GM said on Tuesday it will “review” the future of its Saab and Saturn brands, as it struggles to survive and restructures its business to focus on core brands.

The automaker said it will focus its product development and marketing efforts in the United States on four core brands –Chevrolet, Cadillac, Buick and GMC.

GM said it will “immediately undertake a global strategic review of the Saab brand,” in a statement outlining a restructuring plan it presented to Congress in hopes of securing some 18 billion dollars in government-backed loans.

“As part of the plan, the company also will accelerate discussions with the Saturn retailers, consistent with their unique relationship, to explore alternatives for the Saturn brand,” GM said.

Pontiac will become a “specialty brand with reduced product offerings,” GM said, adding it has already begun exploring the sale of its hulking Hummer brand.

GM said it will cut the number of vehicle types it offers in the United States to 40 in 2012 from 51 in 2000.

It will also slash its dealer network to 4,700 in 2012 from 8,138 in 2000.

GM currently sells 48 different vehicles at 6,450 dealers in the United States.