Jose Mourinho has left his job as Manchester United manager after two and a half years in charge.
The Portuguese, 55, won the League Cup and the Europa League at Old Trafford.
But United are sixth in the Premier League, 19 points behind leaders Liverpool, who beat them 3-1 on Sunday.
“A caretaker-manager will be appointed until the end of the season while the club conducts a thorough recruitment process for a new, full-time manager,” United said in a statement.
“The club would like to thank Jose for his work during his time at Manchester United and to wish him success in the future.”
A new caretaker manager will be appointed until the end of the current season, while the club searches for a new full-time manager.
Manchester United have made their worst start to a league season since 1990-91 and sit sixth in the Premier League.
A poor start to the Premier League season has seen United slip 19 points behind the leaders, Liverpool, and fall off the pace in the hunt for a top-four place. They have won only once in six league matches, drawing during that sequence with struggling Southampton and Crystal Palace.