Curbishley had more than a year left to run on his current deal, but after lengthy talks with Murray and chief executive Peter Varney on Friday evening, it was decided for the continued stability of the south-east London club a change in management should be made over the summer.
Curbishley said: “I was going to stay, but I just felt I would be a little bit fraudulent. It is time now for someone else to come in here, walk around the training ground with a bit of a spring in their step, demand more from certain things, and keep this club where it is. This is the over-riding factor.”
Murray maintained it would have been too unsettling if Curbishley had remained in charge without the commitment of a new, long-term deal.
He said: “We have always looked at the club in three-year cycles, and Alan has always had at least two years left on his contract so we can plan that far ahead.
“It is very difficult when you are planning for the next 12 months. We know how fans get — if we have a tricky Christmas, they are going to be saying ‘is Alan staying? Is he going to go? Should we make changes?’
“We just scratched it all out over many hours and said ‘you know what, it is probably best if Alan has his break now and we get on with it’.”