ZURICH, March 17 (Reuters) - Swiss banking giant UBS

will look for merger and acquisitions opportunities in

the United States in the next few years, its chairman told the

NZZ newspaper on Sunday.

UBS, which took over former rival Credit Suisse last June,

wants to expand its U.S. wealth-management business through

potential M&A in the next three or four years, Colm Kelleher

said.

"Only in wealth management and not yet," he added.

Since rescuing Credit Suisse, UBS has faced criticism over a

$1.6 trillion-plus balance sheet that is nearly twice the size

of the Swiss economy and has prompted the country to review its

regulation of systemically important banks.

Kelleher, however, pushed back against calls for UBS to be

subject to higher capital requirements.

"If you have too much capital, you penalise the

shareholders, but also the customers because banking services

become more expensive," he told NZZ.

The first merger of two systemically important global

banking groups also resulted in the return of former boss Sergio

Ermotti for a second stint at the helm.

Kelleher said Ermotti is the right person for the "Herculean

task" of integrating Credit Suisse, adding that he would like

Ermotti's successor to be someone from within UBS.