ZURICH (Reuters) - Swiss tax authorities are to hire more staff to deal with a flood of requests for information from countries trying to track down tax cheats using Swiss bank accounts - increasing the size of the team from six to 14.

The government said on Wednesday it had granted permission for the finance department to add eight new staff to a group created in 2011, after Switzerland promised to relax its traditional bank secrecy and do more to help stop tax evasion.

It said the increase was necessary so that Switzerland could meet its international obligations in an efficient way, noting it had received 704 requests for assistance in tax affairs from foreign authorities so far this year, compared to 370 last year.

Since bowing to global pressure to weaken bank secrecy in 2009, Switzerland has agreed new double taxation treaties with 25 countries, which can all now make more wide-ranging requests for information on the accounts of suspected tax dodgers.

Switzerland's $2 trillion offshore wealth management industry looks set to lose hundreds of billions of francs (dollars) as a result of steps to stop foreigners using secret accounts to evade tax.

Switzerland has struck deals with Germany, Britain and Austria to allow citizens to pay tax on secret accounts without revealing their identities, although the German agreement looks likely to be blocked by the opposition Social Democrats.

It is also trying to end investigations by U.S. tax authorities into 11 banks, including Credit Suisse and Julius Baer, in return for the payment of hefty fines and the transfer of names of thousands of U.S. bank clients.

(Reporting by Emma Thomasson; editing by Andrew Roche)