Financial Ombudsman Service chief executive Natalie Ceeney is stepping down from the role after four years with immediate effect.
Deputy chief ombudsman Tony Boorman will take the helm at the FOS until further notice.
FOS chairman Sir Nicholas Montagu says: “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 payment protection insurance.
“Natalie feels 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.”
Ceeney says: “I feel very proud of the difference we have made to society and the faith we have helped to restore in the importance of financial services.
“I feel similarly proud of how well the ombudsman has responded to the challenges of the PPI misselling scandal, having to triple in size to handle the unprecedented volumes of complaints we received.
“But most of all, I have thoroughly enjoyed my time at the ombudsman, working with the hugely talented people who make the service unique and special.”
Investment Quorum chief executive Lee Robertson says: “Natalie Ceeney has done a fairly decent job during her time at the FOS in difficult circumstances.
“This is a high profile role and there are lots of parties with competing interests, which means it is very difficult to keep everyone happy.”