Virgin Money, the UK financial services firm that last year bought Northern Rock, would be "very interested" in taking a look at a portfolio of 316 branches that Royal Bank of Scotland has put back up for sale, a source said.
The source said Virgin Money is keen to grow further after the Northern Rock deal and would take a look at the business on offer, but whether it would pursue a deal would depend on issues like integration prospects and price.
Santander on Friday pulled out of the £1.65 billion ($2.65 billion) deal to buy the RBS branches, which come with 1.8 million customers, more than two years after it was struck, blaming delays in its completion.
Thousands of workers are facing mounting uncertainty over their jobs after the collapse of a proposed sale of RBS branches to Santander.
The chief executive of the RBS said it was "disappointing" that a proposed sale of 316 branches to Santander had collapsed.
Royal Bank of Scotland's deal to sell branches to Spain's Santander has collapsed, with one source saying it is "a major blow".