuable consideration, the receipt of
which is hereby acknowledged, the Issuers and the Trustee mutually covenant and
agree for the equal and ratable benefit of the holders of the Securities as
follows:

1.    Definitions. All capitalized terms used but not defined herein shall have
the meanings given to such terms set forth in the Indenture.

2.    Amendments. The Indenture be and hereby is amended as follows:

<PAGE>

      2.1   Section 10.02 of the Indenture is hereby amended and restated in its
entirety to read as follows:

"SECTION 10.02 Conversion Procedure.

            To convert a Security a Holder must satisfy the requirements in
paragraph 9 of the Securities. The date on which the Holder satisfies all those
requirements is the conversion date (the "Conversion Date").

            As soon as practicable following the Conversion Date, the Issuers
will deliver, directly or through the Conversion Agent, an amount in cash (the
"Cash Amount") equal to the Issue Price of the Securities surrendered for
conversion. The difference, if positive, between the Conversion Value and the
Issue Price of the Securities surrendered for conversion (the "Premium") may be
satisfied, at the option of the Issuers, exercisable at any time or from time to
time, by an instrument in writing signed by the Issuers, by delivering to a
Converting Holder, in addition to the Cash Amount, either (i) an amount in cash
equal to the Premium or (ii) the number of whole shares of Common Stock equal to
the quotient of (x) the Premium for such Securities divided by (y) the last
reported Sales Price of the Company's Common Stock on the Conversion Date (if
the Conversion Date is not a Business Day, then on the Business Day immediately
preceding the Conversion Date), plus a cash payment for fractional shares
determined pursuant to Section 10.03. At any time after which the Securities
could be converted by action of the Holder, at the written request of a Holder,
the Company will, within five calendar days of receipt of such request, notify
such Holder whether the Premium will be satisfied in cash or Company Common
Stock as aforesaid. Any such notice by the Company will be irrevocable for 60
calendar days (or such longer period as the Company may specify on the notice),
and then may only be revoked after ten additional calendar days notice. All
elections or notices contemplated to be given by the Company in this paragraph
will be made or given by delivery of written notice to the Trustee as herein
provided and to the Holder.

            In the event that the Issuers elect to satisfy the Premium with
Common Shares, the person in whose name the certificate is registered shall be
treated as a stockholder of record on and after the Conversion Date; provided,
however, that no surrender of a Security on any date when the stock transfer
books of the Company shall be closed shall be effective to constitute the person
or persons entitled to receive the shares of Common Stock upon such conversion
as the record holder or holders of such shares of Common Stock on such date, but
such surrender shall be effective to constitute the person or persons entitled
to receive such shares of Common Stock as the record holder or holders thereof
for all purposes at the close of business on the next succeeding day on which
such stock transfer books are open; such conversion shall be at the Conversion
Rate in effect on the date that such Security shall have been surrendered for
conversion, as if the stock transfer books of the Company had not been closed.
Upon conversion of a Security, such person shall no longer be a Holder of such
Security.

            No payment or adjustment will be made for dividends on, or other
distributions with respect to, any Common Stock except as provided in this
Article 10. On conversion of a Security, that portion of accrued Contingent
Additional Principal attributable to the period from the Issue Date of the
Security through the Conversion Date and (except as provided below) accrued
Contingent Cash Interest with respect to the converted Security shall not be
cancelled,


                                      -2-
<PAGE>

extinguished or forfeited, but rather shall be deemed to be paid in full to the
Holder thereof through delivery of the Cash Amount, together with cash or Common
Stock in respect of the Premium, in exchange for the Security being converted
pursuant to the provisions hereof; and the fair market value of such cash or
Common Stock in respect of the Premium shall be treated as delivered, to the
extent thereof, in exchange for Contingent Additional Principal accrued through
the Conversion Date and accrued Contingent Cash Interest, and the Cash Amount
shall be treated as delivered in exchange for the Issue Price of the Security
being converted pursuant to the provisions hereof.

            If the Holder converts more than one Security at the same time, the
Cash Amount, together with the cash or Common Stock in respect of the Premium,
issuable upon the conversion shall be based on the total Principal Amount at
Maturity of the Securities converted.

            If the last day on which a Security may be converted is a Legal
Holiday, the Security may be surrendered on the next succeeding day that is not
a Legal Holiday.

            Upon surrender of a Security that is converted in part, the Issuers
shall execute, and the Trustee shall authenticate and deliver to the Holder, a
new Security in an authorized denomination equal in Principal Amount at Maturity
to the unconverted portion of the Security surrendered."

