* Swiss asked for help in investigation - source
* Comes as regulators crack down on tax evasion
* Amount at stake 850 mln eur, UBS “cooperating”-Le Monde
PARIS, April 18 (Reuters) - France has contacted Swiss authorities for help in determining whether 353 prospective UBS clients in France have undeclared assets in Switzerland, a source close to the matter said on Thursday.
Around 50 names on the list, which emerged as part of an ongoing French probe into UBS’s business practices and whether the bank offered illicit products that would avoid tax, have already been confirmed as owning a Swiss bank account, French newspaper Le Monde reported earlier.
Regulators across the world are cracking down on tax evasion and money laundering in the wake of the financial crisis. The Swiss and U.S. governments are locked in talks over accusations that Swiss banks helped wealthy Americans evade billions of dollars in taxes.
The French government is also fighting an extra battle on home turf to regain public trust after Budget Minister Jerome Cahuzac quit and admitted to having held an undeclared Swiss bank account.
Le Monde said the French Budget Ministry confirmed the existence of the probe and said 850 million euros ($1.1 billion) were at stake. When contacted by Reuters, the Budget Ministry declined to comment.
UBS France’s head, Jean-Frederic de Leusse, told the newspaper the bank was cooperating fully with the authorities.
A spokesman for the relevant Swiss authority, the Federal Tax Administration office, declined to comment, citing confidentiality rules covering the double taxation treaty with France.
UBS is still being probed by the French judiciary over whether it offered potential French clients investments that were allegedly designed to cheat the taxman.
Three UBS France executives are being investigated as part of the probe, a judicial source told Reuters.
$1 = 0.7668 euros Reporting by Gerard Bon and Lionel Laurent; Additional reporting by Martin Martin de Sa'Pinto in Zurich; Editing by Catherine Bremer and Mark Potter