Japanese automakers posted more than 20 percent sales gains in August in the United States, helping expand the overall market by 17 percent from a year earlier to 1.5 million vehicles, the highest for a single month since May 2007, Autodata Corp. said.

Buyers were apparently encouraged by a moderate recovery in the economy and low interest rates that made it easy to sign up for loans, underscoring the continuing expansion of the U.S. car market.

The August sum translates into an annualized 16.09 million units after seasonal adjustments, the highest since October 2007.

Toyota Motor Corp.'s sales climbed 22.8 percent to 231,537 units, making it the second-biggest seller in the country after General Motors Co. for the second month in a row, thanks to solid sales of the key Camry model and Prius hybrid.

Honda Motor Co. registered a 26.7 percent rise with 166,432 units on the back of brisk demand for the Civic car and the CR-V sports utility vehicle.

Nissan Motor Co. marked a 22.3 percent climb to 120,498 units, owing in part to steady sales of its mainstream Altima.

Honda was fourth in monthly sales and Nissan sixth. Both recorded their best August sales ever.

Top seller GM scored a 14.7 percent increase, selling 275,847 units. Third-ranked Ford Motor Co. boosted sales by 12 percent to 220,404 units. Chrysler LLC, which placed fifth, sold 161,362 units, up 11.8 percent.

Three other Japanese players posted brisk double-digit gains. Fuji Heavy Industries Ltd., known for the Subaru brand, marketed 41,061 units, up 45.1 percent. Mazda Motor Corp.'s sales grew 26.4 percent to 28,106 units. Mitsubishi Motors Corp. saw its sales advance 24.3 percent to 5,281 units.