Omnicom is understood to have hired investment banker Randy Weisenburger as its chief financial officer to replace Fred Meyer, who is retiring.
Weisenburger, 39, will work closely with John Wren, president and chief executive officer of Omnicom, which owns agency networks BBDO, DDB and TBWA.
It is thought the two men will form the core of an aggressive management team at Omnicom ready to make more acquisitions.
They are younger than the old leadership – Bruce Crawford, 69, made way for 45-year-old Wren last year and Meyer, who is 67.
Weisenburger is a managing director of US blue chip investment company Wasserstein Perella, which provides asset management services around the world. It owned the troubled UK cosmetics company Yardley before it was put into receivership during the summer. He has held directorships in Maybelline Inc and Alliance Entertainment Corporation.
Omnicom has made a number of acquisitions recently – buying the GGT/BDDP network and earlier adding Simons Palmer Clemmow Johnson in the UK to its TBWA network. There has been much speculation on Wall Street about its proposed acquisition programme, and its share price soared on rumours in July. Wren says the company could grow by up to a fifth by the end of next year.