SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K Current Report Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): March 4, 1998 OMNICOM GROUP INC. (Exact name of registrant as specified in its charter) NEW YORK (State or other jurisdiction of incorporation) 1-10551 13-1514814 (Commission File Number) (I.R.S. Employer Identification No.) 437 Madison Avenue New York, New York 10022 (Address of principal executive offices) Registrant's Telephone Number, Including Area Code): (212) 415-3600 Item 5. Other Events The exhibits listed in the Index to Exhibits under Item 7 below are filed for purpose of incorporating them into Omnicom Group Inc.'s Registration Statement on Form S-3 declared effective February 24, 1998 (File No. 333-46303) (the "Registration Statement"). Item 7. Financial Statements and Exhibits. (c) The exhibits accompanying this report are listed in the Index to Exhibits below and are hereby incorporated as part of Item 16 of the Registration Statement. -2- SIGNATURES Pursuant to the requirements of the Securities Exchange Act of 1934, the registrant has duly caused this report to be signed on its behalf by the undersigned hereunto duly authorized. OMNICOM GROUP, INC. Date: March 6, 1998 By: /s/Barry J. Wagner ----------------------------- Barry J. Wagner Secretary and General Counsel -3- Index to Exhibits Exhibit Number Description of Exhibit Method of Filing - ------ ---------------------- ---------------- 1.3 Underwriting Agreement by and between Registrant Filed herewith and Morgan Stanley & Co. Incorporated, dated March 4, 1998 (for Common Stock) 4.11 Specimen certificate representing shares of the Filed herewith Registrant's Common Stock. -4-