BMW Williams were unable to be competitive during the 2005 season

The German giants split from Williams and bought out Sauber, but both were eclipsed by Renault, who won the 2005 drivers' and constructors' titles.

Motorsport director Mario Theissen said: "Obviously we are not satisfied with fifth place in the constructors'."

Sauber's 300-strong workforce will be bolstered by 300 current BMW staff joining and another 100 to be added.

There are also plans to further utilise Sauber's wind tunnel system as attempts continue to bridge the gap at the top.

"Reinforcements for the aerodynamics department in Hinwil are the top priority," Theissen confirmed.

"We are looking to use the outstanding wind tunnel as frequently as possible, as soon as possible."

Referring to the end of the partnership with Williams, Theissen added: "Over six years, both sides have learned a lot and benefited a great deal, both are stronger than at the start of our joint venture, but extending the partnership would not have made us any faster."