Enterprise Inns operations director Gordon Harrison will retire from the pub group in September.
Harrison, 48, leaves the company after 15 years and will not be directly replaced.
His departure from the board will see it reduced from four to three members.
Customer services director and board member Simon Townsend will be promoted to the role of chief operating officer and take over most of Harrison's work.
Ted Tuppen, chief executive of the 8,600-strong tenanted and leased pub group, said: "I would like to thank Gordon for his outstanding contribution to the successful growth of the company over the past 15 years."
By Tom Bill