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 - --------------------------------------------- ---------------- South Dakota Retirement System............... $500,000 - --------------------------------------------- ---------------- Total of Above............................... $500,000 ================ This Prospectus Supplement is dated May 26, 1998.