World heavyweight champion Lennox Lewis has confirmed his retirement from professional boxing.
The 38-year-old Briton has not fought since June last year, when he stopped Vitali Klitschko after a tough fight.
He has been under pressure to decide on his future and the World Boxing Council set him a 1 March deadline to confirm a rematch with the Ukrainian.
His decision means that he is the first reigning heavyweight champion to retire since Rocky Marciano in 1956.
"This is a special day in my life," said Lewis.
"I would like to announce that 21 June 2003 was my last fight as a professional boxer."
The 38-year-old Lewis has fought just twice in the past 26 months, knocking out former undisputed champion Mike Tyson in eight rounds in Memphis in June 2002 and the stopping of Klitschko.
Lewis won the Olympic superheavyweight title for Canada in Seoul in 1988, but returned to Britain, where he was born, to turn pro. He has won 41 of his 44 pro fights.
"When I first started boxing I realised there was no straight road to the world title." he said.
"I realised there were bumps and potholes and curves but there is no straight way to becoming heavyweight champion of the world.
"I learnt on this trip that if you lose that doesn't mean the end of the boxing career.
"It's not easy being heavyweight champion, even harder to keep it and stay at the top.
"If you can't give 110% then you shouldn't do it - I've given 110% in my sport.
"I'm proud to be heavyweight champion."
Lewis said he was excited by the up-and-coming fighters in the heavyweight division.
"I am looking forward to seeing that next era of boxing - fighters like Audley Harrison and the Klitschkos," he said.
"I'm probably going to wish I was in there.
"It's been great honour to be the standard bearer for boxing in the last decade.
"Let the new era begin."
Lewis is to move into management with the SEM promotions agency, with which he had links while still boxing.
Lewis said: "I have got a new life and a new future and there is definitely more to Lennox Lewis than just boxing.
"I am definitely going to miss boxing because it is something which is in my
blood and will be for a long time.
"But I've got so much knowledge to give to other boxers and athletes and it would be waste to keep it all to myself."