Asian stocks slumped, sending the region's benchmark index to the lowest level in four years, after commodity prices tumbled on concern a global economic slowdown is reducing demand for raw materials.
Posco retreated 7.8 percent after global steel production dropped last month. BHP Billiton Ltd. and Rio Tinto Group plunged more than 8 percent after European regulators said a takeover of Rio by BHP may break antitrust rules, people close to the case said. Australia & New Zealand Banking Group Ltd. lost 4.8 percent after profit fell by a third.