The Federal Deposit Insurance Corporation sued 16 of the world's largest banks on Friday, accusing them of collusively suppressing interest rates.
The lawsuit, filed in the federal district court in New York, was the latest to accuse financial institutions of conspiring to manipulate Libor, or the London Interbank Offered Rate.
(Read more: Libor: CNBC Explains)
The FDIC said the defendants' conduct caused substantial losses to 38 banks that the U.S. regulator had taken into receivership since 2008, including Washington Mutual Bank and IndyMac Bank.
The lawsuit also named as a defendant the British Banks' Association, the U.K. trade organization which during the period at issue administered Libor.
The FDIC declined CNBC's request for comment.