Fans cheer Michael Jackson at the 02 arena
By Ian Youngs
Music reporter, BBC News
Michael Jackson's series of 10 concerts at London's O2 arena in July will be "the final curtain call", he has said.
He told fans at the venue: "This is it. I just want to say that these will be my final show performances in London."
The pop superstar, 50, may take the show around the world - but that would be his last tour, his promoter said.
The star made a five-minute appearance in front of hundreds of screaming fans to announce the 10 London dates, which will earn him more than $50m (£35m).
His first words to fans were: "I love you so much.
"This will be it. When I say this is it, it really means this is it," he added.
"I'll be performing the songs my fans want to hear. This is the final curtain call."
The first concert at the 20,000-capacity venue will be on 8 July, with tickets costing between £50 and £75. They go on general sale on 13 March.
The star will put on a "big budget, grand, highly technical, incredible show", according to Randy Phillips, chief executive of promoter AEG Live.
"Michael Jackson is a perfectionist so it's going to be amazing," Mr Phillips told BBC News. "He'll try a lot of new things."
Asked whether the London dates would be his last ever performances, Mr Phillips replied: "These will be the last shows in London.
Michael Jackson arrived an hour and a half late, but fans did not mind
"Whether he will go on from here around the world... this will be his last tour. All he's agreed to are the London shows at this point."
The star was "in great shape" for the dates, he said.
"He's passed an extensive four-hour physical with independent third party doctors selected by the insurance carriers. He's in incredible health."
Mr Phillips added that AEG had a "broader relationship" with Jackson, which could involve a new 3D film based on Thriller as well as future concerts.
The three-and-a-half year plan could earn Jackson more than $400m (£283m), he predicted.
The singer had been due to appear at the O2 at 1600 GMT, but he only left his central London hotel at that time and arrived an hour and a half late for the announcement.
Several hundred fans waited at the O2 to see him, and said they were not disappointed by his brief appearance.
Peter Scott from London said: "It was brilliant, awesome, seeing the man in the flesh again. He looked in fine shape, looked fit, I reckon he can handle the 10 [shows].
"And they're going to put on more concerts, definitely. Ten isn't enough."
Mr Scott said he would come to "as many as possible", adding it was the "credit crunch - but I'll find a way, somehow".
And he did not believe Jackson would really retire from the stage.
"Never say never," he said. "The man can always change his mind. When he sees the demand, he's going to have to perform next year and the year after that for eternity."
Michael Jackson was introduced by TV host Dermot O'Leary
Another fan, Fiona Hetherington, 37, from Ewell in Surrey, said the experience of Jackson's announcement was "was pretty surreal".
"It was amazing to see him," she said. "Very few words. A man of few words, but amazing.
"I actually went very hysterical. I was standing next to a lookalike and a guy who has the moonwalk world record."
The singer "looked really, really well", she added. "And I can't wait to see him in July."
Some wore T-shirts bearing his image, while others clutched memorabilia.
The O2 is the venue where Prince played for 21 nights in 2007, and where Britney Spears is performing for eight nights in June.
Jackson last toured 12 years ago. In 2006, he performed at the World Music Awards in London, but disappointed fans by singing just a few lines of We Are The World.
Stories about personal, health and financial problems have circulated in recent years. He was cleared of child abuse after a four-month trial in 2005.