Christian Klien believes he has a 'very realistic chance' of returning to an F1 race seat for the 2010 season.

The Austrian driver hasn't raced in F1 since leaving Red Bull back in 2006 having since taken up test driver duties with Honda and BMW Sauber.

Klien had hoped to move up to race seat with BMW before the German manufacturer announced it was to quit the sport, but he admitted that uncertainty over whether or not the team will be on the grid in its new guise meant he was unsure if a deal would be possible.

"Had BMW Sauber signed in for 2010 I would most likely have been guaranteed a race seat," he said. "The successor has no official entry for 2010 yet. But everyone in Hinwil is working flat out on next year's race car.

"Having said that it seems clear that all decisions such as sponsorship deals and driver line-up cannot be announced before that matter is resolved. I am positive that the traditional Sauber team from Hinwil will be on the grid in Bahrain in 2010."

While the Qadbak-owned outfit could be one possibility for Klien if it can secure a place on the grid, the 26-year-old revealed that he had spoken to other new teams about a drive and said he was confident that he will return to the grid next year.

"I was approached by several teams concerning a race drive during the season," he said. "The new teams are interested in drivers with F1 experience to speed up the development of their car. In the meantime I have had a close look at everyone's progress and I have also checked with their engine partner Cosworth. The first season is going to be very tough for the new teams, but some definitely have the potential to go far in F1.

"This winter the situation is unique: F1 is in the process of being rebuilt. Existing teams are closing their doors and new ones join the field. For the first time, there is practically no testing between November and January. The regular drivers will not be in the car before February. As a consequence there is much less pressure for the teams on the drivers' side. For 2010 I still see a very realistic chance to be racing in F1."

Klien could yet continue in sportscar competition with Peugeot next season although a decision won't be taken until his F1 future is decided.