      2.2   Section 10.05 of the Indenture is hereby amended and restated in its
entirety to read as follows:

"SECTION 10.05 Company to Provide Stock.

            The Company shall, prior to issuance of any Securities under this
Article 10, and from time to time as may be necessary, reserve out of its
authorized but unissued Common Stock a sufficient number of shares of Common
Stock to permit satisfaction of the Premium with Common Stock upon the
conversion of the Securities.

            All shares of Common Stock delivered upon conversion of the
Securities shall be newly issued shares on treasury shares, shall be duly and
validly issued and fully paid and nonassessable and shall be free from
preemptive rights and free of any lien or adverse claim.

      The Company will endeavor promptly to comply with all federal and state
securities laws regulating the offer and delivery of shares of Common Stock upon
conversion of Securities, if any, and will list or cause to have quoted such
shares of Common Stock on each national securities exchange or in the
over-the-counter market or such other market on which the Common Stock is then
listed or quoted."

      2.3   A new subparagraph (d), to read in its entirety as follows, will be
added to the existing Section 10.08 of the Indenture:

SECTION 10.08 Adjustment for Other Distributions.


                                      -3-
<PAGE>

            "(d) if the Company pays any Regular Cash Dividend during any
quarterly fiscal period for which Contingent Cash Interest is payable, the
Conversion Rate will be adjusted as of the record date for such Regular Cash
Dividend based on the following formula:

                          CR' = CRo x     SPo
                                      ------------
                                        SPo - C

      CR0 = the Conversion Rate in effect immediately prior to the record date
            for such Regular Cash Dividend

      CR' = the Conversion Rate in effect immediately after the record date for
            such Regular Cash Dividend; provided that (1) CR' shall not be less
            than 9.09 (except as adjusted pursuant to other provisions of this
            Indenture); and (2) when, if not for clause (1) CR' would be less
            than 9.09, CR0 will be equal to such CR' for purposes of making the
            next quarterly adjustment calculation.

      SP0 = the average of the last reported Sale Prices of the Common Stock for
            the ten consecutive Trading Days prior to the Business Day
            immediately preceding the record date of such Regular Cash Dividend

      C   = the difference of (x) the amount in cash per share paid to holders
            of Common Stock in any quarterly period minus (y) the amount set
            forth for such quarterly fiscal period in Section 5 of the Notes
            divided by 9.09 (appropriately adjusted from time to time for any
            share dividends on, or subdivisions of, the Common Stock)

            Notice of any adjustment to the Conversion Rate as provided in this
Section 10.08(d) need not be given to any Holder unless such adjustment,
together with all prior adjustments pursuant to this Section 10.08(d) for which
notice has not previously been given, would require an increase or decrease of
at least 1% in the Conversion Rate; provided that the Company shall give Holders
annual notice, within 120 days after the end of each fiscal year of the Company
(beginning with the fiscal year ending on December 31, 2006), of all adjustments
made pursuant to this Section 10.08(d) during such fiscal year.

            "Regular Cash Dividends" means quarterly or other periodic cash
dividends on the Company's Common Stock as declared by the Board of Directors as
part of its cash dividend payment practices and that are not designated by the
Board of Directors as extraordinary or special or other nonrecurring dividends.

      2.4   Section 10.09 of the Indenture is hereby amended and restated in its
entirety to read as follows:

"SECTION 10.09 When Adjustment May Be Deferred.

            "Except for adjustments calculated pursuant to Section 10.08(d), no
adjustment in the Conversion Rate need be made unless the adjustment would
require an increase or decrease


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<PAGE>

of at least 1% in the Conversion Rate. Any adjustments that are not made shall
be carried forward and taken into account in any subsequent adjustment. "

      2.5   Section 5 of Exhibit A-1 to the Indenture is hereby amended and
restated in its entirety to read as follows:

            "5. Contingent Cash Interest.

            Subject to the record date provisions specified in this paragraph 5,
the Issuers shall pay, jointly and severally, contingent cash interest
("Contingent Cash Interest") to the Holder of this Security during any six-month
period (each a "Contingent Interest Period") from February 8 to August 7 or from
August 8 to February 7, commencing on or after February 8, 2006, if the average
of the LYON Market Prices for each of the days in the Five-Day Period with
respect to such Contingent Interest Period equals or exceeds 120% of the Issue
Price at Maturity of this Security.

