RBS is set to announce the sale of 318 branches to Spain's Santander as the UK lender offloads the former Williams & Glyn's network.
Santander UK has reported its profits rose 10% in the first six months of 2010 to £875m.
Spanish banking giant Santander is planning to list its UK operations on the London Stock Exchange as soon as this autumn in a deal worth an estimated £3bn.
Santander, Spain's biggest bank, is the sole remaining bidder for the 318 Williams & Glynn branches being offloaded by Royal Bank of Scotland.
Santander has reportedly entered its final offer for Royal Bank of Scotland's (RBS') network of 318 UK branches.
Spanish banking giant BBVA is considering a £2bn takeover bid for the British arm of National Australia Bank (NAB), which includes Clydesdale and Yorkshire banks.
Britain and France are at odds with other European Union countries over plans to insure against future bank failures, in another sign of the problems in trying to forge a common response to the bloc's economic woes.
Spanish banking giant Santander was suspicious of Bernard Madoff's activities as far back as 2006, internal documents show.
Virgin Money has been dropped from the race to buy up 318 RBS branches, sources familiar with the matter said at the weekend.
Santander UK profits grew more than 15% in the first three months of the year to £426m, with revenue up 8%.