Mark Webber to leave F1 at the end of season; to race at Le Mans from 2014

Mark Webber on Thursday confirmed what many close observers suspected when he announced that he will be leaving Red Bull and Formula One at the end of this season to switch to sportscar racing with Porsche's LMP1 team.

The Australian, who will be 37 in August, has been expected to make a move ever since his Red Bull team-mate, triple world champion German Sebastian Vettel, disobeyed team orders to "steal" victory from him at the Malaysian Grand Prix in March.

Webber made the announcement by posting a Porsche statement on his website markwebber.com.

"It's an honour for me to join Porsche at its return to the top category in Le Mans and in the sports car World Endurance Championship and be part of the team," he said.

"Porsche has written racing history as a manufacturer and stands for outstanding technology and performance at the highest level."

Finland's Kimi Raikkonen, the 2007 world champion who returned to F1 with Lotus last year after a spell in rallying, is expected to be a leading contender to replace Webber at the Red Bull team, based in Milton Keynes, south central England.

At 33, he retains the pace and has the race craft to be a good replacement for Webber even if Vettel could be reluctant to adopt his allegedly carousing lifestyle.

Another Australian Dan Ricciardo, currently with Toro Rosso, could also be a contender if he rises to the challenge in the second half of this season and Raikkonen rejects the move.

Webber has previous experience racing in sportscars with Mercedes in 1998/99 before he went back to single-seaters in Formula 3000 en route to joining fellow-Australian Paul Stoddart's Minardi team in F1 in 2002.

He made his debut at Melbourne in the Australian Grand Prix and famously finished fifth, a result that incited such crowd reaction that Webber and Stoddart were required to perform an unofficial podium celebration of their own.

After spells at Jaguar and Williams, he joined Red Bull from 2008 and became the solid, reliable and dogged racer who built the foundations for Vettel's rise to fame after he switched to join the team from their junior sister outfit Toro Rosso.

He became a race-winner and title contender with the team but was unable to match team-mate Vettel's success and has had to endure a turbulent relationship with the pragmatic 25-year-old German in a team in which, despite protestations by the management, he has always been seen as the second driver.

After winning the British Grand Prix in 2010, having been given second use of new parts for his car, he responded to team chief Christian Horner's effusive praise over the team radio by saying: "Not bad for a second driver."

His announcement -- and his feisty relations with Vettel -- is unlikely to see the young German given many favours between now and the season's end.

Born in Queanbeyan, New South Wales, Webber has started 203 Grands Prix, winning nine. He has secured 11 pole positions and recorded 15 fastest laps.

Webber is certain to be at his determined and dogged best this weekend as he bids to complete a hat-trick of Silverstone victories in five years.

He has finished on the podium in all of the last four races, winning twice, in 2010 and 2012. He took pole in 2011.

Webber has used the soubriquet "Aussie grit" for his Twitter identity and manifested the same attitude in his life, proving it in the manner in which he recovered from serious injuries following a cycling accident when he was hit by a car in Tasmania in November 2008.

He broke his leg but recovered sufficiently to race with pins in the limb at the season-opening Australian Grand Prix in Melbourne the following March.

"I'm very much looking forward to this new challenge after my time in Formula One. Porsche will undoubtedly set itself very high goals. I can hardly wait to pilot one of the fastest sports cars in the world," he added.

Webber's multi-year contract with Porsche will see him return to the Le Mans 24 Hours race and World Endurance Championship.

In 1998, he finished runner-up in the GT Championship.