The rate-rigging scandal has claimed its first scalp as Barclays
confirmed its chairman Marcus Agius is to step down.
Mr Agius, who was chairman for six years, said: "This has been a period of unprecedented stress and turmoil for the banking industry in particular and for the wider world economy in general."
The move comes after Barclays was fined £290 million by UK and US regulators for manipulating the Libor, the rate at which banks lend to each other.
The bank said Mr Agius will remain in post until an "orderly succession is assured" and added Barclays non-executive director Sir Michael Rake has been appointed deputy chairman.
Mr Agius added: "I am truly sorry that our customers, clients, employees and shareholders have been let down. Barclays is full of hard-working, talented individuals whose integrity is not in question."
The bank has also agreed to launch an audit, led by Sir Michael, to review "flawed" past practices that have been revealed.
The findings of the inquiry will be revealed in a public report and the bank will produce a new, mandatory code of conduct.
Mr Agius said: "Last week's events - evidencing as they do unacceptable standards of behaviour within the bank - have dealt a devastating blow to Barclays' reputation.
"As chairman, I am the ultimate guardian of the bank's reputation. Accordingly, the buck stops with me and I must acknowledge responsibility by standing aside."
He added: "It goes without saying that Barclays will continue to have my wholehearted support in the future."