UBS AG, Switzerland's biggest bank, agreed to sell its stake in private-equity fund manager Adam Street Partners LLC to the company's other shareholders for US$156 million.

The Zurich-based bank agreed to sell the 24.9-percent stake on May 5, according to the prospectus for its 16 billion-franc (US$15.6 billion) rights offer, published on the company's Website late Friday. The sale is expected to be completed in the second quarter, UBS said.

Adam Street Partners was formed in January 2001 when management bought out the business from UBS's asset management division. UBS said it will continue its "close collaboration" with Chicago-based Adam Street after the stake sale.