Martin Whitmarsh urges Williams to sign Kimi Raikkonen

Raikkonen raced for McLaren from 2002-2006, winning nine grands prix, and Whitmarsh came close to re-signing him for 2010 before opting for Jenson Button.

Williams has held talks with Raikkonen and is considering taking him on in a move believed to be contingent on landing major backing from Qatar. But despite question marks over how motivated the Finn is to return to F1 after two seasons out, Whitmarsh has no doubts about his ability.

"Try and sign him," said Whitmarsh when asked to give advice to Williams on Raikkonen. "We all know he is quick and I think people underestimate how intelligent he can be.

"I hope that he is hungry. I am sure that he hasn't lost the capability to thrill us, so I think it would be fantastic for Formula 1. I wouldn't ordinarily presume to advise Sir Frank who he should sign, but I think it would be exciting if he did."

Williams would not comment on his interest in Raikkonen, saying that "I cannot make any comment about supposition", but he did confirm that a slot could be available in the team's 2012 driver line-up.

Venezuelan Pastor Maldonado, who has impressed during his rookie season and comes with the blessing of major sponsor PDVSA is set to stay on, but team-mate Rubens Barrichello's future is uncertain.

"[It's] not clear exactly who will be in both cars," said Williams "I am sure Pastor will be in one car. Rubens maybe.

"We haven't really made up our minds what we want to do before we talk to Rubens."

Williams also hinted that reserve driver Valterri Bottas, who has been on the team's books since the start of last season, could also be in the frame.

The GP3 champion will drive for Williams during two days at next week's young driver test and is known to be an outsider for the drive if he impresses the team.

"It depends how quick he is," said Williams. "I don't know enough about him.

"He looks very good, but beyond saying that, I don't know him. We have to keep testing him, I guess."