 At the end of the 2005 season, the team's majority shareholding previously owned by Credit Suisse was bought by BMW, with Peter Sauber retaining a 20% stake, and was renamed BMW Sauber.BMW sold its part back to Peter Sauber after the end of the 2009 season, but the team formally used the name 'BMW Sauber' until the end of the 2010 season.For the season the team re-signed Nick Heidfeld from Williams to be their lead driver (Heidfeld drove for Sauber in 2001-2003), while 1997 World Champion Jacques Villeneuve had his existing Sauber contract confirmed.