            Contingent Cash Interest, if any, will accrue from the first day of
the applicable six-month period and be payable quarterly on January 31, April
30, July 31 and October 31 (each a "Contingent Interest Payment Date") of the
relevant six-month period to Holders of the Security on the record date, which
will be each April 15, July 15, October 15 and January 15, immediately preceding
each applicable payment date set forth below.

            For any six-month period, the amount of Contingent Cash Interest
payable on any Contingent Interest Payment Date per $1,000 Issue Price thereof
in respect of any Contingent Interest Period shall equal the amounts set forth
below per $1,000 Issue Price for each applicable six-month period.

                             Quarterly                                 Quarterly
Payment Date                  Interest    Payment Date                  Interest
April 30, 2006.............    $1.87      October 31, 2018...........    $3.39
July 31, 2006..............    $1.87      January 31, 2019...........    $3.39
October 31, 2006...........    $1.99      April 30, 2019.............    $3.39
January 31, 2007...........    $1.99      July 31, 2019..............    $3.39
April 30, 2007.............    $1.99      October 31, 2019...........    $3.51
July 31, 2007..............    $1.99      January 31, 2020...........    $3.51
October 31, 2007...........    $2.11      April 30, 2020.............    $3.51
January 31, 2008...........    $2.11      July 31, 2020..............    $3.51
April 30, 2008.............    $2.11      October 31, 2020...........    $3.63
July 31, 2008..............    $2.11      January 31, 2021...........    $3.63
October 31, 2008...........    $2.22      April 30, 2021.............    $3.63
January 31, 2009...........    $2.22      July 31, 2021..............    $3.63
April 30, 2009.............    $2.22      October 31, 2021...........    $3.75
July 31, 2009..............    $2.22      January 31, 2022...........    $3.75
October 31, 2009...........    $2.34      April 30, 2022.............    $3.75
January 31, 2010...........    $2.34      July 31, 2022..............    $3.75
April 30, 2010.............    $2.34      October 31, 2022...........    $3.86
July 31, 2010..............    $2.34      January 31, 2023...........    $3.86
October 31, 2010...........    $2.46      April 30, 2023.............    $3.86
January 31, 2011...........    $2.46      July 31, 2023..............    $3.86
April 30, 2011.............    $2.46      October 31, 2023...........    $3.98
July 31, 2011..............    $2.46      January 31, 2024...........    $3.98
October 31, 2011...........    $2.57      April 30, 2024.............    $3.98


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<PAGE>

January 31, 2012...........    $2.57      July 31, 2024..............    $3.98
April 30, 2012.............    $2.57      October 31, 2024...........    $4.10
July 31, 2012..............    $2.57      January 31, 2025...........    $4.10
October 31, 2012...........    $2.69      April 30, 2025.............    $4.10
January 31, 2013...........    $2.69      July 31, 2025..............    $4.10
April 30, 2013.............    $2.69      October 31, 2025...........    $4.21
July 31, 2013..............    $2.69      January 31, 2026...........    $4.21
October 31, 2013...........    $2.81      April 30, 2026.............    $4.21
January 31, 2014...........    $2.81      July 31, 2026..............    $4.21
April 30, 2014.............    $2.81      October 31, 2026...........    $4.33
July 31, 2014..............    $2.81      January 31, 2027...........    $4.33
October 31, 2014...........    $2.93      April 30, 2027.............    $4.33
January 31, 2015...........    $2.93      July 31, 2027..............    $4.33
April 30, 2015.............    $2.93      October 31, 2027...........    $4.45
July 31, 2015..............    $2.93      January 31, 2028...........    $4.45
October 31, 2015...........    $3.04      April 30, 2028.............    $4.45
January 31, 2016...........    $3.04      July 31, 2028..............    $4.45
April 30, 2016.............    $3.04      October 31, 2028...........    $4.56
July 31, 2016..............    $3.04      January 31, 2029...........    $4.56
October 31, 2016...........    $3.16      April 30, 2029.............    $4.56
January 31, 2017...........    $3.16      July 31, 2029..............    $4.56
April 30, 2017.............    $3.16      October 31, 2029...........    $4.68
July 31, 2017..............    $3.16      January 31, 2030...........    $4.68
October 31, 2017...........    $3.28      April 30, 2030.............    $4.68
January 31, 2018...........    $3.28      July 31, 2030..............    $4.68
April 30, 2018.............    $3.28      October 31, 2030...........    $4.80
July 31, 2018..............    $3.28      January 31, 2031...........    $4.80

            "Five-Day Period" means, with respect to any Contingent Interest
Period, the five trading days ending on the second trading day immediately
preceding the first day of such Contingent Interest Period; provided, however,
if the Company shall have declared a Regular Cash Dividend on its Common Stock
that is payable during such Contingent Interest Period but for which the record
date for determining stockholders entitled thereto precedes the first day of
such Contingent Interest Period, then "Five-Day Period" shall mean, with respect
to such Contingent Interest Period, the five trading days ending on the second
trading day immediately preceding such record date.

