GRAINS-Wheat stays weak as brimming supplies hang over market

* Wheat down for 3rd day, IGC raises world stocks outlook

* Stronger dollar underlines tough export context

* Corn, soy markets assess U.S. harvest, S. America planting

* Soybeans underpinned by strong export demand

(Updates with European trading, changes byline/dateline) PARIS, Oct 27 (Reuters) - Chicago wheat futures eased on Friday for a third consecutive session as high global supply and stiff export competition encouraged profit-taking after this week's rally. Soybeans were little changed with strong demand underpinning the oilseed market and countering supply pressure as the U.S. harvest progresses and rainfall in Brazil eases concerns about planting. Corn edged lower as the cereal market also faced abundant supply although traders were monitoring cold weather forecasts that could hamper a U.S. corn harvest that has been advancing more slowly than for soybeans. The most active Chicago Board Of Trade (CBOT) wheat futures were down 0.4 percent at $4.30-1/4 a bushel by 1225 GMT. CBOT corn was down 0.2 percent at $3.49-3/4 a bushel while soybeans inched up 0.2 percent to $9.73-1/4. The International Grains Council lifted its forecast for 2017/18 world grain production on Thursday, mainly due to an increased estimate of the U.S. corn crop. But the inter-governmental body also estimated that wheat inventories would swell to a record level this season while corn and soybean stocks would ease, Commerzbank said. "In other words, while the corn and soybean markets tighten, the wheat supply situation remains ample," the bank's analysts said in a note. A three-month high for the dollar against a range of currencies could hamper U.S. wheat export prospects just as it faces intense competition due to the ample global supply. Traders will be watching the results of a wheat tender by Saudi Arabia this weekend to gauge the competitiveness of different export origins. Soybean prices have lost some impetus as rain in Brazil has curbed dryness in major growing areas as the planting season continues. "Soybean prices are losing the weather premium added because of Brazil's dry soybean regions," said Tobin Gorey, director of agricultural strategy at Commonwealth Bank of Australia. Strong demand for soybeans provided a floor under the market. The U.S. Agriculture Department on Thursday morning reported weekly soybean export sales of 2.13 million tonnes, topping forecasts that ranged from 1.3 million to 1.7 million tonnes. In Argentina, soy planting began over the last two weeks while flooding contributed to a 5.7 percent contraction in projected area for the 2017/18 season compared with the previous crop year, the Buenos Aires Grains Exchange said on Thursday.

Grain markets were also assessing the risk of harvest delays from rain and snow in the United States, although damage to crops was expected to be limited.

Prices at 1225 GMT

Last Change Pct End Ytd Pct Move 2016 Move CBOT wheat 430.25 -1.50 -0.35 408.00 5.45 CBOT corn 349.75 -0.75 -0.21 352.00 -0.64 CBOT soy 973.25 2.00 0.21 1004.00 -3.06 Paris wheat Dec 163.00 0.50 0.31 175.00 -6.86 Paris maize Nov 151.50 0.75 0.50 170.00 -10.88 Paris rape Nov 368.50 0.00 0.00 383.25 -3.85 WTI crude oil 52.36 -0.28 -0.53 53.72 -2.53 Euro/dlr 1.16 0.00 -0.34

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 Sunil Nair and Edmund Blair)