U.S., Swiss Ask for Delay in UBS Tax Case

UBS also paid a $780 million penalty.

"Until its activities were discovered, UBS -- on U.S. soil -- regularly violated U.S. law, and actively helped its customers violate U.S. law," said Justice Department tax attorney Stuart Gibson, the lead U.S. lawyer on the case.

The 300 names were released under an exception to Swiss banking secrecy law when clients deliberately defrauded tax authorities, as opposed to failing to declare all assets.

Abusive tax shelters and hidden offshore accounts cost the U.S. government an estimated $100 billion a year in lost tax revenue, according to Sen. Carl Levin (D., Mich.) chairman of the Senate Permanent Subcommittee on Investigations.

The Justice Department has brought several other UBS-related tax cases in South Florida, including a November 2008 indictment charging former bank executive Raoul Weil with conspiring to defraud the government. Weil, who ran UBS cross-border and private banking operations, is a fugitive living in Switzerland, and his lawyer has insisted he is innocent.

In June 2008 former UBS banker Bradley Birkenfeld pleaded guilty to a similar charge -- he helped a California billionaire evade taxes -- and has been cooperating extensively with federal prosecutors and the IRS. He has not yet been sentenced.