Virgin Money is poised to bid for 316 branches Royal Bank of Scotland branches, after a deal with Santander collapsed.

The Spanish bank has walked away from from the £1.65bn deal despite two years of negotiations following its agreement to purchase the unit in August 2010.

RBS - which was ordered by the European Commission to sell the branches because it receives state-aid - now has 15 months to find a new buyer.

Billionaire Richard Branson's Virgin Money is understood to be plotting a new offer, having made a preliminary approach on Friday.

Others are also reported to be interested. The Sunday Telegraph reports NBNK will also have a look at the unit, despite having told shareholders it will return remaining capital by the end of the year.

NBNK, led by chief executive Gary Hoffman, lost out to the Co-operative Group in an attempt to take control of a 632-branch unit put up for sale by Lloyds Banking Group.

It is understood Hoffman is considering taking a second look at the RBS division, which is home to £21.7bn of customer deposits.

There is an outside chance that JC Flowers, the private equity house led by Christopher Flowers, will cast its eye over the numbers, according to reports.

However one source told the Sunday Telegraph a bid was unlikely. The original sales process saw five bidders, including JC Flowers.