LONDON (AFP)--- Barclays chairman Marcus Agius resigned on Monday, saying suspected manipulation of inter-bank lending rates by staff had “dealt a devastating blow” to the reputation of the British banking giant.

Barclays said Agius, who has chaired the bank for six years, would remain in his post until a successor was found.

“I am truly sorry that our customers, clients, employees and shareholders have been let down,” Agius said in a company statement, less than a week after the bank was fined over the rate rigging scandal.

Barclays on Monday added that it would launch an independent audit that would “undertake a root and branch review of all of the past practices that have been revealed as flawed since the credit crisis started.”

Barclays insisted that it would establish “a zero tolerance policy for any actions that harm the reputation of the bank.”

Britain‘s Business Secretary Vince Cable on Sunday backed calls for a criminal investigation into bankers involved in the scandal, which cost Barclays 290 million pounds ($450 million) in fines.