Auto sales in China, the world's biggest car market, rebounded in August as subsidies for energy-efficient vehicles and a stronger currency spurred demand, while sales in the US faltered. Sales rose 55.7 percent over a year earlier to 1.21 million vehicles, up from 1 million vehicles the month before, the Cabinet's China Automotive Technology and Research Center said Wednesday. The increase compared with 17 percent year-on-year growth in July and 19.4 percent in June. The upbeat news from China contrasted sharply with figures on US auto sales, which had their worst August since 1983. General Motors, Toyota, Honda and Ford all reported declines from the month before and from a year earlier. Initial data showed US sales in August at about 997,000, down 5 percent from July, according to AutoData Corp. In China, though, sales of energy saving vehicles rose 32 percent to 129,600, the China Automotive Technology and Research Center said in a report posted on its website. Demand was also relatively strong for imported vehicles, as Japanese and European automakers increasingly focus on serving the market for smaller, affordable cars, said its chairman, Zhao Hang, without giving specific figures. A recent rise in the value of China's currency has also stimulated sales of imported cars. “That makes things cheaper,” he said. In June, China loosened controls that had kept its currency trading at about 6.83 yuan per US dollar for over a year. Late Wednesday, the yuan was trading at 6.8112 to the dollar. The rebound in sales is good news for global automakers looking to China to drive sales amid weak global demand. Sales this year are forecast to grow by no more than 20 percent, well off 2009's stunning 45 percent rise. General Motors Co. reported that its sales in China rose 19.2 percent in August from the year before to 181,625 vehicles, with sales for the first eight months of 2010 at 1.5 million units.