Eddie Mitchell has stepped down as chairman of AFC Bournemouth and sold the 50% stake owned by him and wife Brenda to co-owner Maxim Demin.
Mitchell first bought into the club as part of a five-man consortium in June 2009 and was installed as chairman.
Russian businessman Demin joined him as co-owner in October 2011, when he obtained the other 50% of the club.
"The outcome will help enable the club to find the financial investment that it needs," Mitchell's statement read.
"We would both like to wish our partners, board members and successors the very best for the future and we sincerely hope that the club continues to enjoy its recent success going forward."
Bournemouth have undergone major changes on the field during Mitchell's tenure, particularly since the Demin investment, which culminated in promotion to the Championship at the end of last season.
As well as signing winger Matt Ritchie for £500,000 last term, their financial backing saw the Cherries break the club's transfer record by paying Crawley £800,000 for Matt Tubbs in January 2012, a deal which was eclipsed by last month's signing of South African Tokelo Rantie from Swedish club Malmo for an undisclosed fee.
It is a different scenario to the one which greeted Mitchell on his arrival, with the club facing a winding up petition from HM Revenue & Customs and the team having finished 21st in League Two the previous season.
The consortium quickly stabilised the club, and after winning promotion to League One in their first season, Bournemouth reached the play-offs 12 months later.
The return of manager Eddie Howe from Burnley in October 2012 was the catalyst for last season's promotion and a return to the second tier of English football for the first time since 1989-90.