CO-OPERATIVE Bank offices in Blackburn, Darwen, Colne and Burnley are at risk under plans to cut the branch network by at least 15 per cent next year.

Following a rescue plan where its creditors, led by half-a-dozen hedge funds, acquire 70 per cent of its shares the bank will close 50 of its 324 branches.

But Co-op Group chief executive Euan Sutherland admitted there will be ‘significant’ job losses, saying staff will be informed first.

The company also aims to slash costs across its call centres, while investing in digital and self-service banking.

The group, which traces its roots back to 1844 when a number of workers known as the Rochdale Pioneers pooled resources, took out adverts in national newspapers today to reassure customers it will retain its ethical approach.

It insisted the bank will only be able to use the Co-op name while the ethical principles remain embedded in its constitution.

Mr Sutherland said: “We need to take overall costs down, unfortunately that will hit jobs. We have taken a major step towards achieving our plan to secure the future of the bank.”

The turnaround is expected to take four to five years.

The Co-op added that the bank's outlook remains ‘challenging’, although monthly bad debt charges have fallen.

A bank spokesman said: “While we have announced today that we expect to rationalise our branch network by at least 15 per cent by the end of 2014, at this stage we have not announced individual branches that are due to close.”