ICAP, the UK interdealer broker, has agreed to pay to US and UK regulators ￡55m to settle allegations that some of its employees – including one known to his peers as “Lord Libor” – were the conduit by which yen Libor rates were manipulated around the world.

The US Department of Justice also filed criminal charges against three former ICAP employees. The complaint alleges that they helped a then-UBS trader’s attempts to manipulate yen Libor rates by spreading misinformation about the interbank lending market to other banks. They were seeking to ensure that daily yen Libor rates were set at levels that benefited the trader’s positions, the complaint said.

Wednesday’s settlement underscores the influence ICAP wielded on the rate-setting process and the critical role it played. The interdealer broker, founded in the 1980s by former Conservative party Treasurer Michael Spencer, accepted as part of Wednesday’s settlement that employees had colluded with traders in banks to attempt to manipulate the London Interbank Offered Rate between 2006 and 2010.