BC-GERMANY-SWITZERLAND/BANK (UPDATE 1)

UPDATE 1-Germany prepared to pay for secret Swiss bank data

+ Informant offers Germany data of potential tax evaders

+ Merkel says Germany will do everything to obtain data

+ Fear UBS data may be involved hits stock-traders (Updates with Merkel, adds detail, background)

By Sarah Marsh

BERLIN, Feb 1 (Reuters) - Germany should do everything in its power to obtain data to fight tax evasion, Chancellor Angela Merkel said on Monday after a whistleblower offered to sell German authorities secret Swiss bank data.

The informant has offered data of up to 1,500 possible tax evaders with accounts in Switzerland which could lead to 100 million euros for state coffers, media reported.

"Everything should be done to get this data," Merkel said at a news conference in Berlin. "We should aim to acquire this data if it is relevant (to fighting tax evasion)."

The case could ignite a fresh tax row between Germany and Switzerland. Top Swiss politicians, including President Doris Leuthard, and bankers warned Germany against acquiring the data.

It has also caused a stir in Germany, where memories of the Nazi Gestapo and Communist East Germany's Stasi security police have made the public wary of any invasion of privacy.

A spokesman for the German Finance Ministry said the country was in principle willing to purchase bank data on suspected tax evaders even if the information was obtained illegally.

"The decision will be based on the line that was established with the Liechtenstein case in 2008," said Finance Ministry spokesman Michael Offer.

In this case, Germany purchased stolen data from an informant about clients of Liechtenstein's main bank LGT, prompting a huge investigation into tax evasion.

The case snared former Deutsche Post chief Klaus Zumwinkel, who was given a suspended jail term for evading nearly a million euros in taxes using a Liechtenstein trust.

Offer said it was the responsibility of individual German states to decide what to do with such data, in cooperation with the federal government. He said the authorities were seeking to quickly clarify legal issues surrounding the case.

Shares in Swiss bank UBS fell on Monday to a 6-1/2 month low, chiefly due to comments by the country's justice minister about the risk to the Swiss economy should the bank's settlement of a U.S. tax dispute unravel.

However, traders said the weekend reports that Germany was considering buying data on bank accounts in Switzerland was also hitting the stock as investors feared that some could belong to UBS, Switzerland's biggest wealth manager. (Additional reporting by Dave Graham and Erik Kirschbaum in Berlin and Lisa Jucca in Zurich; editing by Ralph Boulton)

REUTERS