GRAINS-Wheat to 1-week low on improving U.S. weather; corn, soy sag

(New throughout; updates prices, adds quotes, changes byline, changes dateline; previous PARIS/SYDNEY) CHICAGO, April 13 (Reuters) - U.S. wheat futures fell on Friday to a one-week low, pressured by forecasts for much-needed rain late next week in the southern Plains winter wheat belt, analysts said. Corn followed wheat lower amid a lack of fresh supportive news, and soybeans turned down, erasing early advances, as nervous traders booked profits ahead of the weekend. As of 11:48 a.m. CDT (1648 GMT), Chicago Board of Trade May wheat was down 11 cents at $4.70 per bushel, after dipping to $4.69-3/4, its lowest since April 6. May corn was down 3-1/2 cents at $3.85-1/4 a bushel and May soybeans were down 6-1/4 cents at $10.54-1/2 a bushel. Wheat slid for a third straight session as traders assessed prospects for showers late next week in the southern Plains, where the region's hard red winter wheat is developing amid drought conditions. Updated forecast models shifted the track of a storm expected next Friday slightly to the north, the Commodity Weather Group said in a client note, but it could still generate beneficial moisture. "The story is, you've got some moisture coming in. It's not going to break the drought, but it doesn't take a lot of water to get a crop. And export sales were not good," said Alan Brugler, president of Nebraska-based Brugler Marketing. The U.S. Department of Agriculture (USDA) on Thursday reported export sales for old and new crop U.S. wheat in the latest week at 188,700 tonnes, below trade expectations.

This came after the USDA on Tuesday raised its forecast of U.S. 2017/18 wheat ending stocks by more than expected, and increased its outlook for world wheat stocks to an all-time high. Soybeans turned lower on profit-taking after the spot May contract touched $10.67-1/4, its highest in a month, buoyed by demand from exporters and domestic crushers and worries about the drought-hit Argentine soy harvest. "I think it's just profit-taking. The fundamental stories are still fairly bullish, with the shrinking South American crop," Brugler said. Argentina, the world's No. 3 soybean producer, has struggled with a drought that has slashed its crop. However, yield prospects are bright in neighboring Paraguay and Brazil. Paraguay will produce just over 10 million tonnes of soybeans in 2017/18, slightly less than a year earlier, the national export chamber CAPECO said on Thursday. "These yields will go a long way in offsetting the losses that are being reported in Argentina," Karl Setzer, analyst with Iowa-based MaxYield Cooperative, said in a note to clients.

CBOT prices as of 11:48 a.m. CDT (1648 GMT):

Net Pct Volume

Last change change

CBOT wheat WK8 470.50 -10.50 -2.2 48946 CBOT corn CK8 385.25 -3.50 -0.9 162799 CBOT soybeans SK8 1054.50 -6.25 -0.6 80480 CBOT soymeal SMK8 382.60 -0.80 -0.2 27071 CBOT soyoil BOK8 31.55 -0.08 -0.3 24932

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

(Additional reporting by Gus Trompiz in Paris and Colin Packham in Sydney; Editing by David Evans and Dan Grebler)