US soyabean futures fell on Wednesday for a fourth straight session on long liquidation and profit-taking ahead of a key US government crop report and jitters over next week's presidential election, analysts said. Corn also declined, with the December contract nearing a three-week low. Wheat firmed on short-covering as investors headed for the sidelines.
As of 12:49 pm CDT (1749 GMT), Chicago Board of Trade January soyabeans were down 8-1/4 cents at $9.85 per bushel.
December corn was down 4 cents at $3.45 a bushel after dipping to $3.44-1/4, its lowest since Oct. 13. December wheat was up 1-1/2 cents at $4.15-3/4.
Soyabeans sagged on worries that the US Department of Agriculture next week might raise its forecast of the US soyabean yield from its current estimate of 51.4 bushels per acre (bpa), already a record-high. The USDA's next monthly supply/demand report is due on Nov. 9.
Commodity brokerage INTL FCStone late on Tuesday raised its soyabean yield estimate to 52.8 bpa, from 52.5 last month. The firm also raised its corn yield estimate to 175.3 bpa, from its October figure of 175.2.
Pressure also stemmed from declines in global equity prices and the dollar, as investors were rattled by signs the US presidential race was tightening just days before the vote.
Some traders exited positions, triggering long liquidation in soyabeans and short-covering in CBOT wheat.
Corn fell despite supportive weekly US ethanol data. The US Energy Administration showed an increase in production and smaller stockpiles of corn-based ethanol in the latest week.
Wheat firmed on short-covering, with the December contract reaching $4.20-1/4 a bushel, its highest level in nearly two weeks, before paring gains.
Commodity funds hold a large net short position in CBOT wheat, leaving the market susceptible to bouts of short-covering.