Citigroup said it could plead guilty to an antitrust charge to resolve a U.S. Department of Justice investigation of its dealings in foreign exchange markets.
In a regulatory filing on Monday, the company also said the Justice Department had advised that it did not intend to prosecute the bank in a separate investigation into the setting of interest rates between banks.
Citigroup is one of six major banks that have been under investigation over the past year by global authorities, including the DOJ, for trying to manipulate rates in the $5-trillion-a-day foreign exchange market.
The banks have been accused of sharing confidential information about client orders and coordinating trades from 2008 until October 2013 to boost their own profits.
Bloomberg, citing sources, reported last month that the DOJ had been pressing Citigroup's main unit to plead guilty to criminal charges. It said Citigroup had countered with an offer that the plea come from a subsidiary that is smaller than the Citibank NA unit.
Bloomberg said the related fine would likely not exceed $1 billion.
Citigroup left its estimate of potential unreserved litigation costs unchanged from year-end at $4 billion.