Hong Kong's Hang Seng index ended down 2.2 per cent 12,475.87 - its lowest close since August 11. Tokyo's Nikkei average ended off 1.9 percent, below the key 18,000-point level, at 17,754.49, troubled by a firming Yen.

At 1035 GMT, the dollar was quoted at 107.56/59 Yen,rising sharply after the Bank of Japan's board decided to maintain its basic easy monetary policy but to start outright buying of treasury and financial bills. The central bank announced its decision hours after the Tokyo market closed.