GRAINS-Corn falls, adverse weather outlook underpins weekly gains

(Updates prices, adds details, changes dateline/byline)

* Corn extends losses but set to finish week up 2.5 percent

* Soybeans fall, on course for weekly gains

* Wheat poised to extend weekly losses in second week

SYDNEY/PARIS, July 21 (Reuters) - U.S. corn fell below $4 a bushel on Friday as traders took profits at the end of a week where corn was on track to gain around 2.5 pct in response to forecasts for continued adverse weather which added to fears of production losses. Soybeans were also set to post a weekly gain despite a dip on Friday, while wheat was on course to post its second straight weekly loss. The most active corn futures on the Chicago Board Of Trade were down 1.3 percent to $3.99-1/2 a bushel after closing up 2.1 percent on Thursday when prices hit a high of $4.06-3/4 a bushel - the highest since July 12. "Weather forecasts are still the driving force on the Chicago soybean and maize markets. The lack of rainfall and hot temperatures are the main focus, suggesting a further cuts in the USDA's crop ratings," consultancy Agritel said in a note. Recent dry weather has already damaged crops, data from the U.S. Department of Agriculture earlier this week showed. Corn crop condition ratings declined earlier this week in top-producing states of Iowa, Illinois and Nebraska, and extended outlooks for limited rainfall could lead to further downgrades. Agritel also pointed to concern about spring crop conditions in Canada, where many areas are still very dry, with hot weather and no rain in sight. The most active soybean futures were down 0.7 percent to $10.19-1/2 a bushel after closing up 1.4 percent on Thursday. Soybeans are up nearly 1.8 percent on the week after posting weekly losses of 1.4 percent in the previous week. The most active wheat futures were 0.15 percent higher at $5.06-1/2 a bushel after closing up 0.5 percent in the previous session. Wheat is still down 0.8 percent on the week, after falling 4.5 percent last week. The U.S. Department of Agriculture early on Thursday reported weekly wheat export sales of 669,500 tonnes, well above trade forecasts that ranged from 250,000 to 450,000 tonnes.

Prices at 1100 GMT

Last Change Pct End Ytd Move 2016 Pct


CBOT wheat Mar 506.50 0.75 0.15 408.00 24.14 CBOT corn Mar 399.50 -5.25 -1.30 352.00 13.49 CBOT soy Mar 1019.50 -7.50 -0.73 1004.00 1.54 Paris wheat Dec 177.25 0.50 0.28 171.00 3.65 Paris maize Nov 168.50 0.00 0.00 170.00 -0.88 Paris rape Aug 367.00 0.00 0.00 407.50 -9.94 WTI crude oil 46.54 -0.38 -0.81 53.72 -13.37 Euro/dlr 1.16 0.00 0.14

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

(Reporting by Colin Packham. Editing by Jane Merriman)