LONDON May 2 Royal Bank of Scotland said regulatory investigations and litigation related to its past conduct continued to create challenges and uncertainties for the bank.
It said the timing and amounts of any further settlements or redress remained uncertain.
RBS is among several major banks assisting regulators around the world who are investigation allegations of collusion and price-rigging in the global currency market. Britain's financial regulator is also examining the activities of its restructuring unit.
RBS trebled its profit in the first quarter, benefiting from improved cost control and a reduction in impairment costs.
(Reporting by Matt Scuffham; Editing by Steve Slater)