NEW YORK (CNN/Money) - General Motors Corp. continued to outdistance its competitors as it posted a gain in U.S. sales in June while Ford Motor Co. and Chrysler Group both reported drops from a year earlier.

GM, the world's largest automaker, sold 455,628 cars and light trucks, a 4.6 percent rise when adjusted for one less selling day in the latest month. Car sales rose 2.5 percent to 215,741 on that basis and light truck sales, including sport/utility vehicles, minivans and pickups, gained 6.5 percent to 239,887.

Paul Ballew, GM's executive director for market and industry analysis, said that the company expects to see continued improvement in the economy and its own sales position in the second half of the year. He said that all the company's brands other than Oldsmobile, which it is phasing out, are gaining market share.

Dearborn, Mich.-based Ford, the world's No. 2 automaker, said car sales fell to 128,649, a 10.6 percent decline from a year earlier when one fewer selling day in the current period is taken into account. Light trucks also dropped 10.6 percent to 208,651.

The results leave Ford's sales for the first six months off 10.7 percent from a year earlier, with car sales off 14.2 percent and truck sales down 8.5 percent. The company saw its fleet sales to businesses fall by 5 percent, and its retail shares to consumers off 12 percent, with both those declines spread pretty evenly between cars and trucks.

Chrysler, the North American unit of DaimlerChrysler AG, the world's No. 3 automaker, said U.S. sales fell to 202,822 vehicles, a 4 percent decline when accounting for the selling days. Light truck sales were basically unchanged, while car sales fell 12 percent.

Shares of GM (GM: up $0.16 to $50.98, Research, Estimates) and Ford (F: up $0.30 to $15.82, Research, Estimates) gained in afternoon trading following the sales reports, while shares of DaimlerChrysler (DCX: down $1.22 to $45.80, Research, Estimates) were off in New York trading.