A statement on the club's official website read: "West Ham United wish to announce that Glenn Roeder's contract has been terminated with immediate effect and he has been relieved of his duties as team manager.
"The board would like to place on record their gratitude to Glenn for his hard work and commitment to the club since his permanent appointment in June 2001. This was demonstrated by his desire to return to active duty so quickly after his recent illness and I am sure all supporters recognise how dedicated he was to the club.
"The board however feel that following relegation to the first division the club's best chance of returning to the Premiership at the first attempt would be enhanced by a change of manager.
"Trevor Brooking CBE will once again act as caretaker manager until such time as a permanent successor is appointed. Interviews will begin immediately and Glenn's successor will be appointed in due course."