Alan Curbishley will leave Charlton at the end of the season after close to 15 years in charge at The Valley.
Curbishley was considered for the England job but his exit was confirmed by plc chairman Richard Murray on the pitch at The Valley ahead of the game against Blackburn.
Murray said: 'We sat down yesterday to have a chat and we both decided it was best if Alan left at the end of the season.'
Murray revealed the decision came after Curbishley told Murray he did not intend to extend his contract beyond next summer.
Murray said: 'Fifteen years ago we started on a journey which saw us return here to The Valley in 1992 and then embark on a period of sustained progress and success on and off the field.
'Throughout the entire period Alan Curbishley has been the manager of this great club.
'He has given us memories that will live with us all forever.
'Promotion to the Premiership in 1998 followed the most dramatic play-off final ever to take place at Wembley Stadium - 4-4 against Sunderland and 7-6 winners on penalties.
'In 2000 we won the First Division Championship in spectacular style.
'Next season we will start our seventh successive season in the Premiership - the best league in the world.
'Alan has masterminded all this success and deserves our total admiration.
'Yesterday I sat down with Alan to discuss our plans for the future and Alan was as honest as he has always been throughout his time at Charlton and told me he would not be extending his current contract.
'We enjoy a fantastic relationship and Alan only wants to do his best for Charlton for whom he has a deep affection.
'We both agreed that it would therefore be in the interests of the club and Alan if we parted company at the end of the current season. We do so as the best of friends.
'Alan will manage a Charlton team for the last time at Old Trafford next Sunday and today is his last match in charge of a Charlton team at home.
'When Alan emerges from the tunnel today I would ask each and every one of you to stand and pay tribute to a remarkable man and leave him in no doubt of the genuine affection you all hold for someone who has done so much for our football club and is in my opinion the greatest football manager this club has ever had.'