Credit Suisse will pass the names of clients holding French securities to the French markets authority, media reports said.

Partly confirming an article in Swiss daily Le Temps, a Credit Suisse spokesman was quoted as saying that the Swiss bank has sent a letter to French clients holding French stocks or bonds.

The letter sought authorisation to pass on information to the Autorite des Marches Financiers the financial markets regulator, the spokesman said.

The disclosure move comes at a time when Credit Suisse’s Swiss rival, UBS, is coming under heavy pressure in the US to hand over details of up to 52,000 client details to the authorities. So far, UBS has refused to do so. The issue has raised questions about whether Swiss banks can continue to defend their centuries-old practice of bank secrecy.

Reuters quoted a Credit Suisse spokesman as saying that the AMF could also request information on non-French nationals holding French securities, and said non-French clients holding French securities would also be contacted.

"We have to be in a position to disclose this information if required to do so by the AMF," he said.

Credit Suisse said the request for clients to authorise disclosures on details such as the beneficial owner of French securities and their trading records was not related to a tax treaty signed by Switzerland and France in June.