The Chelsea chief executive Ron Gourlay is to leave the club to “pursue new business challenges” after a decade at Stamford Bridge, five of them in the top job.

Gourlay has kept a relatively low profile since replacing Peter Kenyon during a period that has been Chelsea’s most successful on the pitch but also tumultuous off it.

Despite announcing an annual loss of £49.4m in December last year, Gourlay steered a course that enabled the club to comply with Uefa’s financial fair play rules and ensured stability behind the scenes despite several managerial changes.

Gourlay is expected to leave immediately, although the fact that the top executive post at the Football Association has become available with the departure of Alex Horne is believed to be merely coincidence. His departure will increase the influence of Roman Abramovich’s adviser Marina Granovskai at a club where the balance of power is continually shifting.

The Russian moved to England when he bought the club in 2003 and has acted as his representative at Chelsea since 2010. She joined the board in the summer of 2013, coinciding with the return of Jose Mourinho to Chelsea as manager and an emphasis on financial self-sustainability.

“The club, and in particular the owner and directors, wish to thank Ron for his many years of service to Chelsea and support his desire to seek new challenges,” said Chelsea in a statement.

“Ron’s efforts have helped the club to achieve its position as one of the leading football clubs in the world.”

During Gourlay’s tenure Chelsea won the Champions League for the first time and boosted their turnover and commercial income. But the board also endured criticism for their handling of the fallout from the John Terry racism affair and the instability of the Rafael Benítez era.

“It has been a privilege to have played a role in the club’s considerable achievements both on and off the pitch over the last 10 years, but I feel the time is right to move on to other challenges,” said Gourlay.

“I would like to thank Mr [Roman] Abramovich, the directors, the manager and players and all the staff for their support during my time at the club, and wish them much continued success in the future.”

Chelsea, who have not said whether Gourlay will be directly replaced, announced that chairman Bruce Buck and director Granovskaia – often described as the eyes and ears of owner Abramovich – would assume additional responsibilities.