HSBC exec says stolen data was incomplete -paper

* HSBC has so far seen a list with seven names on it

* Data hard to evaluate both technically and legally

ZURICH, Dec 20 (Reuters) - Client data stolen from HSBC's HSBA.L offshore banking headquarters in Geneva was incomplete and inaccurate, the head of HSBC's private banking operations in Switzerland was quoted as saying on Sunday.

The data, taken by former HSBC IT specialist Herve Falciani in 2006 and 2007, has been handed over to French tax authorities and has cast doubt over the ratification of a tax treaty between Switzerland and France.[ID:nN16116709]

“What we have seen so far is a list with seven names. The Federal Public Prosecutor showed us this. The data from Falciani, that I have seen, are incomplete and inaccurate,” Alexandre Zeller, CEO of HSBC Private Bank (Suisse), said in an interview with Swiss newspaper SonntagsZeitung.

“The person, who we employed for eight years, took the data from various systems and tried to put them together like a puzzle. It is difficult to evaluate this data both from a technical and legal point of view.”

HSBC confirmed earlier this month that an ex-employee stole client data from its Swiss private bank in 2006 and 2007. Falciani later identified himself as that ex-employee. [ID:nGEE5B81AP]

The bank has filed a criminal complaint with the Swiss authorities.

Swiss Finance Minister Hans-Rudolf Merz last week asked parliament to suspend the French tax deal until there was more clarity about what happened.

Switzerland has promised to enter new tax treaties that would allow it to share bank client information in some cases of tax evasion in the wake of a global crackdown on tax havens. France and Switzerland signed one such treaty in August, but it has yet to be ratified by the Swiss parliament.

Reporting by Katie Reid; editing by John Stonestreet