NEW YORK (Reuters) — UBS AG, the world’s biggest money manager for wealthy people, said yesterday that Mark Sutton, chairman and chief executive of UBS Americas, will step down at year-end after just 18 months on the job.Robert Wolf, the chief operating officer of UBS’ investment banking unit, will succeed Sutton effective January 1 and retain the COO position.

Huw Jenkins, who heads the investment bank, will assume responsibility for the Americas region on UBS’ executive board. The region includes the Swiss bank’s US, Canadian and Latin American operations.

Sutton, 52, said in an interview he had mulled a departure for several months. He said he is leaving to pursue other business opportunities and spend more time with his family.