GRAINS-Corn to 1-week low, wheat sags ahead of monthly USDA report

(New throughout; updates prices, adds quotes, changes byline, changes dateline from previous SINGAPORE) CHICAGO, Oct 11 (Reuters) - U.S. corn futures fell to a one-week low on Wednesday and wheat hit a one-month trough a day ahead of monthly U.S. Department of Agriculture reports expected to confirm big crops and plentiful global grain supplies, analysts said. Soybeans were lower but trade was choppy. As of 12:40 p.m. CDT (1715 GMT), Chicago Board of Trade December corn was down 2-1/4 cents at $3.47 per bushel, December wheat was down 1 cent at $4.34-1/4 a bushel and November soybeans were down 1/2 cent at $9.65-1/2 a bushel. Corn dipped to $3.46 and hovered near its contract low of $3.44-1/4, set Aug. 31, anchored by plentiful supplies and expectations that the USDA will raise its estimate of the U.S. corn harvest in its supply/demand reports on Thursday.

"The expectations for this report, with a higher yield in corn, have got us under pressure," said Ted Seifried, chief market strategist with Zaner Ag Hedge. Rains slowed the U.S. Midwest harvest in recent days. The USDA in a weekly crop progress report said the corn harvest was 22 percent complete, lagging the five-year average of 37 percent. The soybean harvest was 36 percent complete, behind the five-year average of 43 percent. The corn harvest was only 8 percent finished in Iowa, the top U.S. corn state, and 4 percent complete in Minnesota, the No. 4 producer. Yet the futures market seemed unconcerned. "We are way behind up here and it has people nervous. But eventually you get it harvested. It's more a function of what the size of the crop is going to be," said Mark Schultz, chief analyst at Minnesota-based Northstar Commodity Investment Co. Some analysts noted that the USDA's crop condition ratings improved for both corn and soybeans, a possible sign of rising yield prospects. CBOT wheat fell on technical selling, with the December contract dipping to $4.29-3/4, its lowest since Sept. 12. The CBOT and K.C. December wheat contracts were both less than 12 cents above their respective contract lows. The USDA confirmed that private exporters in the last day sold 104,202 tonnes of U.S. hard red winter wheat and 150,000 tonnes of corn to Mexico. Exporters also sold 264,000 tonnes of soybeans to China and another 132,000 tonnes of soy to unknown destinations. "While this was in fact positive news, the fact that yearly sales trail expectations (is) limiting market response," MaxYield Cooperative analyst Karl Setzer wrote in a note.

CBOT prices as of 12:39 p.m. CDT (1739 GMT):

Net Pct Volume

Last change change

CBOT wheat WZ7 434.00 -1.25 -0.3 57801 CBOT corn CZ7 347.00 -2.25 -0.6 111643 CBOT soybeans SX7 965.50 -0.50 -0.1 104531 CBOT soymeal SMZ7 315.30 -0.90 -0.3 23346 CBOT soyoil BOZ7 33.17 0.06 0.2 28909

NOTE: CBOT December wheat, December corn and November soybeans shown in cents per bushel, December soymeal in dollars per short ton and December soyoil in cents per lb.

(Additional reporting by Naveen Thukral in Singapore; Editing