RALEIGH, North Carolina, March 17 (Reuters) - The race is on to stage the first pre-Olympics showdown between Jamaican 100 metres world record holder Asafa Powell and American world champion Tyson Gay.

London appears to be the front-runner for a late July sprint clash with three other European cities in the mix.

"They are definitely going to race before the Olympics, maybe even twice," Paul Doyle, Powell's agent, told Reuters. "We are just trying to figure out when and where."

Mark Wetmore, Gay's agent, confirmed talks were under way but said nothing was finalised.

"Tyson has been saying since November that he wants to run against Asafa before the Olympics," Wetmore told Reuters.

Any race would be at a regular meeting.

"We are considering mostly European races....both Golden Leagues and Super Grands Prix," Doyle said.

"One, they have got the money to make this happen. Two, that's where the most media coverage is going to be."

With Gay not planning to run in Europe until after the U.S. Olympic Trials end on July 6, a mid to late July race would work best.