Wigan chairman Dave Whelan is poised to raise more than £50million by selling some of his stake in JJB Sports.
The sports retail company said their founder had decided to sell the shares for personal financial reasons and that he remained committed to the business.
Whelan will offload up to 20.5million shares, equivalent to 8.6% of the company. At Thursday night's closing price, the shares were worth £52.9million.
The move will reduce the holding Whelan and his family have in the company to around 29%. He has undertaken not to sell more shares for at least 12 months.
Whelan stood down as chairman of the retailer in July 2005 as part of plans to spend more time with his newly-promoted Premiership team.
He stopped short of severing all ties with JJB by accepting an executive directorship, ensuring he has continued to play a part in the day-to-day running of the company he set up in 1971.
Born in Bradford in 1936, Whelan turned his attention to retailing after injury cut short his football career. He is best known for breaking his leg in the 1960 FA Cup Final when his team, Blackburn, played Wolves.
He went on to form JJB Sports after acquiring a single sports store in Wigan, which had been trading since the early 1900s.
In the period since 1978 he has overseen its expansion into a 430-strong chain of stores and the UK's largest sports retailer, with an estimated 25% market share. It also runs health clubs and indoor soccer centres.
Mr Whelan also has a controlling interest in Whelco Holdings, which operates the JJB Stadium in Wigan, Wigan Athletic and Wigan Warriors.