            "Regular Cash Dividends" means quarterly or other periodic cash
dividends on the Company's Common Stock as declared by the Board of Directors as
part of its cash dividend payment practices and that are not designated by the
Board of Directors as extraordinary or special or other nonrecurring dividends.

            "LYON Market Price" means, as of any date of determination, the
average of the secondary market bid quotations per $1,000 Principal Amount at
Maturity obtained by the Bid Solicitation Agent for $10 million Principal Amount
at Maturity of Securities at approximately 4:00 p.m., New York City time, on
such determination date from three independent nationally recognized securities
dealers in The City of New York (none of which shall be an Affiliate of the
Issuers) selected by the Issuers; provided, however, if (a) at least three such
bids are not obtained by the Bid Solicitation Agent or (b) in the Issuers'
reasonable judgment, the bid quotations are not indicative of the secondary
market value of the Securities as of such determination date, then the LYON
Market Price for such determination date shall equal (i) the Conversion Rate in
effect


                                      -6-
<PAGE>

as of such determination date multiplied by (ii) the average of the Sale Prices
of the Common Stock for each of the five trading days ending on such
determination date, appropriately adjusted to take into account the occurrence,
during the period commencing on the first of such trading days during such five
trading day period and ending on such determination date, of any event described
in Section 10.06, 10.07 or 10.08 (subject to the conditions set forth in
Sections 10.09 and 10.10) of the Indenture.

            The Issuers will determine every six months, commencing February 8,
2006, whether the conditions to the payment of Contingent Cash Interest have
been satisfied and, if so, the Issuers shall promptly notify the Holders of this
Security of such determination and shall use their reasonable best efforts to
post this information on their web site or, at their option, otherwise publicly
disclose this information.

      2.6   Section 9 of Exhibit A-1 to the Indenture is hereby amended and
restated in its entirety to read as follows:

"9.   Conversion.

            Holders may surrender Securities for conversion only if at least one
of the conditions described in (a) through (d) below is satisfied. In addition,
a Security for which a Holder has delivered a Purchase Notice or a Change in
Control Purchase Notice requiring the Issuers to purchase the Security may be
surrendered for conversion only if such notice is withdrawn in accordance with
the Indenture.

            The initial Conversion Rate is 9.09 shares per $1,000 Issue Price of
a Security, subject to adjustment upon the occurrence of certain events
described in the Indenture. A Holder otherwise entitled to a fractional share
will receive cash in an amount equal to the value of such fractional share based
on the Sale Price on the trading day immediately preceding the Conversion Date.

            The ability to surrender Securities for conversion will expire at
the close of business on February 7, 2031.

(a) Before February 7, 2021, Holders may surrender a Security for conversion
during any calendar quarter, commencing after March 31, 2001 if the average
Conversion Value of the Security for each of the last 20 trading days in the
preceding calendar quarter is greater than or equal to a specified percentage of
the Issue Price; 125% for the quarter ending June 30, 2001, and increasing 5%
per quarter for each quarter thereafter up to a maximum of 220% of the Issue
Price of the Security for the quarter ending June 30, 2006. Thereafter, this
percentage shall remain at 220%. On or after February 7, 2021 Holders may
surrender a Security for conversion during any calendar quarter if the average
of the Conversion Values of the Security for each of the last 20 trading days in
the preceding calendar quarter is greater than or equal to 110% of the Principal
Amount at Maturity of the Security. If either of the foregoing conditions is
satisfied, then the Securities will become and remain convertible at any time
thereafter at the option of the Holder, through maturity.

            On February 7, 2021, if the average of the Conversion Values of the
Security for each of the preceding 20 trading days of a Security is greater than
or equal to 220% of the Issue


                                      -7-
<PAGE>

Price of the Security, then the Security will become and remain convertible at
any time thereafter at the option of the Holder, through maturity.

