Sauber are aiming to challenge for the 2009 championship

BMW, who took over Sauber at the end of 2005, had two podium finishes in 2006.

"Our aim is to make it onto the podium in 2007 on our own merit. Victories are not yet a realistic prospect.

"We are aiming for that in 2008. In 2009 we want to be in contention for the world championship," said team boss Mario Theissen at the new car's launch.

The team ended up in fifth with 36 points last season, an improvement on Sauber's eighth place finish in 2005, although they were still 50 points behind fourth-placed Honda.

And Theissen believes the pressure is on the team to continue their improvement this year.

"In 2006 we exceeded our own targets and now expectations are rising faster than the team can develop," he said. "That's the punishment for excelling yourself.

One can't expect too much because the higher you go, the more rarified the atmosphere BMW Sauber driver Nick Heidfeld

"If the leading teams show any sign of weakness, we want to be ready to breach the gap."

The team's new F1.07 has a completely redesigned front wing, a revised cooling system, a slimmed down rear end and a seamless-shift gearbox.

"It's really the first BMW Sauber," said Theissen. "That's a very special day for us."

German driver Nick Heidfeld, who will be partnered by Poland's Robert Kubica, says it will be difficult to match last year's encouraging displays.

"After our good maiden season we now have to continue along our set path," he said.

"But one can't expect too much because the higher you go, the more rarified the atmosphere."

Kubica starts his first full season after replacing Jacques Villeneuve in August.

"I learned a lot in 2006," said Kubica, who came third at Monza in only his third race.

"And I want to put it into practice in 2007 and learn more.

"To stand on the podium for the first time after a Formula One race was an incredible experience. I want more of it."