GRAINS-Soy, corn firm on broad commodity strength, U.S. soy sales

(New throughout; updates prices, adds quotes, changes byline, changes dateline from previous PARIS/SINGAPORE) CHICAGO, Sept 20 (Reuters) - U.S. soybean futures rose on Wednesday, buoyed by strength in commodities and resurgent soy export demand, traders said. Wheat and corn followed the firm trend, with both grains rebounding after a two-session slide as the U.S. corn harvest reached the Midwest. As of 1:05 p.m. CDT (1805 GMT), Chicago Board of Trade November soybeans were up 4-1/4 cents at $9.69-3/4 per bushel. December corn was up 1-1/2 cents at $3.49-3/4 a bushel and December wheat was up 5-1/2 cents at $4.48-1/2 a bushel. Soybeans hit a session high after the U.S. Department of Agriculture said private exporters sold 1.2 million tonnes of U.S. soybeans, including 1.08 million tonnes to unknown destinations. The USDA said the soybean sale was among the top 10 largest ever announced through its daily reporting system, which dates to 1977. Analysts suspected that at least a portion of the sales to unknown destinations were earmarked for China, which is by far the world's largest soy importer. "It's harvest time. This is the time where China has to be active in buying soybeans. They are under-covered for October and November," said Don Roose, president of U.S. Commodities. U.S. soybean export commitments so far in the 2017-18 marketing year that began Sept. 1 are lagging the year-ago pace, and the USDA has forecast record-large U.S. soybean imports for the year. "First we have got to get caught up with last year, before we talk about going to a new record. So these are the type of numbers we need," Bill Nelson, an analyst with Doane Advisory Services, said of the sales announcement. CBOT grains and soy drew light support from strength in other commodities, including U.S. crude oil futures, which were up about $1 a barrel, or 2 percent. The 19-market Thomson Reuters CoreCommodity Index was up 1.2 percent after reaching its highest level since May. Wheat rose about 1 percent on technical buying and short-covering, but the bellwether December contract struggled to push much above $4.50 a bushel, an area of stiff chart resistance over the past week. Corn rose, but the CBOT December contract stayed inside of Tuesday's trading range. Traders were eyeing support at the contract low of $3.44-1/4 a bushel set on Aug. 31, as they awaited yield reports from the U.S. corn harvest expanding in the heart of the Midwest.

CBOT prices as of 1:07 p.m. CDT (1807 GMT):

Net Pct Volume

Last change change

CBOT wheat WZ7 448.25 5.25 1.2 52792 CBOT corn CZ7 350.00 1.75 0.5 90790 CBOT soybeans SX7 969.75 4.25 0.4 73177 CBOT soymeal SMZ7 310.90 2.20 0.7 30084 CBOT soyoil BOZ7 34.71 -0.05 -0.1 47917

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 and Sybille de La Hamaide in Paris; Editing by Christian Schmollinger and Susan Fenton)