It slammed a bobsleigh track and two ski jumps that slice down two mountainsides, but praised organisers for using clean fuel and recycling waste.

"It could have been better, but it could have been a lot worse," said Sergio Savoia, director of the WWF's Alpine programme.

Roberto Saini, environmental director at the TOROC organising committee, said: "We were rather pleasantly surprised. They have delivered a largely positive assessment."

The WWF called the 5-metre (16-foot) high Olympic flame, which will be lit at the opening ceremony on Friday evening and burn until the end of the Games on Feb. 26, "a kind of mockery, a monument to waste".

The flame, which will flicker atop a 57-metre (187-foot) high torch, will burn some 3 million cubic metres (105 million cubic feet) of gas during the Games - enough to supply a town of 3,500 people for an entire year, it said.

NEGLIGIBLE IMPACT

But Saini said WWF had overestimated the amount of gas, and the methane would have a negligible impact on the environment.

He acknowledged that by their nature the 1,435-metre long bobsleigh and twin ski jumps would have an impact, but that they were designed to hug the mountain and any trees cut down were offset by plantings elsewhere.

Still the WWF, like other environmental groups, said it would have been better to use existing bobsleigh and jumping facilities in neighbouring France rather than bequeath yet more tracks to the relatively restricted circle of such athletes.

WWF also criticised the use of artificial snow, saying it weighs as much as five times more than real snow, damaging the ground and requiring millions of cubic metres of water.

But the group also listed seven positive results, including the construction of buildings in Turin that will be used after the Games, clean-fuel public transport and recycling of materials in the Olympic villages.

The organisers say the Turin Games will be the most environmentally friendly Olympics ever and, by offsetting all carbon emissions produced during the 17 days, will have no net impact on climate change.

"Even Winter Olympics have to have some environmental impact," Saini said. "But in this case it is not overly dramatic."