Usain Bolt should concentrate on retaining his Olympic 100 and 200 metres titles before considering a move into other events, nine times Olympic champion Carl Lewis said on Tuesday.

Bolt emulated Lewis by winning gold medals in the 100, 200 and 4x100 metres relay in a single Games at the 2008 Beijing Olympics. However, the American also won four consecutive long jump titles.

The Jamaican, who will be the hottest ticket in town at the London Games next year, said recently he was considering the long jump and also the 400.

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"I think it's a big enough challenge right now for Usain to try and win the 100 again," Lewis told Reuters at a 2012 ticket launch alongside London's Tower Bridge.

"For his sake it would be wonderful if he could move into other events, but long jump? He would find that tough.

"People have to realise that I was a long jumper who sprinted. It's a lot more difficult to come from the sprints to the long jump. If it wasn't so, a lot more sprinters would become long jumpers.

"He's also talking about the 400 metres which would be a more natural progression. If he does, good luck to him."

Bolt, 24, the quickest man ever in the 100 and 200 metres, will be the man to beat at the world championships in Daegu this year where he will also be defending both titles.

Dominant as he is, however, Lewis urged caution for those already pencilling him for a golden haul in London.

"No matter who you are, the thing at the Olympics is that anything can happen," the 49-year-old Lewis, his hair now flecked with grey, said. "I should know because I went to four of them and something different always did.

"And he sure has a great rival right now in Tyson Gay.

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"That's great for the sport, particularly the fans. I won a lot of 100s but I remember the rivalry I had with Mike Powell in the long jump when he came along and jumped 29 feet."

Powell leaped 8.95 metres (29 feet 4-1/2 inches) at the 1991 Tokyo world championships to beat Lewis to the gold medal and break Bob Beamon's 1968 world record.

Lewis said Bolt's stunning performances since 2008 had raised the bar considerably in the sport.

"When I was competing I didn't personally need rivalries I just focused on my times and distances and that helped me stay out in front," he said. "But it helped the other guys around me because they knew that Carl was not going to be standing still and they needed to get better and better."

Lewis is relishing the prospect of his fourth Olympic Games as a fan and believes London will put on a great show.

"I'm going through the list of events and checking which sports I've not seen before," Lewis said. "I've been to badminton, rowing, handball and ping pong...I think in London I want to go and see the archery."