Turner, who joined Countrywide in 2006, has agreed to stay on as non-executive chairman once a replacement has been found.
David Watson, currently the interim chairman, will then become deputy chairman and senior independent director.
Turner said: “Over the course of the last seven years, I have been fortunate to be CEO of Countrywide plc.
“During this time, the Group has been through quite a journey, both internally through a significant transformation programme, and externally, including a take private and return to public markets, all while operating during a prolonged downturn in the UK property market.
“I take great pride that as a plc, Countrywide is operating so well following successful results for 2013 and, after careful consideration, I have decided that now is the right time for me to step down from my role as CEO. I am delighted to be assuming the role of chairman and look forward to continuing to work with everyone at Countrywide, who I respect and admire greatly."
Watson added: “After careful consideration and following discussions with a number of our major shareholders, the Board has asked Grenville to become chairman once the new chief executive is in place and we have commenced the process of finding a replacement.
“This will ensure we retain Grenville’s extensive experience and qualifications while providing important continuity for the benefit of the company and its entire shareholder base.
“Grenville has been an extraordinary leader for the Group and the Board and I are confident that he will make a very able chairman.
“The Group and its shareholders owe a huge debt to him, and to the senior management team who have worked so closely with him over the years. I know they will continue to support the new CEO through the next chapter of Countrywide’s journey.”
