FILED PURSUANT TO RULE 424(B)(3)
                                                     REGISTRATION NO. 333-108611

                                  $600,000,000

                               OMNICOM GROUP INC.
                              OMNICOM CAPITAL INC.
                              OMNICOM FINANCE INC.
               Zero Coupon Zero Yield Convertible Notes Due 2033

                  PROSPECTUS SUPPLEMENT DATED DECEMBER 15, 2004
                      TO PROSPECTUS DATED NOVEMBER 5, 2003

      The selling securityholders table on pages 33-34 of the prospectus is
hereby further amended to update the information to include the following entity
as a selling securityholder in the prospectus and to list its total amount of
Zero Coupon Zero Yield Convertible Notes due 2033:



                                                        AGGREGATE
                                                     PRINCIPAL AMOUNT                           COMMON            COMMON
                                                       OF NOTES AT         PERCENTAGE           STOCK             STOCK
                                                      MATURITY THAT         OF NOTES        OWNED PRIOR TO      REGISTERED
NAME                                                   MAY BE SOLD         OUTSTANDING        CONVERSION         HEREBY(1)
----                                                 ----------------      -----------      --------------      ----------
                                                                                                       
State of Mississippi Health Care Trust Fund             $825,000              *                  --                8,009


----------
*     Less than 1%

(1)   Assumes conversion of all the holder's notes at a conversion rate of
      9.7087 shares of common stock per $1,000 principal amount at maturity of
      the notes. Notes in the aggregate principal amount of $590,780,000
      consented to receive cash for the initial principal amount and cash or
      shares representing the difference between the conversion value and the
      initial principal amount of the notes. This conversion rate will be
      subject to adjustment as described under "Description of the Notes --
      Conversion Rights." As a result, the amount of common stock issuable or
      cash amount payable upon conversion of the notes may increase or decrease
      in the future.

      The preceding table has been prepared based upon information furnished to
us by the selling securityholders named in the table. From time to time,
additional information concerning ownership of the notes and common stock may be
known by certain holders thereof not named in the preceding table, with whom we
believe we have no affiliation. Information about the selling securityholders
may change over time. Any changed information will be set forth in supplements
of amendments to this prospectus.