Royal Bank of Scotland Group PLC (LON:RBS) and Bank of America Corp (NYSE:BAC) are reportedly being sued by investors in the US over the two lenders' alleged roles in a $9.4trn European government bond market rigging conspiracy.
Reuters said the proposed class-action complaint accusing the banks of violating federal anti-trust law was filed on Monday night in the US District Court in New Haven, Connecticut.
The move follows an announcement by the European Union's anti-trust authority, published on 31 January, which accused eight banks of being part of a cartel to distort bond prices from 2007 to 2012.
The European Commission said it believed bond traders may have illegally shared commercially sensitive information and co-ordinated trading strategies, mainly through online chatrooms.
While the commission did not identify the eight banks said to be involved, media reports at the time suggested RBS and Bank of America were among them.
Reuters said spokespersons for RBS and Bank of America both declined to comment on the lawsuit report.