LAUSANNE, Switzerland - Double-amputee sprinter Oscar Pistorius won his appeal Friday and can compete for a place in the Beijing Olympics.

The Court of Arbitration for Sport ruled that the 21-year-old South African is eligible to race against able-bodied athletes, overturning a ban imposed by the International Association of Athletics Federations.

CAS said the unanimous ruling goes into effect immediately.

"As you can imagine, I have been struggling to hide my smile for the last half an hour,'' Pistorius told reporters in Milan, Italy. "I can definitely say the truth has come out. We have the opportunity once again to chase my dream of participating in an Olympics, if not in 2008 then in 2012.''

Pistorius still must reach a qualifying time to run in the individual 400 metres at the Aug. 8-24 Beijing Games. However, he can be picked for the South African relay squad without qualifying.

Pistorius appealed to CAS, world sport's highest tribunal, to overturn a Jan. 14 ruling by the IAAF that banned him from competing. The IAAF said his carbon fiber blades give him a mechanical advantage.

A two-day hearing was held before a panel of three arbitrators at CAS headquarters last month. Pistorius now is expected to get invitations from track and field promoters across the world who want him to run at their meets before Beijing.

"Oscar will be welcomed wherever he competes this summer,'' IAAF president Lamine Diack said in a statement. "He is an inspirational man and we look forward to admiring his achievements in the future.''

Pistorius holds the 400-metre Paralympic world record of 46.56 seconds, but that time is outside the Olympic qualifying standard of 45.55. His training has been disrupted by the appeal process.

Even if Pistorius fails to get the qualifying time, South African selectors could add the University of Pretoria student to the Olympic 1,600-metre relay squad.

Pistorius would not require a qualifying time and could be taken to Beijing as an alternate. Six runners can be picked for the relay squad. Pistorius also expects to compete in Beijing at the Sept. 6-17 Paralympic Games.

The verdict also clears Pistorius to dedicate himself to competing at the 2012 London Olympics.

The IAAF based its January decision on studies by German professor Gert-Peter Brueggemann, who said the J-shaped "Cheetah'' blades were energy efficient.

Pistorius' lawyers countered with independent tests conducted by a team led by MIT professor Hugh M. Herr that claimed to show he doesn't gain any advantage over able-bodied runners.

CAS said the IAAF failed to prove that Pistorius' running blades give him an advantage.

"The panel was not persuaded that there was sufficient evidence of any metabolic advantage in favor of a double-amputee using the Cheetah Flex-Foot,'' CAS said. "Furthermore, the CAS panel has considered that the IAAF did not prove that the biomechanical effects of using this particular prosthetic device gives Oscar Pistorius an advantage over other athletes not using the device.''

Pistorius was born without fibulas -- the long, thin outer bone between the knee and ankle -- and was 11 months old when his legs were amputated below the knee.

Pistorius' lawyer was thrilled by the verdict.

"He simply has the chance now to compete fairly and equally,'' Jeffrey Kessler told The Associated Press. "We are particularly pleased that the decision is unanimous.''