The Swiss-based team ended the season in fifth place, a point ahead of big-budget Toyota, while their former partners Williams were eighth.

Sauber finished last year in eighth place.

"In our first year we made it onto the podium twice and that wasn't necessarily to be expected," said Theissen in a team question and answer session.

"But far more important was the way we consistently improved our performance throughout the season, and that shows we are on the right track."

Germany's Nick Heidfeld and Poland's Robert Kubica, who replaced Canadian Jacques Villeneuve in August, have been confirmed as the team's 2007 line-up with German teenager Sebastian Vettel the reserve driver.