The Libor rate is used to set trillions of dollars of financial contracts, including mortgages and financial transactions around the world.
The regulator said the manipulation caused substantial losses to 38 US banks which were shut down during and after the 2008 financial crisis.
The sued banks include Barclays, HSBC, Citigroup and Royal Bank of Scotland, the BBC reports.
The British Bankers’ Association (BBA) has also been sued by the regulator – the US Federal Deposit Insurance Corporation (FDIC).
“BBA participated in the alleged scheme to protect the revenue stream it generated from selling Libor licenses and to appease the Panel Bank Defendants that were members of the BBA,” it was quoted as saying by the AFP news agency.
The FDIC alleged that the banks mentioned in its lawsuit rigged the rate from August 2007 to at least mid-2011.
Other banks named in the lawsuit include Bank of America, JPMorgan Chase, Deutsche Bank, Lloyds Bank, Credit Suisse, UBS, and Rabobank.