Ivan Gazidis will step down as CEO of Milan when his contract expires next month, the reigning Serie A champions have announced.
The 58-year-old had held the position at San Siro since December 2018 following a decade as part of Arsenal's boardroom.
During Gazidis' four years at Milan, the club ended an 11-season wait for the Scudetto, returned to the Champions League and improved their financial figures.
Amid recent speculation regarding his future beyond this year, the Rossoneri confirmed on their official website on Wednesday that Gazidis will depart on December 5.
Commenting on the announcement, Milan chairman Paolo Scaroni said: "On behalf of everyone associated with AC Milan, I would like to say a heartfelt thank you to Ivan for his passion and dedication, as well as the significant contribution he has made to the health and success of this football club, representing and enhancing the core values for which it stands.
"As I said during our recent shareholders' meeting, it is very easy to be the chairman of an organisation which has a CEO of the quality of Ivan Gazidis.
"I would also like to personally wish him some peaceful and well-deserved time with his family and every success in his next professional chapter."
Gazidis was diagnosed with throat cancer in July 2021 but returned to his daily duties with Milan following a short period away.
And the South African has credited the Italian giants for helping him to cope during a hugely challenging period on a personal level.
"After four wonderful, challenging years I will be leaving Milan," he said in a statement. "I owe so much to this club, its people, its fans and to this city, that literally saved my life.
"If the club is in a better position now than when I arrived, it is entirely due to the work of those I have been surrounded with, from our ownership, to our chairman, our head coaches, their coaching staffs, our sporting directors, our players and every young boy or girl with dreams in our academies, our scouts, analysts, medical and support staff, our senior management team and all of the extraordinary people who live for and give everything they have for this club.
"I have been privileged to work with them all. I have no doubt that this foundation and the people we have in place in every position will take the club to new levels in the years ahead.
"Finally, I want say a personal thank you to our fans. Our fans have carried their club (and me) through some difficult times through their belief and their strength.
"I will hold in my heart forever the way they showed their support to me when I was not well. They deserve every good thing. I may leave the club, but the club will never leave me."
Milan, who trail Serie A leaders Napoli by eight points with one game to go before the World Cup break, intend to announce Gazidis' successor "in due course".