The break-up of Switzerland's oldest bank Wegelin on Friday shows the need to settle a dispute with U.S. authorities over tax cheats hiding cash in secret Swiss accounts, the finance minister said on Saturday.

Eveline Widmer-Schlumpf

"It is very regrettable," Eveline Widmer-Schlumpf told journalists at the World Economic Forum of the decision by Wegelin to break itself up in the face of possible indictment on charges the bank helped wealthy Americans to evade taxes.

"This development shows how important it is that we come to solutions in the discussions, negotiations with the United States which hopefully prevent other banks getting into a similar situation," she said.

The U.S. Department of Justice is probing 11 Swiss banks, including Credit Suisse, Julius Baer and Basler Kantonalbank.

"I don't know whether other banks are in a similar or same situation...but what I know is that various banks are being threatened by the United States with prosecution and we will try to do everything...to come to a solution," Widmer-Schlumpf said.

Switzerland has been lobbying for a year to get the investigations dropped in return for the payment of a hefty fine and the transfer of names of thousands of U.S. bank clients suspected of dodging taxes.

UBS paid $780 million to settle U.S. criminal charges in 2009 and also turned over the names of 4,500 clients.

Widmer-Schlumpf, who held talks in Davos this week with U.S. Treasury Secretary Timothy Geithner, said she hoped to reach a deal in the coming months, but declined to comment on the size of the fines under discussion for Swiss banks.

"It is up to the financial institutions to say how much they are prepared to pay. It is not up to the state," she said.

Switzerland struck deals last year with Britain and Germany that would allow their citizens to pay tax on secret accounts without revealing their identities, although these are being challenged by the European Commission which wants to force Switzerland to accept an automatic exchange of bank information.

Widmer-Schlumpf, who also holds the rotating Swiss presidency, said the European Unon had signaled to Switzerland it wanted to discuss a general accord with the bloc.

(Reporting by Emma Thomasson; Editing by Ben Hirschler and Peter Graff)