President Olivier Letang is leaving Stade Rennais with immediate effect, the Ligue 1 club said without elaborating on Friday.
"Francois-Henri Pinault, owner of Stade Rennais since 1998, thanks Olivier Letang for his commitment and his contribution to the club's trajectory since 2017," Rennes said in a statement.
In the club's statement, Letang was quoted as saying he was leaving "reluctantly".
Board president Jacques Delanoe has been appointed on an interim basis.
Under Letang, Rennes won the French Cup last year, their first trophy in 48 years.
The Brittany side are third in the Ligue 1 standings.
(Reporting by Julien Pretot; Editing by Christian Radnedge)
