By David B. Wilkerson
CHICAGO (MarketWatch) -- General Motors Co. GM -0.70% said Tuesday that U.S. sales rose 10% in August, as the Buick, Chevrolet and Cadillac showed solid improvement. Total sales were 240,520 vehicles, up from 218,479 in August 2011. Buick sales rose 12%, while Chevrolet and Cadillac sales each rose 11%.
