Daily Mail and General Trust has launched the search for a new chief executive after Martin Morgan announced plans to retire at the end of the year.
Morgan first joined the company, which publishes the Daily Mail, Mail on Sunday and Metro newspapers, in 1989, rising to chief executive in 2008.
Chairman Lord Rothermere said: "Martin will continue to provide strong leadership for the group, as he has done so successfully in the last seven years as chief executive."
The group said it will begin a "thorough" process to recruit Morgan's successor, searching internally and externally.
Media experts at Liberum said a change at the top may herald a shake-up at DMGT.
They added: "This departure gives DMGT an opportunity to review its current assets, such as its stake in Euromoney, its events business and the Mail Online."
Morgan joined DMGT from Reed International, where he held a number of managing roles, including heading up Reed's travel and medical interests.
He said: "Since joining the group in 1989, I have seen significant change, particularly with the growth of our B2B operations, the development into a truly global company and the successful transition from print to digital.
"I am looking forward to my final year as chief executive – executing on the clear priorities set for 2016 and shaping the group for growth for the next decade."
Picture shows Morgan in a DMGT YouTube video