The Detroit News reports that Mark LaNeve, head of sales and marketing for North America, sent dealers an e-mail telling them the company is "investing more heavily than ever on new products and marketing programs."

GM is already closing out its Oldsmobile brand. That leaves the company with eight nameplates in North America, Buick, Pontiac, Chevrolet, Cadillac, GMC, Hummer, Saab and Saturn. Sales of Buick and Pontiac have been dropping for years.

On Wednesday, Vice Chairman Bob Lutz said that "damaged brands" that fail to meet sales targets could be abandoned. That left dealers worried, the News said.

"They got dealers scared to death," Phil Shostack, sales manager at a Buick-Pontiac dealership in Royal Oak. He said that his dealership is in the middle of an expansion.

LaNeve in his e-mail said the company has no plans to abandon any nameplates.

GM, once the world's dominant automaker, has seen its share of the American market drop from 64 percent to 27 percent in the past 25 years.