Avram Grant was sacked as West Ham United manager on Sunday in the aftermath of the club's relegation from the Premier League, the club announced.
"The club can confirm that Avram Grant is no longer the manager of West Ham United," said a statement released on the club website.
"First-team coach Kevin Keen will take charge of the team for the final home match of the season against Sunderland on May 22."
The east London club's owners David Gold and David Sullivan, together with vice-chairwoman Karren Brady, acted swiftly after watching West Ham relegated as Grant's team squandered a two-goal lead in their 3-2 defeat at fellow strugglers Wigan.
With only one league game to play, West Ham - who sit bottom of the table and six points from safety - are condemned to play in English football's second tier for the first time since 2006.
They had led through two goals from Demba Ba, but Charles N'Zogbia led Wigan's fightback and scored twice including a 90th minute winner after a mistake from Hammers goalkeeper Robert Green.
Gold, Sullivan and Brady were at the DW Stadium and called Grant into a meeting less than an hour after the final whistle to announce that the Israeli would be sacked.
The financial cost of relegation will be huge for West Ham, who already reportedly have the eighth highest wage bill in the Premier League.
Top-flight football is worth around Â£90 million a season in revenue and the likes of England internationals Green, Scott Parker, Carlton Cole and Matthew Upson are all likely to be sold to make up some of the short-fall.
Grant's sacking marks the end of another depressing league campaign for the former Chelsea boss, who had taken charge at Upton Park last year after leaving Portsmouth in the aftermath of their relegation from the Premier League.
But Grant, who was handed a four-year contract to replace Gianfranco Zola, endured a miserable season from start to finish and his relationship with his employers quickly became strained as West Ham struggled to climb away from the relegation zone.
Although he led the Hammers to the League Cup semi-finals and the FA Cup quarter-finals, Grant won just seven of his 37 Premier League matches this season.