Steve Coppell has resigned as Reading manager after Tuesday's defeat by Burnley denied the Royals a place in the Championship play-off final.
The 53-year-old took charge in 2003 and guided Reading into the Premier League three years later but they were relegated in 2008.
Coppell's men lost 2-0 to Burnley on the night and 3-0 on aggregate.
"Following our play-off exit I feel it's the best thing, for both the club and myself, for me to leave," he said.
"I have thoroughly enjoyed my time as Reading manager and would like to thank everyone connected to the club for the support I have received."
Coppell and Reading chairman John Madejski will hold a news conference at 1100 BST on Thursday.
"The club needs freshening up"
Reading were looking to make an immediate return to the Premier League following their relegation last season and made a superb start to the campaign.
But their form fell away in the final three months of the season and their last win at home was on 27 January.
On Tuesday, second-half goals from Martin Paterson and Steven Thompson ended Reading's hopes and ensured Burnley will take on Sheffield United at Wembley on 25 May for a place in the top flight.
Coppell refused to comment on his future during the post-match press conference but confirmed his departure a few hours later.
"I am very disappointed to confirm that Steve has decided to step aside as our manager, but I respect his wishes," said Reading chairman Sir John Madejski.
"I would like to thank Steve sincerely for everything he has done for Reading over the last five-and-a-half years, which has been the most successful period in the club's history."
Home form cost Coppell - Williams
In his first two seasons at the Madejski Stadium, Coppell led Reading to ninth and then seventh, on both occasions missing out on the play-offs on the season's final day.
But in the next campaign the Royals were promoted as champions, collecting a record 106 points and scoring 99 goals along the way.
Reading ended their first season in the top flight only one place shy of a Uefa Cup spot, with Coppell earning the League Managers' Association manager of the season award for the second successive year.
But Coppell, a former Crystal Palace, Manchester City, Brentford and Brighton manager, could not prevent Reading's final-day relegation in 2008.
His agent Athole Still revealed Coppell initially decided to leave the club that summer but eventually changed his mind.
As a player, Coppell had a successful eight-year spell with Manchester United and made 42 appearances for England.
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