Merchant, who worked for Barclays in New York from 2006 to 2009, is being looked at by U.S. authorities over his activities while working at Barclays' swaps desk in New York. Merchant's lawyer, John Kenney, was not immediately available for comment.

His departure comes in the wake of a Reuters report that another former Barclays trader, Ryan Reich, "has cooperated" with the federal criminal probe into the alleged rigging of international benchmark interest rates. Merchant was one of Reich's supervising traders at Barclays.

Libor, the London interbank offered rate, is used to set rates on trillions of dollars of contracts for everything from home mortgages to credit cards. The investigation has embroiled banks on both sides of the Atlantic and involves yen and euro rates as well as those for the dollar.

Industry records report that Merchant began working for Barclays in 1998 and remained with the British bank until the end of 2009, after which he went to head a swaps trading desk for UBS in Stamford, Connecticut.

Records maintained by UK securities regulators also show that Merchant was registered as working in Britain from 2001 through parts of 2007.

(Reporting by Jennifer Ablan and Matthew Goldstein; Editing by Gary Hill and Leslie Adler)

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