GRAINS-Soybeans stay firm on big China demand, expected U.S. yield cut

* January soybeans top $10 in 4th straight daily gain

* China raises import forecast, signs more U.S. deals

* USDA report seen bringing cut to U.S. yield estimate

* Corn flat, wheat down a touch in pre-report tweaks

(Updates with European trading, changes dateline) PARIS, Nov 9 (Reuters) - Chicago soybeans rose for a fourth session on Thursday to test the $10 threshold as newsflow from China underlined buoyant demand, while traders braced for monthly U.S. government forecasts expected to show a cut to the U.S. soybean yield. Corn was flat and wheat down slightly as investors adjusted positions before the U.S. Department of Agriculture's (USDA) widely followed supply-and-demand report at 1700 GMT. The most-active soybean contract on the Chicago Board Of Trade was up 0.4 percent at $10.02-1/4 a bushel by 1250 GMT, after earlier setting a near four-week high at $10.03. Corn was unchanged on the day at $3.48-1/4 a bushel while wheat inched down 0.2 percent to $4.26 a bushel. Expectations that the USDA will trim its estimate of this year's U.S. soybean yield for the second month in a row have supported prices this week. "If the USDA makes a more sizeable cut to the soybean yield than people are expecting then we could see prices climb," a European trader said. "But funds are long on soybeans and short on corn so there is the chance there could be a bigger move in corn." News from China also put the spotlight on strong demand for soybeans. The United States soybean industry has signed two letters of intent with Chinese importers covering a $5 billion purchase of an additional 12 million tonnes of soybeans in the 2017/18 marketing year, deals announced during President Donald Trump's visit to Beijing. The Chinese government raised its forecast for soybean imports in the 2017/18 crop year to 95.97 million tonnes from 94.5 million previously, boosted by strong crushing demand.

The upward revision put in perspective a slowdown in Chinese imports in October, linked to weather disruption in the United States. There was also potentially positive demand news from China for the U.S. corn market, with China announcing it would remove value-added tax on imports of distillers dried grains (DDGS), a by-product of corn-based ethanol. The USDA report is also expected to confirm ample global supplies of wheat, although traders will be watching for any further cuts to weather-affected production in Australia. A latest purchase of Russian wheat by Egypt's state buyer GASC on Wednesday underlined stiff competition, while news that India has doubled its wheat import tax suggested the country would wind down imports. U.S. grain markets will get an update on export demand from weekly U.S. export sales data published at 1330 GMT.

Prices at 1250 GMT

Last Change Pct End 2016 Ytd Pct Move Move CBOT wheat 426.00 -0.75 -0.18 408.00 4.41 CBOT corn 348.25 0.00 0.00 352.00 -1.07 CBOT soy 1002.25 3.75 0.38 1004.00 -0.17 Paris wheat Dec 161.25 0.75 0.47 175.00 -7.86 Paris maize Nov 158.50 0.00 0.00 171.00 -7.31 Paris rape Nov 385.75 -0.50 -0.13 393.00 -1.84 WTI crude oil 56.91 0.10 0.18 53.72 5.94 Euro/dlr 1.16 0.00 0.30

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

(Reporting by Gus Trompiz and Naveen Thukral; Editing by Gopakumar Warrier and Edmund Blair)