Glencore International AG., the world's largest commodities trader, will buy a stake in China's second-biggest aluminum producer, state-owned Qingtongxia Aluminium Group, to tap rising demand for the metal used to make beverage cans and automobiles, Bloomberg reported. Glencore joins Alcan Inc., the world's second-largest aluminum producer, in expanding in China, where demand is expected to double in 15 years. This year's declines in the price of alumina, used to make aluminum, have increased the attraction of smelters for overseas companies, quoted Wang Feihong an analyst at Beijing Antaike Information Development Co as saying. Qingtongxia Aluminium, located in western Ningxia Autonomous region, was founded in 1964 and is owned by the local government. It has hydropower and coal-fired power stations. The company set up the country's first aluminum joint venture with Alcan two years ago, including a 150,000-ton smelter and a coal-fired power plant.