In the final stages of a long-running investigation into corruption in the world's largest financial market, federal prosecutors have recently informed Barclays, JPMorgan Chase, the Royal Bank of Scotland and Citigroup that they must enter guilty pleas to settle the cases, the newspaper reported.

The pleas would be likely to carry a symbolic stigma, if limited actual fallout, in handing felony convictions to some of the world's biggest banks, the newspaper said. (http://nyti.ms/1DVNiVe)

A spokesman for RBS declined to comment on the report. Representatives of Citigroup, JP Morgan, and Barclays did not respond to emails seeking comment on the report. Reuters could not immediately reach the DoJ for comment outside regular U.S. business hours.

Last November, regulators fined six major banks a total of $4.3 billion for failing to stop traders from trying to manipulate the foreign exchange market, following a yearlong global investigation.

Authorities accused dealers of sharing confidential information about client orders and coordinating trades to boost their own profits. The foreign exchange benchmark they allegedly manipulated is used by asset managers and corporate treasurers to value their holdings.

(Reporting by Supriya Kurane in Bengaluru; Editing by Gopakumar Warrier)