SEOUL, South Korea (AP) - Apple's grip on China's tablet market has loosened as Asian tech companies increase sales with cheaper Android tablet computers. Dickie Chang, senior market analyst at IDC, said Thursday that Apple supplied 28 percent of tablet computers in China during the April-June quarter, down from 49 percent dominance a year earlier. The iPad maker was still the biggest tablet supplier in China, its key growth engine, but its momentum has slowed. Chang said South Korea's Samsung Electronics, China's Lenovo, and Taiwan's ASUS and Acer benefited with a surge in their market share. He said Samsung claimed 11 percent tablet market share, up from 6 percent. China is a key market for consumer technology companies as growth in sales of smartphones and tablets slows in developed countries.