According to the SonntagsZeitung, which cited an unnamed source familiar with the matter, the account details belonged to American individuals with offshore accounts at both Credit Suisse and Clariden Leu, a subsidiary of the institution.
Credit Suisse is thought to be complying with a request for the information by the Swiss government although the bank has not said how many names are to be included in the hand over.
Last week, the Swiss bank revealed it set aside â¬295 million in its third quarter financial figures as provision for a potential settlement although reports suggest that the final figure may be more.
Teresa Nielsen, Vontobel analyst, told Reuters: "In our view the US tax matter and data handover is advancing faster than expected which we believe is positive for Credit Suisse as we could potentially see a conclusion to this matter earlier than we previously expected.â
In 2009 UBS avoided criminal charges in a similar case by paying a fine of $780 million after the Swiss authorities reached an agreement with the US.
By Jim Ottewill