Barclays will contest a record $453 million fine imposed by a US energy regulator against the British bank and four of its power traders, setting up a likely federal court battle.

The fine, which was upheld by the Federal Energy Regulatory Commission (FERC) on Tuesday, confirm the top US energy watchdog will pursue its most ambitious market manipulation case to date.

For Barclays, the sanction is the latest of a series of scandals that include a $450 million fine by US and UK regulators for rigging global benchmark interest rates last year. But unlike its settlement over Libor (London Interbank Offered Rate), where the bank accepted wrongdoing, it has fought the FERC allegations from the start.

FERC first proposed the fines in October 2012 over alleged manipulation of Californian and other western power markets by the British bank in the last decade.

Reuters