Manager Steve Bruce has left Newcastle United by mutual consent just 13 days after the Saudi Arabia-backed £305m takeover of the club was completed.
Bruce said there had been "highs and lows" and that he hoped the new owners could "take the club forward".
Graeme Jones will take interim charge of the Premier League side.
Newcastle said the appointment of a new manager "will be announced in due course".
The Tyneside club have made a winless start to the Premier League season and sit second from bottom after three draws from their opening eight games.
Bruce was appointed Magpies manager in July 2019 and achieved finishes of 13th and 12th in his two full seasons in charge.
"I am grateful to everyone connected with Newcastle United for the opportunity to manage this unique football club," said Bruce.
"I would like to thank my coaching team, the players and the support staff in particular for all their hard work.
"There have been highs and lows, but they have given everything even in difficult moments and should be proud of their efforts.
"This is a club with incredible support and I hope the new owners can take it forward to where we all want it to be. I wish everyone the very best of luck for the rest of this season and beyond."
A Newcastle statement said the club "would like to place on record its gratitude to Steve for his contribution and wishes him well for the future".
The club's next game will be at Crystal Palace at 1500 BST on Saturday, 23 October.
In an interview with the Daily Telegraph,external-link Bruce said: "I think this might be my last job.
"It's not just about me; it's taken its toll on my whole family because they are all Geordies and I can't ignore that.
"They have been worried about me… especially my wife Jan.
"I'm 60 years old and I don't know if I want to put her through it again. We've got a good life so, yeah, this will probably be me done as a manager - until I get a phone call from a chairman somewhere asking if I can give them a hand. Never say never, I've learnt that."
He added: "I wanted so badly to make it work.
"I was so proud to be manager of Newcastle United, even in the dark times, I was determined to keep going and to keep this club in the Premier League."
Games in chargeWonDrawnLostGoals ForGoals AgainstWin percentageNewcastle9728284111515228.87%Sheffield Wednesday18783271738.90%Aston Villa10246253113710745.10%Hull City20182447524823040.80%Sunderland9829284112213529.60%Wigan Athletic76261931799034.20%Birmingham City2691006910031732437.20%Crystal Palace181125422561.10%Huddersfield Town66251625807637.90%Sheffield United55221518898140.00%Bruce disappointment may come with a sense of relief - analysis
Ian Dennis - BBC Radio 5 Live senior football reporter
It was always Steve Bruce's dream job to take charge of Newcastle United but he has received a lot of criticism from the supporters, a lot of abuse which I know he feels has gone too far at times.
I think he is a realist. He would have said the takeover from a footballing sense is the best thing for Newcastle United Football Club in terms of the investment it will undoubtedly bring.
I think he is also a realist in that he knew that it would probably mean that they'd want to bring in their own manager and I think in that sense what will be, will be.
Yes he'll be disappointed, any manager would be to lose his job, but I think when he reflects there might be an element of relief as well because of the criticism and abuse that he has received, that he's no longer in the firing line.
It became quite clear at the weekend that the supporters were not going to tolerate such a position for much longer, it's very very hard for any manager to survive in those sort of circumstances.
More to follow.
