Gosper will also oversee the McCann UK Group as its chairman and chief executive. He will work alongside Giuseppe Usuelli, who was appointed to replace Rupert Howell as the chief executive of McCann EMEA last week.
Michael McLaren, the worldwide director of accounts at the McCann Worldgroup, will be Gosper's replacement in the US.
The chief executive of McCann Worldgroup, John Dooner, said: "This move gives Brett management responsibility for our largest operating region, spanning more than 100 cities in more than 85 countries. By leveraging the strength of our most dynamic leaders, we can energise our ability to drive our clients' products."
Gosper, who is in his second stint at the agency, has led McCann's US operation since September 2005. He was hired from TBWA\New York, where he was the president. With Mark Wnek, Gosper was the architect of a recovery in the 90s at the then Euro RSCG Wnek Gosper in London.
- Newsmaker, page 12.