Chelsea football club on Monday announced that Bruce Buck, who has served as chairman since 2003, will be stepping down from his role, the club said in a statement.
The 76-year-old's role will come to an end on June 30 but he will still support the club as an advisor.
Chelsea was sold last month for 2.5 billion pounds ($3.2 billion) -- the highest price ever paid for a sports team - to a consortium led by club co-controlling owner Todd Boehly.
"Bruce has led Chelsea Football Club to the highest levels of international and domestic football, while also developing one of the most active social responsibility projects in sport," said Boehly.
"We thank Bruce for his service and his commitment to the Club," he added.
"During Buck's chairmanship, Chelsea solidified its position as one of the world's elite football clubs and a globally recognised brand. During his tenure, the men's team earned 18 major trophies (more than any other English club) while Chelsea FC women won 12 major trophies," the club said in a statement.
"I am proud to have helped Chelsea realize great success on the pitch and make a positive impact in the community," said Buck.
"Now is the right time to step down and let new ownership build on the strong foundations we have in place. The owners have a compelling vision for Chelsea's future, and I look forward to helping them achieve it in this new role alongside our incredible staff, players, coaches and supporters," he added.
The club also grew its commercial revenues significantly, established world class training facilities at Cobham, and developed one of the best youth academies in football.
In 2010, Buck, as trustee and chairman, helped establish the Chelsea FC foundation, which supports a broad range of initiatives including increasing access to youth athletics, hosting education and employment programmes, and leading anti-discrimination campaigns.
