AS Royal Bank of Scotland continues to transform itself into a UK-facing operation under chief executive Ross McEwan, a new report has claimed that the strategy could end up losing the Edinburgh-based bank some important customers.

Bloomberg Business yesterday reported that RBS risks the loss of some of the British clients it wants to prioritise, according to a study of the group’s customers across the UK.

The report was causing some consternation at RBS last night – particularly as the study was not openly published, either to the trade press generally or on the website of the company which is named as responsible for the research, East & Partners.

“Have you seen it?” RBS asked The National, but our information had come from the respected business information organisation.

According to Bloomberg’s report of the East & Partners study, executives at more than a quarter of the surveyed companies said RBS’s plan to withdraw from corporate and institutional banking in 25 countries would affect their choice of banking partner.

It was reported that about 36 per cent of the 107 people questioned said it could possibly influence them.

Brought in to turn state-owned RBS into a bank fit for returning to the private sector – Chancellor George Osborne has said that the process will be completed in the lifetime of the current Parliament – McEwan has repeatedly emphasised the need for RBS to concentrate on UK consumer and commercial lending.

The policy of exiting the bank’s non-core operations around the world has helped overturn seven years of annual losses, and at the beginning of August, Osborne authorised the sale of the first tranche of RBS shares.

The sale of 5.4 per cent of the shares, at 330p a share, raised £2.1 billion – a loss of more than £1bn on the price of about 500p paid for the shares by the Labour government in 2008 and 2009.

Any research indicating that RBS’s current policy may lose it customers rather than gain them could affect the sale of the next tranche of share. The Government still owns 73 per cent of the bank, which posted a profit of £293 million in the second quarter of the year.

UK Financial Investments, the vehicle through which the UK Government owns its shares, indicated to the City at the time of the first share sale that there would be no further sales for 90 days, a period which ends in less than four weeks’ time.

It was reported earlier this week that RBS would be undertaking a rebranding exercise, and despite the share sell-off, the bank was also bidding to buy the £13bn worth of mortgages put up for sale by the UK Government – loans it acquired when Northern Rock was nationalised.

However, the new study appears to question such UK-facing activity. According to Bloomberg’s report, “leading companies such as Royal Dutch Shell Plc, the world’s second-biggest oil company by sales, have sought to find other providers for some services as a result of the overhaul,” with the source being described as “people with knowledge of the matter”.

Bloomberg quoted Paul Dowling, principal analyst at East & Partners Europe, as saying: “The bank’s withdrawal from a number of global markets comes with some pretty clear negative outcomes. There are significant revenue and relationships risks implied here for RBS’s domestic UK franchise.”

RBS is not the only British bank pulling out of foreign corporate markets. According to Bloomberg: “More than a third of 773 UK companies surveyed said the gradual retreat of British banks from global operations may make them reconsider their choice of corporate banking partner.”

A spokesman for RBS said: “We have not yet seen this report and therefore cannot comment on it.”