Lennox Lewis, the retired heavyweight champion said on Sunday he would be tempted to return to the ring only if he was offered a 100 million dollars after former opponent Vitali Klitschko called for a re-match.

Klitschko, 37, went back to the ring last month to be crowned world champion for the third time when he beat Nigeria's Samuel Peter to win the WBC crown and called for a re-match of his 2003 fight with Lewis Retired heavyweight champion last week.

Lewis has not fought since retaining his WBC title against Klitschko in 2003, but he says he would need to see an offer near 100 million dollars to lure him back into the ring.

The 43-year-old Lewis, who once held the WBO, IBF and IBO belts, admits he has been tempted to return after watching Klitschko beat Peter and is back in training, but the money would need to be big.

"If someone wants to pay me serious money, 100million dollars or so, then I will fight again," he says.

"I don't have to do this, I don't need the money and my legacy speaks for itself.

"But boxing needs me - the heavyweight game is so boring now.

"All the characters are gone. I would like to save my sport.

"The fights have been so dull and one-sided.

"I couldn't believe what I was watching," added Lewis after seeing the Klitschko-Peter fight from Berlin last month.

"Boxers usually come back or continue fighting for two reasons," he said.

"Either the atmosphere of the crowd or the money.

"Me? I don't need either, I'm happy as I am. But I think the sport needs me and I love my sport. And I don't like seeing it the way it is."

Lennox Lewis currently weighs around 127kgs and says he would need six months to drop to his fighting weight of 116kgs.

The former champ has only received offers of US$40m to return to the ring.

"It would have to be nearer 100million dollars to make me say yes, but there are people out there who can get that kind of money together," he said.

"There are a lot of people who would pay to see me fight again. It would be exciting, for the sport and for me.

"And if I come back, it will be to win, not play."

Lewis left in June 2003 after he won a technical knock-out victory over Klitschko when the referee had to intervene in the sixth round with the Ukrainian suffering a badly cut eye.

Klitschko, alongside brother Wladimir who holds the IBF, WBO and IBO belts, has said he wants the siblings from Kiev to hold all the world titles.