Sir Nicholas Montagu, chairman of the Financial Ombudsman Service, thanked Ceeney for her service and praised her leadership.
He said: “In the close to four years since joining, Natalie has taken the service from dealing with an annual workload of 150,000 cases to over 500,000 cases – with the organisation trebling in size under her leadership in response to the challenges of PPI.
“So having just received our millionth new PPI complaint, Natalie feels that now is the time for her to move on – as the ombudsman service itself starts out on a new set of challenges, building on the foundations for change laid under Natalie’s leadership.
“The board and I are very grateful to Natalie for her achievements as head of the ombudsman service – which under her leadership became a Sunday Times “top 100” best employer, resolving up to 2,000 consumer disputes a day.”
Deputy chief ombudsman, Tony Boorman will take charge of running the service until further notice.