Managing director Peter Darnell and operations director Barry Wilson are handing management of the business to Hamilton Hotel Partners.
Launched 15 years ago, Chartridge Conference Company began with the acquisition of the 57-room Chartridge, in Buckinghamshire, which had previously been the British Airways training centre.
The company expanded during the 90s with the addition of Hitchin Priory, in Hertfordshire, The Beeches at Bournville, near Birmingham, and Lydiard House in Swindon to the portfolio.
Darnell said: "Barry and I would like to thank all the staff, clients and suppliers for their support and loyalty during the last 15 years which has been a major contribution to the success of CCC.
"The values and standards that have become synonymous with CCC will not diminish nor will the professionalism of the teams at each venue who will continue to offer the highest level of service and quality that all CCC’s clients have rightly come to expect."
Both partners are leaving to retire, with Darnell moving to Australia.
Frank Croston, partner of Hamilton Hotel Partners, added: "We are delighted to assume management responsibility for the Chartridge Conference Company and look forward to building upon the excellent reputation of the business created by Peter Darnell and Barry Wilson. We wish Barry and Peter well as they take a well deserved rest and begin another chapter in their busy lives."