Jaguar have freed Australian Mark Webber to test for Williams after the season-ending Formula One race in Brazil this month.

"In order to continue to support Mark Webber in his career, he will be released from his testing duties with Jaguar Racing post the final race in Brazil in order to start his 2004 winter test programme with his 2005 team," Jaguar said at the Japanese Grand Prix.

Jaguar are facing an uncertain future after owners Ford announced they were pulling out of Formula One at the end of the season and selling the team and engine maker Cosworth.

Webber has signed a deal taking him to former champions Williams but would normally have remained under contract to Jaguar until the end of the year.

Jaguar said Webber would test for BMW-powered Williams in plain overalls when testing starts up again in December and will remain under contract to his old team for sponsorship and marketing commitments until January.