Manager David Moyes will leave West Ham at the end of the Premier League season, the club have confirmed.
It comes after BBC Sport's Guillem Balague reported that former Wolves boss Julen Lopetegui had agreed a deal to replace Moyes.
Moyes, 61, had come under increasing pressure after a poor run of results, including Sunday's 5-0 defeat by Chelsea.
"I have enjoyed four and a half brilliant years at West Ham, and the club is in a stronger position than when I returned back in 2019," Moyes said.
The Scot took over for his second spell at the club in December 2019 and guided the Hammers to Europa Conference League success last season - their first major trophy for 43 years.
But his side have won just one of their past 10 games across all competitions, losing five, and, sitting ninth in the Premier League, are likely to miss out on a fourth successive season in Europe.
"When I joined West Ham for a second time, the club was one place above the relegation zone, and it has been a terrific journey to have achieved three consecutive seasons in Europe," Moyes said.
"I would like to thank all the players for their support, and all the success they have achieved, over the last four and a half years."
While nothing has been signed yet, former Spain and Real Madrid boss Lopetegui is close to making a return to management with the Hammers, following his departure from Wolves in August last year.
Though West Ham confirmed the search for Moyes' successor had begun, they said they would not comment until an appointment was made.
The club's joint chairman David Sullivan said Moyes had been "responsible for a period of great progress and success" in West Ham's history.
"David has been an absolute professional to work with and he will leave with our greatest respect and good wishes - he deserves to be held in the highest esteem for the service he has given to West Ham United, and we wish him every success in the future," Sullivan said.
"By making this announcement now, it allows David to get the send-off he deserves from the West Ham supporters and for us all to show our appreciation to him at our final home fixture of the season against Luton Town on Saturday."
- BBC