Criminal Libor Probe: DOJ Investigating World's Biggest Banks On Global Benchmark Rate

NEW YORK, Feb 28 (Reuters) - The U.S. Justice Department is conducting a criminal probe into whether the world's biggest banks manipulated a global benchmark rate that is at the heart of a wide range of loans and derivatives, from trillions of dollars of mortgages and bonds to interest rate swaps , a person familiar with the matter said.

While the Justice Department's inquiry into the setting of the London interbank offered rate, or Libor, was known, the criminal aspect of the probe was not.

A criminal inquiry underscores the serious nature of a worldwide investigation that includes regulators and law-enforcement agencies in the United States, Japan, Canada and the UK.

Several major global banks, including Citigroup Inc , HSBC Holdings Plc, Royal Bank of Scotland Group Plc and UBS AG, have disclosed that they have been approached by authorities investigating how Libor is set.

No bank or trader has been criminally charged in the Libor probes. It wasn't clear which banks or traders the Justice Department is targeting in its criminal probe.