The announcement brings an end to months of speculation over the future of German Heidfeld, whose place at the team was rumoured to be under threat from Renault's two-time world champion Fernando Alonso.

Kubica's future has been equally uncertain, with BMW reportedly keen for the Polish star to sign a three-year deal despite the driver's apparent wish to keep his options open for 2010.

BMW also confirmed Austrian test and reserve driver Christian Klien will continue with the team into 2009.

"We see Nick and Robert as a strong driver pairing and Christian as an experienced test driver," said BMW Motorsport Director Mario Theissen.

"We are in no doubt that we will again achieve our ambitious aims with them in the team's fourth year."

Kubica claimed the team's first-ever win at the Canadian Grand Prix in June.

The 23-year-old, who has visited the podium six times in 2008, sits third in the drivers' standings with three races to go, 20 points behind championship leader Lewis Hamilton.

Heidfeld, who has finished second at four grands prix this season, is fifth in the championship, eight points behind his team-mate.