By Alan Baldwin

A much-improved BMW Sauber could play a big role in this year's Formula One championship, according to Gerhard Berger.

The Austrian, a former race winner for Ferrari and McLaren who also served as BMW's motorsport director and now co-owns the Ferrari-powered Toro Rosso team, said the main battle would be between McLaren and Ferrari.

"I believe we are going to see a fight for the championship between (McLaren's double world champion Fernando) Alonso and (Ferrari's Kimi) Raikkonen," Berger told Reuters in a telephone interview on Tuesday.

"But I see BMW in certain races playing a very strong role. We can see from the tests they have built a good car," added Berger, who won in Mexico in 1986 with a BMW-powered Benetton.

BMW, who bought Swiss-based Sauber at the end of 2005, finished fifth last year with Polish rookie Robert Kubica making a big impression after replacing former champion Jacques Villeneuve in August.

Berger predicted that Renault, winners of both championships in 2005 and 2006 before Alonso left to join McLaren, would also be strong.

The Anglo-French team have experienced Italian Giancarlo Fisichella staying on to partner Finnish rookie Heikki Kovalainen, previously the test driver.

TALENTED DRIVER

"Kovalainen is obviously a very talented driver but I doubt he will play a role in the championship," said Berger, who ended his grand prix career in a Renault-powered Benetton in 1997.

"But I do believe he will have some good races and is sometimes going to be in a position maybe to win."

Toro Rosso, the former Minardi team bought by Red Bull at the end of 2005, scored only one point last season.

Their new car is the brainchild of former Williams and McLaren designer Adrian Newey and similar to Red Bull's.

Berger did not discount the possibility of Toro Rosso battling with their Renault-powered sister team.

"We are still a very small team, it's going to be very difficult for us to compete with the big teams," he said.

"The next teams ahead of us are Williams, Toyota, Red Bull, all huge operations with a lot of experience.

"It would be dreaming too much to think we could be able to beat them but our definite goal is to come closer and maybe there will be some races where we can compete with them."