As RBS prepares to announce its annual figures, there is speculation that the bank has hit further troubles in trying to offload the 316 branches to meet EU rules on state aid.
Following the collapse of the bank's sale to Santander, RBS is said to be looking at selling a minority stake to private equity and institutional investors to kick-start the auction process.
The bank has already cut its investment banking finance from £500 billion in 2008 to £300 billion.
RBS has also cut more than 5,000 jobs, with its investment arm now employing around 11,000 people.
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