Newcastle United say manager Rafael Benitez will leave the club when his contract expires on 30 June.
The Magpies finished 13th in the Premier League last season as Spaniard Benitez, who took over in March 2016, secured the club’s top-flight status.
“We have worked hard to extend Rafa’s contract over a significant period of time,” said a Newcastle statement.
“However, it has not been – and will not be – possible to reach an agreement with Rafa and his representatives.”
The statement added: “The process to appoint a successor will now begin.”
Former Swansea boss Garry Monk and current Manchester City assistant manager Mikel Arteta are among the early favourites to replace Benitez, along with Jose Mourinho and Gennaro Gattuso.