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





                              Prospectus Supplement
                             Dated December 3, 1999

     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:


     The "Selling Securityholders" table in the Prospectus, as supplemented, is
amended so that the principal amount of registered notes held by Morgan Stanley
Dean Witter1 is decreased from $5,000,000 to $500,000.

     The "Selling Securityholders" table in the Prospectus, as supplemented, is
amended so that the principal amount of registered notes held by PIMCO Total
Return Fund is decreased from $5,000,000 to $3,000,000.



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1    Morgan Stanley & Co. Incorporated, an affiliate of Morgan Stanley Dean
     Witter, was an initial purchaser of the 1.87% Convertible Subordinated
     Notes due 2006, when the notes were originally sold in a private placement.
     In addition, Morgan Stanley & Co. Incorporated was also an initial
     purchaser of Interpublic's 1.80% Convertible Subordinated Notes due 2004
     when those notes were originally sold in a private placement. As of
     December 3, 1999, Morgan Stanley Dean Witter held $179,000 of Interpublic's
     1.80% Convertible Subordinated Notes due 2004.