Prospectus Supplement filed under Rule 424(b)(3)
                                                      Registration No. 333-84573

                              Prospectus Supplement
                                Dated May 5, 2000

     The Prospectus dated August 13, 1999 relating to the offer for resale of up
to $361,000,000 aggregate principal amount of The Interpublic Group of
Companies, Inc.'s 1.87% Convertible Subordinated Notes due 2006, and such shares
of common stock as may be issued upon conversion of the notes, is hereby
supplemented to include the following information in the "Selling
Securityholders" table in the Prospectus Supplement dated August 13, 1999:


                                                            Principal Amount
                                                              of Registered
                Selling Securityholders                           Notes
- ---------------------------------------------------------  ---------------------

Van Kampen Harbor Fund(1).................................      $2,530,000
Van Kampen Convertible Securities Fund(1).................         470,000
                                                                   -------

     Total of Above.......................................      $3,000,000
                                                                ==========
- --------------------------------------------------------------------------------

(1)  Morgan Stanley & Co. Incorporated, an affiliate of Van Kampen Harbor Fund
     and Van Kampen Convertible Securities Fund, was an initial purchaser of the
     1.87% Convertible Subordinated Notes due 2006, when the notes were
     originally sold in a private placement.