Traders anticipate a sharply lower start for U.S. soybean futures Thursday, fueled by a broad based commodity selloff.

Concerns about the state of the U.S. and global economies are driving widespread risk reduction by world investors. Steep losses in crude oil futures, tumbling world equity markets and a sharply higher U.S. dollar are expected to spill over into grain and oilseed markets.

"U.S. and world investors are shedding risk with their economic worries growing," according to an AgResource Company market note.

CBOT soybeans are called to open down 25 cents to 30 cents.

In overnight trading, Chicago Board of Trade November soybean futures were down 26 1/2 cents or 2% at $12.94 a bushel.

The influence of external financial markets will have strong impact on prices amid renewed worries of the world's economic outlook.

Global financial markets tumbled overnight following Wednesday's statement from U.S. Federal Reserve that there were significant downside risks to their economic forecast. The Federal Reserve also expressed concern that weak economic growth could deteriorate further.

Money managers are cautious of risk exposure in the face of a tenuous global economy, with seasonal pressure from the expected influx of supplies from the fall harvest adding the lower price theme.

Industry analysts anticipate traders will remain hesitant to add risk, as they anxiously awaiting actual yield results from the autumn harvest.

Nevertheless, futures aren't expected withstand the pressure from external financial markets despite longer range fundamentally tight supply forecasts.

"Until harvest and external financial market price pressure has been relieved, the ability for the grain markets to sustain rallies seems small indeed," Dennis Gartman, editor of the Gartman Letter wrote in a morning market note.

However, traders are encouraged that a 8.4% drop in soybean prices in the last eight trading days is generating new export demand.

U.S. Department of Agriculture announced Thursday private exporters reported the sale of 180,000 metric tons of soybeans for delivery to China during the 2011/2012 marketing year.

Meanwhile, U.S. soybean sales totaled 404,400 metric tons in the week ended Sept. 15, the USDA reported in its weekly sales report. Sales increases were noted to China at 176,300 tons. Analysts anticipated sales in a range of 200,000 to 800,000 tons.