(b) Holders may also surrender a Security for conversion any time after the
credit rating assigned to the Securities is reduced to Baa3 or lower by Moody's
Investors Service, Inc. or BBB or lower by Standard & Poor's Ratings Services,
even if the credit rating assigned has subsequently been changed to a higher
rating.

(c) A Holder may surrender for conversion a Security with respect to which the
Issuers have mailed a Redemption Notice at any time prior to the close of
business on the second Business Day prior to the Redemption Date, even if it is
not otherwise convertible at that time.

(d) If the Company elects to

            o     distribute to all Holders of Common Stock certain rights
                  entitling them to purchase, for a period expiring within 60
                  days, Common Stock at less than the Sale Price at the time, or

            o     distribute to all Holders of Common Stock assets, debt
                  securities or certain rights to purchase securities of the
                  Company, which distribution has a per share value as
                  determined by the Company's Board of Directors exceeding 15%
                  of the closing price of the Common Stock on the day preceding
                  the declaration date for such distribution,

the Company must notify the Holders of Securities at least 20 days prior to the
Ex-Dividend Date for such distribution. Once the Company has given such notice,
Holders may surrender their Securities for conversion at any time thereafter
until the earlier of the close of business on the Business Day prior to the
Ex-Dividend Date or the Company's announcement that such distribution will not
take place.

            Contingent Cash Interest will not be paid on Securities that are
converted; provided, however that Holders of Securities surrendered for
conversion during the period from the close of business on any record date for
determining an obligation to pay Contingent Cash Interest to the opening of
business on the date on which such Contingent Cash Interest is payable, shall be
entitled to receive such Contingent Cash Interest on the date on which such
Contingent Cash Interest is payable. Except Securities with respect to which the
Issuers have mailed a Notice of Redemption, Securities surrendered for
conversion during such periods must be accompanied by payment of an amount equal
to the Contingent Cash Interest with respect thereto that the registered Holder
is to receive.

            The Conversion Rate will not be adjusted for accrued Contingent
Additional Principal, if any, or Contingent Cash Interest, if any. As soon as
practicable following the Conversion Date, the Issuers will deliver through the
Conversion Agent, the Cash Amount, together with cash or a certificate for the
number of full shares of Common Stock into which the Premium of any Security is
converted and any cash payment for fractional shares. Delivery to the Holder of
the Cash Amount, together with such cash or shares of Common Stock deliverable


                                      -8-
<PAGE>

in connection with the Premium, will be deemed to satisfy the Issuers'
obligation to pay the Principal Amount at Maturity of and any accrued Contingent
Principal Amount on the Security.

            Subject to the provisions of this paragraph 9 and notwithstanding
the fact that any other condition to conversion has not been satisfied, in the
event the Company is a party to a consolidation, merger or binding share
exchange pursuant to which the Common Stock would be converted into cash,
securities or other property as set forth in Section 10.14 of the Indenture, the
Securities may be surrendered for conversion at any time from and after the date
which is 15 days prior to the date the Company announces the anticipated
effective time until 15 days after the actual effective date of such
transaction, and at the effective time of such transaction the right to convert
a Security into Common Stock will be deemed to have changed into a right to
convert it into the kind and amount of cash, securities or other property which
the Holder would have received if the Holder had converted its Security
immediately prior to the transaction. If the transaction also constitutes a
Change in Control, the Holder will be able to require the Company to purchase
all or a portion of its Securities as described under paragraph 7 herein.

            To convert a Security, a Holder must (1) complete and manually sign
the conversion notice below (or complete and manually sign a facsimile of such
notice) and deliver such notice to the Conversion Agent, (2) surrender the
Security to the Conversion Agent, (3) furnish appropriate endorsements and
transfer documents if required by the Conversion Agent, the Issuers or the
Trustee and (4) pay any transfer or similar tax, if required. The "Conversion
Date" as used herein refers to the date on which all of the foregoing
requirements have been satisfied.

            A Holder may convert a portion of a Security if the Issue Price of
such portion is $1,000 or an integral multiple of $1,000. No payment or
adjustment will be made for dividends on the Common Stock except as provided in
the Indenture. On conversion of a Security, that portion of accrued Contingent
Additional Principal attributable to the period from the Issue Date through the
Conversion Date and (except as provided above) accrued Contingent Cash Interest
with respect to the converted Security shall not be cancelled, extinguished or
forfeited, but rather shall be deemed to be paid in full to the Holder thereof
through the delivery of the Cash Amount, together with cash or Common Stock in
respect of the Premium, in exchange for the Security being converted pursuant to
the terms hereof; and the fair market value of such cash or Common Stock in
respect of the Premium, shall be treated as delivered to the extent thereof, in
exchange for Contingent Additional Principal accrued through the Conversion Date
and accrued Contingent Cash Interest, and the Cash Amount shall be treated as
delivered in exchange for the Issue Price of the Security being converted
pursuant to the provisions hereof.

