By Saikat Chatterjee

HONG KONG (Reuters) -- Asian stocks fell on Wednesday as global growth worries stung Wall Street, sending investors scampering to the relative safety of the yen and government debt.

MSCI's broadest index of Asia-Pacific shares outside Japan slipped 0.3 percent, withAustralia down 1.3 percent and South Korea falling 0.8 percent. Japanese markets are shut through Wednesday.

Fresh cracks in the commodities complex, amplified by drops in copper, raised concerns that a China-led slowdown may pose significant headwinds for riskier assets, particularly equities.

Downside risks to global growth have increased and the weak economic outlook will make achieving world development goals more difficult than in the past, the head of the International Monetary Fund said on Tuesday.

Attention will be squarely focused on the China August flash factory PMI survey due to be released at 0145 GMT.

Economists polled by Reuters expect the flash PMI to edge up to 47.5 in September from the final 47.3 in August, but that would still leave it near 6-1/2-year lows and point to a seventh straight monthly contraction in activity.

On Tuesday, the Asian Development Bank lowered its growth forecast for China to 6.8 percent for 2015.

Overnight on Wall Street, the Dow Jones industrial average fell 1.09 percent, the S&P 500lost 1.23 percent, and the Nasdaq Composite fell 1.5 percent to 4,756.72.

Losses in equities prompted investors to plough funds into fixed income assets. The benchmark two-year U.S. Treasury yield fell to 0.67 percent, nearing a two-week low.

In currencies, the U.S. dollar consolidated most of its overnight gains in early Asian trade. It held firm at 96.439 against a basket of six currencies, after earlier rising 1 percent. The Japanese yen held firm against the dollar at 120.24 as investors shied away from adding risky bets.

U.S. crude futures rose 0.4 percent to $46.51 per barrel, while Brent futures were 0.2 percent firmer at $49.18.

(Editing by Shri Navaratnam)