UBS Tuesday named Robert J. McCann as Chief Executive of its wealth management units in the Americas, as it attempts to bolster its U.S. operations in the wake of a tax disagreement with authorities there.

UBS said that McCann, 51, who joins from Merrill Lynch, where he worked for 26 years until January 2009, will immediately assume responsibility for UBS's domestic Americas wealth management businesses, including all international business booked in the U.S.