A UBS spokeswoman confirmed a Financial Times report, which said UBS and four other banks were preparing to take back millions of dollars in bonuses from traders.

Regulators on Wednesday fined six major banks a total of $4.3 billion (2.74 billion pounds) for failing to stop traders from trying to manipulate the foreign exchange market, following a year-long global investigation.

Switzerland's financial regulator said on the same day that it had begun enforcement proceedings against 11 former and current unnamed UBS employees and that it would limit bonuses for some employees of the bank.

HSBC Holdings Plc, Royal Bank of Scotland Group Plc, JPMorgan Chase & Co and Citigroup Inc are the other banks looking to take back bonuses, according to the FT report.

JPMorgan declined to comment on the FT report, while RBS, Citigroup and HSBC were not immediately available to comment.

(Additional reporting by Anil D'Silva in Bangalore)

By Neha Dimri