MELBOURNE: England spinner Graeme Swann quit international and first-class cricket in an unexpected decision that became public on Sunday, just four days ahead of the fourth Ashes test and with the urn already conceded to Australia.

Once touted as potentially England's greatest spinner, the 34-year-old Swann retired with 255 wickets from 60 tests since his debut in 2008. Many critics will say he retired too early, but Swann said it wasn't a spur-of-the-moment decision.

''It's quite simple. When I came out on this trip I half expected it to be my last tour for England,'' Swann told a news conference in Melbourne, venue for the Boxing Day test. ''I was desperately hoping to win the Ashes out here again, like we did in 2010-11. But with the Ashes gone now in those three test matches ... I think to selfishly play just to experience another Boxing Day test match, a Sydney test match, would be wrong. It would be wrong for the team, it would be wrong for me.''

Earlier, he said in a statement ''this decision has been very difficult seeing as the England team has been my family for seven years now, but I feel that now is the right time to step down.'' After England lost the third test in Perth last week to give Australia an unbeatable 3-0 lead in the five-match series, Swann was forced to apologize for making comments on Facebook in which he compared his team losing the Ashes series with rape.

Swann retires as No. 2 on the list of England's leading spinners, behind only Derek Underwood (297 test wickets). But he has had a terrible series by his own standards, taking just seven wickets for 560 runs in three lopsided test losses.

He has struggled to adapt to the bouncy Australian pitches and the lack of sideways spin, and has been targeted by the Australian batsmen. He took two important wickets in the first innings in Perth to give England hope of keeping the series alive, but was clobbered in the second innings and picked up just one wicket — David Warner caught deep in the outfield for 112 for 92 runs.

''With two games to go in Australia and then a fiercely competitive summer against Sri Lanka and India I feel that it is a great time for someone else to strap themselves in and hopefully enjoy the ride as much as I have,'' Swann said. ''I don't regret a single day of my career. Every high has been celebrated with verve and vigor and every low painfully accepted as a chance to learn and improve.''

The England squad will miss Swann's sense of humor, particularly on a long and hot tour to Australia, and his willingness to challenge batsmen to take on his bowling. He was always distinguishable on the field, bowling with his sunglasses on and collar turned up.

England team director Andy Flower said Swann made an ''outstanding contribution'' to the team. ''His commitment, competitive spirit and sense of humor have been recognized and admired by team mates and supporters alike and he has played a big part in England's success over the last five years,'' Flower said. ''The dressing room will be a very different place without Graeme's unique personality and I would like to wish him all the very best for the future.''

Swann also played 79 one-day internationals for England, making his debut in 2000 at the age of 20 against South Africa in Bloemfontein. He has claimed 104 ODI wickets and in 2011 was the No. 1-ranked bowler in limited-overs international cricket. He was a key member of England's Twenty20 squad, helping England to the ICC World T20 title in 2010 and captaining the side three times in 2011.

While some on social media suggested that Swann retired because he may have been dropped for the fourth test, former England captain Michael Vaughan praised him.

''Too soon ... for Graeme Swann 2 retire but it's been a absolute pleasure watching him perform for many years.

Finger spin out of the top draw,'' Vaughan posted on Twitter. Swann is the second England player to leave the tour. After the opening Brisbane test, batsman Jonathan Trott returned to England with a stress-related illness.

Swann's departure leaves Monty Panesar as the experienced spin option for Melbourne and for the fifth test in Sydney, which traditionally favors spin.