NEW YORK (AP) — The Department of Justice has opened a criminal investigation into JPMorgan Chase’s foreign exchange business.

The announcement by the nation’s largest bank follows a similar disclosure Thursday by Citigroup. Banks in the U.S. and abroad are facing allegations that they manipulated foreign-exchange rates. Besides the Justice Department, JPMorgan says civil enforcement authorities and foreign regulators are also investigating its foreign exchange business.

The New York bank said late Monday in a filing with the U.S. Securities and Exchange Commission that it had boosted the amount of money set aside for legal expenses. It now has $5.9 billion in reserve, up from the $4.6 billion it reported in August.

JPMorgan Chase & Co. has paid billions in penalties since the financial crises related to mortgages and huge investor losses.

Shares edged lower before the opening bell Tuesday.

Copyright 2014 The Associated Press. All rights reserved. This material may not be published, broadcast, rewritten or redistributed.