Billionaire investor Wilbur Ross said on Sunday he is prepared to commit up to 500 million pounds ($760 million) to support Virgin Money in its bid to buy the branch network of the Royal Bank of Scotland .

Ross said he has also invested $100 million ($152 million) in Virgin Money, after finishing negotiations over the weekend. That would give him a 21 percent stake in Virgin Money, a source familiar with the situation said. Ross teamed up with Virgin in 2007 when it attempted to buy lender Northern Rock and said he had been following its progress since.

Virgin Money is the consumer credit arm of entrepreneur Richard Branson's Virgin Group and has frequently been named as a potential suitor for a slice of the billions of pounds in British banking assets set to be sold over the coming months and years.

The UK banking system is clearly going to go through a big overhaul, Ross told Reuters by telephone. There will equally clearly be some new winners and some new losers.

We think that, given the management team and the reputation that Virgin Money has built up, they are ideally positioned to be one of the big winners, he said.

Ross said his support was intended to help if they're fortunate enough to win the RBS branch network bidding. The support could also be for another institution if Virgin Money doesn't win the bidding, although Ross said the RBS branch network is the current focus and the only one on offer right now.

We're working with them on the due diligence and we're working with them on the bid preparation, so it's not just a blank check, he said.

Ross declined to say what the price of the total bid was. Britain's Sunday Times and Sunday Telegraph put the expected bid price at 2 billion pounds sterling ($3 billion).

Ross confirmed that the deadline for bids for the branches is Tuesday. Virgin Money is expected to submit what is known as an expression of interest for the RBS branches, on Tuesday, the source familiar with the situation said.

RBS, bailed out by UK taxpayers at the height of the financial crisis, was ordered by EU antitrust regulators to sell a string of assets, including more than 300 branches and its insurance arm, to compensate for billions received in state aid.

Other potential bidders for the branches include Spanish bank Santander and National Australia Bank , sources familiar with the situation have told Reuters.

Ross added that Northern Rock could potentially be an opportunity if Virgin doesn't win the RBS branch network bidding and if that asset goes on the market.

Northern Rock was the first major British casualty of the credit crunch in September 2007 and was taken into public ownership after attempts to sell it fell through. Ross said earlier this year he was quite possibly interested in teaming up with Virgin Money to bid for Northern Rock.

Ross' intention to back Virgin Money's bid was earlier reported by the Sunday Telegraph and his investment in Virgin Money itself was reported by the Sunday Times.

Virgin Money declined comment.

(Additional reporting by Rosalba O'Brien in London; Editing by Leslie Adler and Lincoln Feast)

United kingdom Richard Branson Royal Bank of Scotland