The U.S. Department of Justice also issued a request to HSBC Holdings in November seeking documents related to a criminal antitrust investigation that the DoJ is conducting in relation to precious metals, it added.

"HSBC is cooperating with the U.S. authorities in their respective investigations," the bank said. "These matters are at an early stage."

HSBC was one of a number of banks named in lawsuits filed in U.S. courts last year alleging a conspiracy to manipulate gold, silver, platinum and palladium prices, plus precious metals derivatives, during the daily precious metals fixes.

HSBC said in Monday's statement that it filed a response this month to an amended consolidated class-action complaint concerning gold that was filed in December 2014, and that it will respond next month to allegations of silver price fixing.

It did not disclose any details about the response.

The banks involved in production of precious metals benchmarks, known as the 'fixes', said last year that they would no longer administer that process.

An electronic daily silver price benchmark is now administered by Thomson Reuters and CME Group, while the London Metal Exchange provides twice-daily benchmark platinum and palladium prices.

ICE Benchmark Administration (IBA) will run an electronic gold price benchmark from March 20 to replace the century-old London gold fix.

By Jan Harvey