Chelsea have announced the shock news that chief executive Peter Kenyon will be leaving the club at the end of October.
Kenyon, who relinquished his role at Manchester United when agreeing to join Chelsea in the early months of Roman Abramovich's reign in 2003, will continue to represent the club as a non-executive director and at various European committees.
However, his day-to-day running of the West London side will come to an end on October 31, Chelsea confirmed on Wednesday afternoon.
"I am extremely proud of my time at Chelsea and of the friendships I have forged with everyone here," Kenyon told the club's official website. "I have been in football for 15 years and I can say with great certainty and pleasure the experience at Chelsea is one of the best I have had.
"When I joined Chelsea it was an incredible challenge and together with all the staff, the players, the board and Roman, I think we have really built a club, in a relatively short space of time, that can be in the forefront of European football for many years to come. That is a major achievement.
"I am also delighted that our relationship is not ending and I can continue to make a contribution to keeping Chelsea in that position and to go back to visit friends. I intend to take a little time off before considering what I do next but I am certain I have at least one more major challenge left in me."
Abramovich's success in luring Kenyon to Stamford Bridge from United was one of the early indications that the Russian's takeover would signal a real change in the balance of power in English football, as he recruited the former Umbro chief executive to build the club's global brand and establish their position as one of England and Europe's elite clubs.
Along with Abramovich, Kenyon played a key role in the removal of manager Claudio Ranieri, replacing the Italian with Jose Mourinho following his success in winning the Champions League with Porto in 2004. Under the Portuguese, Chelsea won back-to-back Premier League titles.
As well as orchestrating some of the biggest transfers in British football history, including the then record signing of £30 million Andriy Shevchenko from Milan in 2006, Kenyon also helped to usher the club through turbulent times following the departure of Mourinho in September 2007, the sackings of Avram Grant and Luiz Felipe Scolari and, this summer, the appointment of current manager Carlo Ancelotti.
In recent weeks Chelsea have come under fire for their recruitment of Gael Kakuta, incurring a transfer ban from FIFA for inducing the youngster to break his contract with Lens, but Kenyon strongly defended the club's conduct ahead of an appeal to the Court of Arbitration for Sport. The current chief executive will not be in charge when the appeal is heard though.
Chelsea chairman Bruce Buck paid tribute to Kenyon's work at Stamford Bridge over the past six years, stating: "Without his football knowledge and business acumen Chelsea would not be where we are today.
"Everyone at Chelsea thanks him for that contribution and although he will not be with us on a permanent basis he will have an important role to play as a non-executive director and in the various roles he holds in European football bodies. Whatever his next permanent job we wish him the best of luck in the future."