Alan Curbishley has resigned as West Ham United manager.
Curbishley tendered his resignation on Wednesday and it was accepted by owner Bjorgolfur Gudmundsson.
The final straw for the 50-year-old had been the enforced sales of Anton Ferdinand and George McCartney.
Curbishley said decisions had been made "without involving me", amounting to "a breach of trust and confidence meaning I had no option but to leave."
The former West Ham player, who succeeded Alan Pardew as manager at Upton Park in December 2006, added: "The selection of players is critical to the job of manager and I had an agreement with the club that I alone would determine the composition of the squad.
"I started my West Ham career when I left school in 1974 and have remained a lifelong fan.
"I have been incredibly proud to manage such a great club and my decision to resign has been very tough.
"Nevertheless, I wish the club and the players every success in the future."
A West Ham statement said the club had accepted Curbishley's resignation "in the best interests of both parties".
It continued: "We wish Alan all the success in the future. A shortlist of candidates is being drawn up and an announcement will be made in due course about the new manager."
West Ham also moved to justify the summer departures of Ferdinand and McCartney to Sunderland, stating that the sales were "right for the club" and "based on our best long-term interests".
"In the past week, agreement could not be reached with Ferdinand on a new contract to replace his original deal that had just two years left to run," the club added.
"McCartney handed in a formal written transfer request after failing to resolve his personal reasons for wanting a move away."