MILAN: UBS loss in Switzerland's high court on Friday will put its rivals in the crosshairs. The country's top judges are letting French authorities have details on some 40,000 of the bank's clients. How much this will help Paris secure a 4.5 billion euro fine in its current UBS tax-fraud case is unclear. But it opens the door for overseas agencies to target the entire Swiss banking industry.

Friday's court decision is consistent with the Alpine state's drive to leave behind its tax-haven past and help fight money laundering and fraud. Under pressure from the United States and the European Union, Switzerland has over a decade progressively dismantled its banking-secrecy laws and last year started to automatically share bank depositors' information with OECD partners. But older client data, like the ones linked to Friday's court decision, have been more difficult to extract.

The ruling complicates matters for UBS while it's fighting a multi-billion-euro French tax penalty. The world's biggest wealth manager is currently appealing a court case that found it guilty of illegally soliciting French clients and helping them hide cash in Swiss bank accounts. Fresh information about thousands of UBS depositors could weaken the Swiss bank's hand.

There is a caveat - the Swiss supreme court says the new data should not be used as evidence for the French prosecution against the bank run by Sergio Ermotti. But Switzerland may not be able to ensure that happens once that information crosses the border. France and Germany have supported legal shortcuts to charge people with tax evasion, including using databases stolen from Swiss wealth managers. A list swiped in 2008 by IT specialist Herve Falciani exposed, for instance, wrongdoing at the Swiss arm of HSBC.

Bank-secrecy erosion has already resulted in large fines for many Swiss private banks. Friday's green light to such mass-sharing of data may entice France or other foreign authorities to place more requests for information. UBS's peers may well need to brace for more pain.