David Moyes has resigned as Sunderland manager after one season, the club announced on Monday.
Sunderland finished bottom of the Premier League table with just 24 points after only six wins this campaign, and Moyes has now confirmed he will not stay with the team in the Championship next season.
In a club statement, chairman Ellis Short said Moyes had agreed not to settle the remainder of his contract.
"I pursued the services of David Moyes for a considerable period prior to his appointment last summer, which makes the announcement of his departure difficult for everyone concerned," Short said.
"Having worked tirelessly throughout the campaign to avoid relegation from the Premier League, David has chosen to leave the club without compensation, which is testament to his character.
"In the days ahead we will take some time for reflection, and then focus on recruitment and preseason as we prepare for our Championship campaign. We wish David well in the future."
Moyes was one of the most sought-after managers in football when he left Everton to join Manchester United as Sir Alex Ferguson's successor in 2013.
But he lasted less than a full season at Old Trafford before being sacked and was dismissed from his next post -- at La Liga club Real Sociedad -- in November 2016, almost exactly a year after joining them.
There was also controversy during his time at the Stadium of Light and he was charged by the Football Association after telling BBC reporter Vicki Sparks that she might "get a slap" over her line of questioning during interviews.
Moyes said: "I would like to thank Ellis Short and the board for giving me the opportunity to manage Sunderland and the fans for always being so passionately supportive of their club.
"I wish the players and my successor well in their efforts towards promotion back to the Premier League."