Bernhard Schmid, the head of UBS AG’s legal department, left Switzerland’s biggest bank by assets to become a partner at a Zurich law firm founded by a former banker.

Schmid joined Kuoni Attorneys at Law on Feb. 1 to help the company increase its work advising banks, founding partner Wolfram Kuoni said by telephone yesterday. Schmid, who is Swiss, was one of three lawyers to share former General Counsel Peter Kurer’s workload when Kurer became chairman of the bank in 2008.

UBS paid a $780 million fine and disclosed the names of 255 account holders in February 2009 to avoid criminal prosecution in the U.S. on a charge that it helped thousands of wealthy Americans evade taxes. The bank hired Markus Diethelm from Swiss Reinsurance Co. to replace Kurer as general counsel in 2008.

Schmid is “wonderful for a firm like mine to tap into the banking market. He has an outstanding track-record,” Kuoni said in a telephone interview yesterday, adding that he wants to expand the practice’s work advising banks “one tier below” UBS and Credit Suisse Group AG, Switzerland’s biggest bank by market value.