Colchester have announced manager Geraint Williams is departing the struggling League One club by mutual consent.
The Welshman, who took over from Phil Parkinson two years ago, is leaving the Us lying second from bottom following Saturday`s 3-0 defeat by MK Dons.
In statement on the club`s official website, chairman Robbie Cowling said: ''It is with considerable regret that I have to report that manager Geraint Williams will be leaving his post as the first-team manager of Colchester United.''
Cowling said: ''Following the 3-0 defeat against MK Dons and the manner in which the team was defeated, it was mutually agreed between the board and Geraint that both parties would be best served if Geraint stood down from his role and a new manager was appointed.
''In my opinion Geraint was badly let down on Saturday by some of his players, who failed to play for him, some of our supporters, who failed to support him, and by myself for failing to back him publicly before it was too late.''
Williams, 46, was Parkinson's assistant when they led the club to promotion to the Championship in 2006.
The former Wales, Ipswich and Colchester midfielder was then named manager after Parkinson quit for Hull, and guided the Us to their highest-ever finish of 10th in the second tier.
However, the loss of key players saw the club relegated the following season and they have yet to win a game at their new Community Stadium this term.
''In no way do I hold him responsible for last season's relegation,'' added Cowling.
''The club could not give him the funds and the facilities required to maintain Championship football.
''However, he proved without a doubt, during the one season where he did have a team capable of competing, that he could manage very successfully at that level and, if given the right tools, even higher.''
Colchester assistant-boss Kit Symons has taken the role of caretaker manager and has thrown his hat into the ring for the full-time role.
"Being a manager is something I have always wanted to do. I had a spell at Palace when I was in charge there and I really enjoyed it," Symons told the club's official website.
"It certainly wasn`t on my agenda when I came here as Geraint`s assistant, because he was someone I knew, liked and respected and I have enjoyed working alongside him.
"The results have been disappointing and we have all been frustrated by them, but this is an opportunity for myself and one I aim to take."