An Interpublic spokesman declined to comment.
Mr. Carlin is currently chairman of Interpublic's Universal McCann. In his new capacity, Mr. Carlin will be put in charge of selling the shop's media negotiating services to Interpublic offices and clients worldwide, executives said.
Mr. Carlin had not returned a phone request for comment by press time.
Bill Cella remains as chairman of Magna Global in the U.S.
The management shift will place Robin Kent in a leadership position at Universal McCann Worldwide, perhaps to be named CEO of Universal McCann Worldwide.
Mr. Kent currently holds the dual title of president of the worldwide entity and of its North American operations.
Mr. Kent had not returned a phone request for comment by press time.
According to executives, the shop is also interviewing prospective candidates to take over North American duties.