Sam Allardyce will leave West Ham United after the club chose not to renew his contract at Upton Park.
In recent months, it has been widely speculated that the 60-year-old would depart the club at the end of his existing deal, and minutes after the conclusion of their defeat to Newcastle United, the Hammers confirmed that they would appoint a new boss.
In a statement, joint-chairmen David Gold and David Sullivan said: "We would like to start by thanking Sam Allardyce for his valuable work since arriving at the Boleyn Ground four years ago.
"He leaves the club in a considerably better state then when he arrived and, for that, the board are truly grateful.
"However, we have made the decision not to renew his contract, so we now have the chance to appoint a new manager with a new philosophy to lead us into two of the most exciting years in our great club's history.
"Our target is to recruit a manager that will build a team capable of saying a fitting farewell to the Boleyn Ground next year and do justice to the outstanding surrounds we will call home from August 2016.
"We have already been impressed with the quality of candidates that have expressed an interest in the role and fully expect to appoint a manager with the credentials to take this club on to new heights.
"From our point of view, there isn't a more exciting job in the Premier League at present."
Allardyce, who guided West Ham to 12th place in the Premier League table this season, leaves the club having won 69 of his 181 matches in charge.