"Rupert has been the de facto COO of Group M for quite some time now while also carrying the heavy responsibilities of chief financial officer, but it's simply too much of a load for one person," Mr. Gotlieb said in a statement. "This move recognizes the great work he's been doing for us as well as the need for a deeper management structure at Group M."
Mr. Day's duties will be strategic, administrative and operational, all involving Group M operating agencies. He'll also work with WPP to explore and develop new business opportunities, acquisitions and joint ventures worldwide.
The position, based in New York, is a new one at Group M, which houses MindShare, Mediaedge:cia, MediaCom and Maxus. Mr. Day has been chief financial officer for Group M since 2003 and prior to that worked in numerous WPP subsidiary companies. He was, for instance, one of a core group of executives who launched MindShare globally.