The U.S. Federal Deposit Insurance Corp. is suing 16 big banks, including the Royal Bank of Canada, for alleged rigging of a key global interest rate.
The FDIC accuses them of fraud and conspiring to keep the rate low to enrich themselves.
The banks, which also include Bank of America, Citigroup and JPMorgan Chase in the U.S., are among the world's largest.
The FDIC says it is seeking to recover losses suffered from the rate manipulation by 10 U.S. banks that failed during the financial crisis and were taken over by the agency.
The civil lawsuit was filed Friday in federal court in Manhattan.
The banks rigged the London interbank offered rate, or Libor, from August 2007 to at least mid-2011, the FDIC alleged. The Libor affects trillions of dollars in contracts around the world, including mortgages, bonds and consumer loans.