The chief executive of Clydesdale Bank parent National Australia Bank has revealed he is looking “very closely” at the 300-plus branches in England and Wales which have been put up for sale by Royal Bank of Scotland.

Referring to the sell-off of RBS branches which was ordered earlier this month by the European Commission under the state-aid regime, NAB chief executive Cameron Clyne told a business lunch in Australia: “We’ve been watching it very closely and we’re very keen to see how it develops.’’

RBS, which announced this month that the UK government would be injecting further capital of £25.5bn on top of £20bn provided previously by the taxpayer, is selling a total of 318 branches under the state-aid-related deal hammered out with Europe.

All but a handful of these branches are south of the Border, with a concentration in the north-west of England.

The bulk of the branches being sold off by Royal grew out of its former Williams & Glyn’s business.

Royal has said the 318 branches which it has put up for sale have 1.7 million retail banking and 230,000 small and medium-sized business customers, and employ 6000 staff, with a combined loan book of £20bn.

It has said these branches have a total 5% share of both the small and medium-sized enterprise and mid-corporate banking markets in the UK, and a 2% share of retail banking.

However, while interested in taking a look, Clyne appeared unsure about how a disposal would be structured in spite of these numerical details supplied by Royal.

He signalled a belief that it remained unclear whether the operations would be sold as discrete businesses orindividual branches, and highlighted potential complexity.

Clyne told the Australia-Israel Chamber of Commerce event in Sydney: “If you’re trying to carve off branches, it can be a very complex transaction.”

Glasgow-based Clydesdale Bank’s operations are concentrated in its Scottish heartland, although it has been building a presence in the south of England.

NAB’s other big UK operation is Yorkshire Bank, which has the bulk of its branches in Yorkshire and the north-east of England, and also has some operations in the Midlands.

With the RBS branches which are on the auction block concentrated in the north-west of England, they would allow NAB to expand in a territory in which it has not had a particularly significant presence.

A spokesman for Clydesdale Bank told The Herald last night: “Cameron (Clyne) has always said the UK operations are strong.

“We have had a strong organic growth strategy.

“While that remains our priority, if there are bolt-on acquisition opportunities it would be appropriate to at least look at them.”