GRAINS-Soybeans slip further as market readies for U.S. crop report

* Trade worries, big U.S. crop keep soybeans under pressure

* Market awaits USDA supply/demand report at 1600 GMT

* Soy, corn, wheat all ease to lowest in over a week

(Updates with European trading, changes byline/dateline) PARIS/SYDNEY, Oct 11 (Reuters) - Chicago soybean futures fell for a third straight session on Thursday as an expected bumper U.S. harvest and worries over a prolonged trade dispute between Washington and Beijing pressured prices. Soybeans and corn each touched a 10-day low before the U.S. Department of Agriculture's (USDA) monthly supply-and-demand outlook that is expected to again raise estimates for U.S. harvest yields. Steep losses on stock markets, partly linked to investor concern over the impact of trade tensions, also kept attention on the U.S.-China stand-off which has led to a tailing off in U.S. soybean shipments to China. The most active soybean futures on the Chicago Board Of Trade were down 0.4 percent at $8.48-3/4 a bushel by 1151 GMT. It earlier slipped to $8.47, its weakest since Oct. 1. "Negative momentum remains," said Tobin Gorey, director of agricultural strategy, Commonwealth Bank of Australia. "The USDA updates U.S. and global inventory estimates tonight and that will determine whether it can be broken." The USDA is expected to raise its U.S. corn and soybean yield and production forecasts and increase its end-of-season U.S. and global stocks projections for corn, soy and wheat. The prospect of bumper yields has curbed prices even in the face of torrential rain in parts of the Midwest and U.S. Plains that is disrupting harvesting of corn and soybeans, while also threatening to wash away some fields of newly planted wheat. The most active CBOT corn futures eased 0.5 percent to $3.61 a bushel, after reaching its lowest since Oct. 1 at $3.60-3/4. CBOT wheat was down 0.2 percent at $5.09-1/2 a bushel, after earlier touching its lowest since Oct. 2 at $5.08-1/4. Upward revisions to production in Russia were easing worries about tightening supply in the world's top wheat exporter. Consultancy Sovecon on Thursday raised its estimate of the 2018 Russian wheat crop to 69.8 million tonnes from 69.0 million tonnes. However, the Rosario grains exchange on Wednesday reduced its estimate of Argentina's upcoming wheat harvest to 19 million tonnes from 21 million previously, which could reduce the country's capacity to make up for a reduced surplus in other exporting zones.

Prices at 1151 GMT

Last Change Pct End Ytd Pct Move 2017 Move CBOT wheat 509.50 -1.00 -0.20 427.00 19.32 CBOT corn 361.00 -1.75 -0.48 350.75 2.92 CBOT soy 848.75 -3.50 -0.41 961.75 -11.75 Paris wheat Dec 202.00 -0.75 -0.37 170.00 18.82 Paris maize Nov 173.00 -0.25 -0.14 165.25 4.69 Paris rape Nov 370.00 -0.75 -0.20 352.75 4.89 WTI crude oil 71.85 -1.32 -1.80 60.42 18.92 Euro/dlr 1.16 0.01 0.47

Most active contracts - Wheat, corn and soy US cents/bushel, Paris futures in euros per tonne

(Reporting by Colin Packham; editing by Richard Pullin and Alexander Smith)