Aluminum stockpiles have risen to the highest level in two years as supply growth exceeds demand in China’s main trading regions, Bloomberg reported. Wen Junxiang, head of the research department at Guangzhou KT Commodity Information & Consulting, said that reserves in Shanghai, Wuxi, Hangzhou and Guangdong province had grown to about 940,000 metric tons as of October 22. Zhang Chenguang, an analyst at data provider SMM Information & Technology, said stockpiles more than doubled to about 1 million tons. New capacity in the West has helped push global aluminum output to its highest level ever, even as falling manufacturing in China has lessened demand. Alcoa (AA.NYSE), the largest US producer, cut its forecast for global demand due to China’s economic slowdown, while the price of aluminum in London has dropped 13%.