Nigel Pearson has left his position as Derby County manager by mutual consent after less than five months in charge.
Pearson, 53, was suspended last month pending a club investigation into his "behaviour" following a heated exchange with owner Mel Morris.
The Rams, who lie 20th in the Championship under temporary manager Chris Powell, said "any disciplinary process had now ceased".
Pearson said he was "disappointed" his tenure had come to a "premature end".
In a statement released by the League Managers Association, Pearson added: "The speculation in some areas of the media has not made the separation a smooth one, and my suspension period has been difficult for both myself and family.
"I would like to take the opportunity to thank my colleagues who supported me during my short time at the club."
Morris had described Pearson's appointment as "perfect" - but the Rams only won one of their nine league matches during the former Leicester manager's reign.
Morris told the players of Pearson's suspension just three hours before their league match against Cardiff City on 27 September, with assistant boss Powell overseeing a 2-0 victory.
A club statement said: "The board will now turn their attention to appointing a new manager as soon as possible."
Analysis - Powell a sensible choice
BBC Radio Derby's Owen Bradley
Nigel Pearson's departure was inevitable from the moment he was suspended.
It was always unlikely he could come back following a heated exchange with owner Mel Morris, although the exact details of that confrontation will no doubt stay private.
Chris Powell looks to be the strong favourite to get the job and seems a sensible choice. He is a former player who knows the club and the players, and understands the demands of working at Derby County.