GM, which filed for bankruptcy protection on June 1, said that it delivered 176,571 vehicles in June, compared with 265,937 a year earlier, roughly in line with analysts' expectations given the turmoil of its restructuring.
Still the top-selling automaker in the United States, GM's sales declines were led by brands it expects to carve away as part of its restructuring.
Sales at GM's Saturn brand fell 60.2 percent, Saab sales were down 58.4 percent and Hummer brand sales were down 48 percent from a year earlier. GM hopes to sell those brands.
However, sales at the Pontiac brand were down 16.4 percent. GM plans to wind-down the Pontiac brand gradually and focus on its Chevrolet, GMC, Buick and Cadillac brands.
The automaker also said in a call with analysts that it saw some softening in demand toward the end of June and said there was still evidence of some headwinds in the U.S. economy.
GM said it produced 394,000 vehicles in the second quarter in North America, down about 53 percent from a year earlier.
GM declined to disclose a third-quarter production plan.