General Motors Co. (GM) trucks are being investigated by U.S. auto-safety regulators because faulty fuel- tank readings may lead drivers to think there’s more gasoline in the vehicles than there really is.

The U.S. National Highway Traffic Safety Administration said today on its website it is probing about 865,000 Chevrolet, GMC, Buick and Saab vehicles. The agency said it received 668 complaints, including 610 that didn’t result in stalling, and one report of a crash attributed to the defect.

“GM is cooperating with the NHTSA in the investigation,” Alan Adler, a spokesman for GM, which no longer owns the Saab brand, said in an e-mail.

The investigation applies to model years 2005 to 2007 of Chevrolet Trailblazers, GMC Envoys, Buick Rainiers and Saab 9- 7Xs. No accidents or injuries have been attributed to the defect, which can lead to stalling because of lack of fuel, according to NHTSA.

GM rose 31 cents to $32.22 at 10:56 a.m. in New York Stock Exchange composite trading.