Nikkei: 9,716.65 (-147.61) Hang Seng: 23,073.76 (-218.04) Shanghai Comp: 2,845.11 (-38.31)ASIAN STOCKS fell, with the key regional index set for its biggest slide since markets crashed in the wake of Japan's record earthquake in March, as commodity prices tumbled amid concern that China will further tighten monetary policy.

BHP Billiton, the world’s largest mining company, dropped 2.6 per cent in Sydney after oil and metal prices sank yesterday in New York.

Jiangxi Copper, China’s No 1 producer of the metal, declined 2.4 per cent in Hong Kong.

Korea Zinc slid 5.7 per cent in Seoul, while Mitsubishi, Japan’s biggest commodities trader, fell 2 per cent. Olympus, an optical-equipment maker, lost 5.6 per cent in Tokyo after reporting an 85 per cent slump in profit.

Japan’s Nikkei 225 Stock Average fell 1.5 per cent and Hong Kong’s Hang Seng Index retreated 1.1 per cent.

BHP Billiton, also Australia’s No 1 oil producer, lost 2.6 per cent to A$44.13 in Sydney, while Rio Tinto, the world’s No 2 mining company by sales, retreated 2 per cent to A$79.79. Jiangxi Copper slumped 2.4 per cent to HK$24.05 in Hong Kong. Mitsubishi declined 2 per cent to 2,112 yen in Tokyo. –(Bloomberg)