DETROIT -- Some Chevrolet dealers are turning down Volts that General Motors wants to ship to them, a potential stumbling block as GM looks to accelerate sales of the plug-in hybrid.

For example, consider the New York City market. Last month, GM allocated 104 Volts to 14 dealerships in the area, according to a person familiar with the matter.

Dealers took just 31 of them, the lowest take rate for any Chevy model in that market last month. That group of dealers ordered more than 90 percent of the other vehicles they were eligible to take, the source said.

In Clovis, Calif., meanwhile, Brett Hedrick, dealer principal at Hedrick's Chevrolet, sold 10 Volts last year. But in December and January he turned down all six Volts allocated to him under GM's "turn-and-earn" system, which distributes vehicles based on past sales volumes and inventory levels.