Prospectus Supplement filed under Rule 424(b)(3) Registration No. 333-45569 Prospectus Supplement The Prospectus dated February 4, 1998 relating to the offer for resale of up to $250,000,000 aggregate principal amount of The Interpublic Group of Companies, Inc.'s 1.80% Convertible Subordinated Notes due September 16, 2004 is hereby supplemented to include the following information in the "Selling Securityholders" table in the Prospectus Supplement dated February 25, 1998: Principal Amount of Registered Selling Holders Notes - ------------------------------------------------- ---------------- American Investors Life Insurance Company, Inc... $3,000,000 Carex A.V.V...................................... 150,000 Employers Reinsurance Corp....................... 3,000,000 General Motors Investment Management Corp........ 15,000,000 Motors Insurance Corp............................ 2,000,000 Regence Blue Cross/Blue Shield of Idaho.......... 20,000 Regence Blue Cross/Blue Shield of Oregon......... 498,000 Regence Blue Cross/Blue Shield of Utah........... 132,000 Regence Blue Cross/Blue Shield of Washington..... 75,000 Sorex A.V.V...................................... 100,000 - ------------------------------------------------- ---------------- Total of Above................................... $23,975,000 ================ This Prospectus Supplement is dated August 18, 1998.