LES SABLES D'OLONNE (France) - THE Australian Navy has sent a frigate to rescue Yann Elies after the French sailor broke his leg while competing in the Vendee Globe round-the-world yacht race.

The HMAS Arunta left Fremantle on Australia's west coast early on Friday and is expected to reach the yacht Generali on Sunday, although rough weather and bad seas could slow the expected 1,300km trip.

Elies requested evacuation after fracturing his leg while working on deck.

The Australian ship responded to calls from Australian Search and Rescue, which was contacted by race organisers late on Thursday, less than seven hours before Arunta set sail. The ship is carrying a doctor and has a helicopter to help in rescue efforts.

'Elies was working at the bow, leaning on the pulpit, as he was preparing a sail, when his 60-foot boat, Generali, came to a sudden halt slamming into a wave,' a statement on the race website said.

'The sailor felt a sudden acute pain. He collapsed on the foredeck and had to crawl back inside his boat to contact his team.' The race doctor, Jean-Yves Chauve, said Elies had a suspected broken femur.

Elies was resting in his bunk at the chart table, but with the violent motion of the boat, has so far been unable to reach his medicine kit for painkillers.

'Not surprisingly he can't find the nerve to move a few metres across the cabin sole (floor), which is obviously being jolted about every which way by the sea state. However, he desperately needs to get to the medication both physically and mentally now as he's in so much pain,' race organisers said.

Compatriot Marc Guillemot on Safran, and Briton Samantha Davies on Roxy, have changed course to 'offer the injured skipper psychological support.' Guillemot was expected to reach Elias soon, while Davies was still some 600km and 40 hours away.

'I am ready for anything in my bid to assist Yann,' Davies said. 'He's my No. 1 objective now. I will stay there as long as it takes the emergency services to arrive and ensure he is not on his own.'

The Vendee, a single-handed race for men and women without any stopovers, set off from Les Sables d'Olonne on Nov 9.

Thirty Open 60 race boats - high-tech carbon-fiber yachts built to be fast yet tough - began the race, but more than a third of the fleet has been forced to retire with less than half the race distance covered.

The Vendee takes the fleet around the three great capes - the Cape of Good Hope, Cape Leeuwin and Cape Horn - marking the southern tips of Africa, Australia and America. -- AP