Alcoa (NYSE: AA) is the worl’s third largest producer of aluminum, behind Rio Tinto and Rusal. Alcoa leads the world in alumina production and capacity. From its operational headquarters in Pittsburgh, Pennsylvania, Alcoa conducts operations in 44 countries. In May 2007 Alcoa made a hostile $27 billion bid for Alcan, a former subsidiary, aiming to unite the two companies and form the worldest largest aluminum producer. The takeover bid was withdrawn after Alcan announced a friendly takeover by Rio Tinto in July 2007.