Premier League strugglers Reading have confirmed the departure of manager Brian McDermott.
McDermott, 51, led the club to promotion last season, but four successive Premier League defeats have left them four points adrift of safety.
A Reading statement said: "The search for a successor starts immediately. It is hoped a new manager will be in place as soon as possible."
Academy head Eamonn Dolan is in charge of the first team in the interim.
The Royals also confirmed first-team coach Nigel Gibbs had also left the club he joined in 2006.
McDermott joined Reading in 2000 as a scout/coach working under Alan Pardew and Steve Coppell.
He was named caretaker manager in 2009 following the sacking of Brendan Rodgers, before being appointed permanent manager.
McDermott just missed out on promotion to the Premier League in his first season in charge of Reading, reaching the play-off final but losing 4-2 to Swansea City.
However, a run of 15 wins from 19 games towards the end of last season secured the Championship title and the Royals' promotion to the top flight for only the second time in the club's history.
In May 2012, Reading were taken over by Russian tycoon Anton Zingarevich, who acquired 51% of the club, and also announced a reshuffle in the boardroom.
Reading struggled for the first half of this season, winning only two Premier League games, but they showed signs of improvement in 2013 with four successive victories in all competitions, including two in the top flight, and McDermott was named the January manager of the month.
However, defeats by Stoke, Wigan and Everton, followed before a 2-1 loss at home to relegation rivals Aston Villa at the weekend, left Reading 19th in the table, level on 23 points with bottom club QPR.
Dropping out of the Premier League would mean the club would miss out on a share of a new TV deal worth about £5bn across three years from August.
The Reading statement added: "[Reading] owner Anton Zingarevich wishes to place on record his thanks to Brian who had achieved great success with the club since taking over as Manager in December 2009.
"Brian gained promotion to the Premier League last year for only the second time in the club's history thanks to a remarkable run at the end of last season.
"However, in our current situation, owner Anton Zingarevich felt that a change was necessary."
Reacting to the news, Reading striker Noel Hunt wrote on Twitter: "Want to say thanks to Brian for everything he did for me especially. He's been a great manager, man and friend to me and will be missed!"
Former Reading captain Aidy Williams added: "I'm very surprised, more by the timing than the actual events.
"I'm disappointed. I've known Brian for well over 10 years. His pride will be dented, he's a very passionate football man and has done his apprenticeship. But he can hold his head up high.
"He won the Championship against all odds, but in all honesty he was fighting a losing battle with budgets."
Current Reading player and BBC Radio 5 live pundit Jason Roberts said: "I'm in shock and I'm sad because he brought me in. I'm disappointed for him, the players and the club.
"I'd like to put on record our thanks to the manager for what he achieved. He achieved so much.
"Our budget was nowhere near the top ten so for us to win the league was a massive achievement. With nine games to go we still have an opportunity and it's now time to take stock.
"As a player we have to just get behind the new manager, we all want the same thing - to stay in the Premier League."