Three indicted former traders, all U.K. nationals who worked for major international banks, surrendered Monday to U.S. officials, the U.S. Department of Justice announced. They were indicted in January for conspiring to fix prices and rig bids for U.S. dollars and euros in a foreign currency exchange.

Richard Usher, Rohan Ramchandani and Christopher Ashton were indicted Jan. 10 on one count each of conspiring to restrain trade in the foreign currency spot market by the U.S. Attorney's Office for the Southern District of New York.

Usher, a former trader with affiliates of The Royal Bank of Scotland; Ramchandani, a former trader at an affiliate of Citicorp; and Ashton, a former trader at an affiliate of Barclays, who were known as “the Cartel” or “the Mafia,” prosecutors say, coordinated trading activity, agreeing to suppress and eliminate competition in the FX Spot Market.