EXHIBIT 23.4




March 7, 1996


We  hereby  consent  to the  incorporation  by  reference  in this  Registration
Statement  of  Omnicom  Group  Inc.  of our tax  opinion to the Board of Ketchum
Communications  Holdings, Inc. dated March 7, 1996, to the filing of our opinion
as an  exhibit  to the  Registration  Statement,  to the  summarization  of this
opinion in the "Federal  Income Tax  Consequences"  section of the  Registration
Statement  and to all  references  to our  Firm  included  in this  Registration
Statement.




Deloitte & Touche LLP
DELOITTE & TOUCHE LLP