The 24-year-old began his grand prix career with the British outfit in 2006 but is tipped to switch to McLaren-Mercedes for next year.

Williams has recognised the likelihood of losing Nico Rosberg to a rival formula one team at the end of the season.

The 24-year-old began his grand prix career with the British outfit in 2006 but is tipped to switch to McLaren-Mercedes for next year.

"We would gladly keep Nico, but he will probably take another option," Williams co-owner and engineering chief Patrick Head is quoted as saying by Germany's Auto Bild Motorsport.

German-born Rosberg, the son of 1982 world champion Keke Rosberg of Finland, has scored all of the Grove based team's 29.5 points so far this season.