            The Conversion Rate will be adjusted as provided in Article 10 of
the Indenture. However, no adjustment need be made if Securityholders may
participate in the transaction or in certain other cases. The Company from time
to time may voluntarily increase the Conversion Rate."

3.   Separability Clause. In case any provision in this Supplemental Indenture
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.


                                      -9-
<PAGE>

4.   Modification, Amendment and Waiver. The provisions of this Supplemental
Indenture may not be amended, supplemented, modified or waived except by a
execution of a Supplemental Indenture executed by the Issuers, the Company and,
to the extent such amendment, supplement or waiver limits or impairs the rights
of any Securityholder, by such Securityholder. Any such amendment shall comply
with Article 9 of the Indenture. Until an amendment, waiver or other action by
Securityholders becomes effective, a consent thereto by a Securityholder of a
Security hereunder is a continuing consent by the Securityholder and every
subsequent Securityholder of that Security or portion of the Security that
evidences the same obligation as the consenting Securityholder's Security, even
if notation of the consent, waiver or action is not made on the Security.
However, any such Securityholder or subsequent Securityholder may revoke the
consent, waiver or action as to such Securityholder'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 Securityholder.

5.   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. In the event of a conflict between the terms and
conditions of the Indenture and the terms and conditions of this Supplemental
Indenture, then the terms and conditions of this Supplemental Indenture shall
prevail. This 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.

6.   Trust Indenture Acts Controls. If any provision of this Supplemental
Indenture limits, qualifies or conflicts with any provision of the Trust
Indenture Act of 1939, as amended ("TIA"), that is required under the TIA to be
part of and govern any provision of this Supplemental Indenture, the provision
of the TIA shall control. If any provision of this 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 Supplemental Indenture, as the case may
be.

7.   Governing Law. THIS SUPPLEMENTAL INDENTURE SHALL BE GOVERNED BY AND
CONSTRUED IN ACCORDANCE WITH THE LAWS OF THE STATE OF NEW YORK, AS APPLIED TO
CONTRACTS MADE AND PERFORMED WITHIN THE STATE OF NEW YORK WITHOUT GIVING EFFECT
TO THE PRINCIPLES OF CONFLICTS OF LAW.

8.   Trustee Makes No Representation. The statements herein are deemed to be
those of the Company, OCI or OFI, as applicable. The Trustee makes no
representation as to the validity or sufficiency of this Supplemental Indenture.

9.   Multiple Originals. The parties may sign any number of copies of this
Supplemental Indenture. Each signed copy shall be an original, but all of them
together represent the same agreement. One signed copy is enough to prove this
Supplemental Indenture.


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<PAGE>

10.   Effect of Headings. The Section headings herein are for convenience only
and shall not effect the construction thereof.

11.   Notices. Any request, demand, authorization, notice, waiver, consent or
communication to any of the parties shall be made as set forth in Section 12.02
of the Indenture, as said Section may be amended hereby.

12.   Successors. All agreements of each of the Company, OCI and OFI in respect
of this Supplemental Indenture shall bind its successor.

                            [Signature page follows]


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<PAGE>

      IN WITNESS WHEREOF, this Supplemental Indenture has been duly executed by
the Company, OCI and the Trustee as of the date first written above.

                                          OMNICOM GROUP INC.

                                          By: /s/ RANDALL J. WEISENBURGER
                                              ----------------------------------
                                              Name:  Randall J. Weisenburger
                                              Title: Executive Vice President
                                                     and Chief Financial Officer

                                          OMNICOM CAPITAL INC.

                                          By: /s/ MICHAEL J. O'BRIEN
                                              ----------------------------------
                                              Name:  Michael J. O'Brien
                                              Title: Secretary

                                          OMNICOM FINANCE INC.

                                          By: /s/ RANDALL J. WEISENBURGER
                                              ----------------------------------
                                              Name:  Randall J. Weisenburger
                                              Title: Chief Executive Officer

                                          JPMORGAN CHASE BANK, N.A., as Trustee

                                          By: /s/ CAROL NG
                                              ----------------------------------
                                              Name:  Carol Ng
                                              Title: Vice President


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