GRAINS-Wheat, soy extend losses on technicals, U.S. weather

(Updates prices, adds analyst comments; changes byline, dateline, previous PARIS/SINGAPORE) CHICAGO, Aug 14 (Reuters) - U.S. grain and soy futures fell further on Monday as technical selling and outlooks for favorable crop weather continued to pressure prices following steep declines last week.

MGEX spring wheat futures plummeted by about 4 percent, with the September contract shedding 25-1/2

cents to a nearly two-month low of $6.48-1/2 per bushel. More actively traded Chicago Board of Trade (CBOT) wheat eased 3-3/4 cents to $4.35-1/2 per bushel at 11:45 a.m. CDT (1645 GMT).

CBOT November soybeans were down 11-3/4 cents to $9.33-1/2 and CBOT December corn off 2-3/4 cents to $3.72.

The losses came in the wake of a monthly U.S. Department of Agriculture (USDA) report on Thursday that showed bigger-than-expected U.S. corn and soybean yield estimates and a smaller-than-expected cut in the spring wheat crop. Rainfall this week should also benefit crops. About 70 percent of U.S. corn- and soybean-growing areas should receive rains in the next five days, according to the Commodity Weather Group. "We took a lot of wind out of the sails for the bulls on Thursday. We're seeing some follow-through selling today," said Jack Scoville, broker at the Price Futures Group. Steep declines in MGEX spring wheat were likely speculative investors liquidating long bets following the USDA report last week. Spring wheat surged to a two-year high of more than $8 per bushel in early July amid drought conditions in the northern United States, enticing investors into the relatively thinly traded wheat contract, before prices started to retreat. "The specs got long and for the last few days, that's the worst place to be," Scoville added. USDA weekly data due after the close of trading was expected to show unchanged condition ratings for the U.S. corn and soy crops and slightly lower condition ratings for spring wheat, according to analysts surveyed by Reuters. Analysts also expected the National Oilseed Processors Association on Tuesday to show a year-on-year decline in the U.S. soybean crush in July.

(Additional reporting by Naveen Thukral in Singapore and Gus Trompiz in Paris; editing by G Crosse)