The bank said negotiations between the British Treasury and the Commission, the executive arm of the European Union, were “in their final stages, and will include some divestments not initially contemplated.”

The bank gave no details about what parts of its business it might be forced to sell.

It was already expected to sell branches in England under the revived Williams & Glyn's name.

“It remains RBS's goal that any required divestments do not threaten its recovery plan which is already under way,” the company said.

RBS said it was also close to agreement with the Treasury about terms for insuring 325 billion pounds (US$530 billion) of troubled assets, a step which will increase the government's stake in the bank from the current 70 percent to more than 80 percent.

Media reports say RBS may have to sell its Churchill and Direct Line insurance operations, a large part of its investment bank, and its U.S. banking arm, Citizens Financial Group. The Providence, Rhode Island-based business employs about 24,000 people.

Reports also suggest that Lloyds Banking Group could shed its mortgage arm, Cheltenham & Gloucester, and Intelligent Finance, an Internet bank.