European Union antitrust regulators are investigating precious-metals trading following a U.S. probe that embroiled some of the world’s biggest banks.

U.S. prosecutors have been examining whether at least 10 banks, including Barclays Plc, JPMorgan Chase & Co. and Deutsche Bank AG, manipulated prices of precious metals such as silver and gold. The scrutiny follows international probes into the rigging of financial benchmarks for rates and currencies, which have yielded billions of dollars in fines.

In the U.S., UBS Group AG said in May that it won immunity from criminal fraud charges in a Justice Department investigation into misconduct in the trading of precious metals.