Sutil joins Williams as reserve driver

The German was left without a race seat at the end of last year after having driven for the struggling Sauber team alongside Esteban Gutierrez.

Williams did not have a reserve driver, something that was highlighted earlier this month when Valtteri Bottas had to sit out the Australian Grand Prix due to injury.

"I'm delighted to have Adrian join our stable of drivers for the 2015 season," said Frank Williams. "Adrian brings extensive racing experience, having competed 128 Formula One races during his career.

"Having most recently raced during the 2014 season also gives him excellent knowledge of the current generation of race car and new Hybrid power units, which is invaluable for anyone needing to step into the cockpit in 2015.

"The fight for a top Constructors' Championship position will be intense this season, therefore we have selected a driver with recent race experience and are confident that if the need arose, he would be a solid pair of hands to race the FW37 and assist our 2015 campaign."

Sutil, who made his Formula One debut in 2007, will work with Williams' simulator to get accustomed to the FW37 should he need to drive it.

"I'm very proud to be a part of such a famous and great F1 team," said Sutil. "To work for Sir Frank Williams and his team means a lot to me. I would like to thank everyone at Williams for their belief in my qualities and the opportunity to work with such a successful and competitive outfit."