Aug 2 (Reuters) - Electric vehicle sales at China"s Li Auto and Xpeng Inc more than tripled in July from a year ago, while they doubled at Nio Inc (NIO.N), helped by robust demand for new energy automobiles in the world"s biggest auto market. The rise in July deliveries comes at a time when electric car makers have been expanding manufacturing capacity in China, encouraged by the country"s policy of promoting greener vehicles. U.S.-listed shares of Xpeng surged as much as 8.9% to a near two-week high of $44.12, Li Auto rose as much as 6.1% to a one-month high of $35.44, while Nio gained as much as 4.7% at $46.78. Nio, Li Auto and Xpeng compete with U.S. electric car maker Tesla (TSLA.O), which dominates the EV market in China. Nio, the maker of the ES8 and ES6 electric sport-utility vehicles, said it delivered a total of 7,931 vehicles in July, up 124.5% from a year earlier. Deliveries had more than quadrupled in July 2020. Xpeng, which makes the P7 sedan and G3 sport-utility vehicles, said its July deliveries jumped 228% to 8,040 vehicles. Li Auto, the producer of Li ONE SUVs, said it delivered 8,589 Li ONEs last month, an increase of about 251%. The strong sales numbers for the EV makers come as a global recovery in auto sales is being threatened by chip shortage that has forced automakers around the world to adjust assembly lines, cut productions and shutter factories.