BMW set to extend Kubica's deal

Kubica's strong start to the season, which has left him fourth overall in the drivers' championship, has made him an obvious target for front-running teams well aware that he is only officially confirmed until the end of this year.

However, sources close to Kubica have told autosport.com that there is an option in his contract that gives BMW Sauber the automatic right to sign him up for another season.

The option, which is believed to expire in September, essentially gives the team until the summer to decide whether or not they want to keep Kubica on board.

With his current form, the matter looks a formality - although in theory BMW Sauber could choose to sell the Pole's contract on to another team.

Last year, Kubica was informed immediately after his Canadian Grand Prix crash that he would be retained for 2008, and BMW motorsport director Mario Theissen has already suggested the team will finalise their drivers in the next few months.

When asked by autosport.com if he was worried that Kubica's speed would increase the likelihood of a rival team trying to poach the Pole, Theissen said: "No. When we took him, we expected him to be strong. We'll announce next year's drivers in the summer."

Theissen has said that he believes the improved F1.08 has keen key to allowing Kubica to show the raw speed that was so evident in 2006 but missing for parts of last year.

"Yes. I would say he's back on track," explained Theissen. "What we're seeing now is quite similar to what we saw in 2006.

"He had a very tough year last year and it was more difficult for him than for other drivers to adapt to the standard spec tyre and he had quite a few technical problems and then quite a big shunt. So it was a learning year and now he's back on track."