Credit Suisse says the US Internal Revenue Service recently submitted its request to Swiss authorities citing a 1996 treaty between the two countries.

The bank confirmed reports that it has notified an unspecified number of American clients that their data will be automatically handed over to Swiss authorities for examination.

Credit Suisse says clients will have the opportunity to lodge an appeal before Swiss authorities forward any information to the IRS.

The Zurich-based bank said last month it had set aside 295 million Swiss francs ($329 million) in connection with a US probe into whether it aided American tax cheats.