* March corn falls for 3rd session, cumulative loss 4 pct
* Chinese rejection of unauthorised GMO clouds demand
* Wheat toils under rising global supply
* Soybeans slip after Friday bounce from one-week low
(Updates prices, adds quotes after European trading; changes byline/dateline) PARIS/SYDNEY, Dec 16 (Reuters) - U.S. corn futures fell for a third consecutive session on Monday, bringing cumulative losses to 4 percent, on concerns China could reject more U.S. corn and hamper efforts to shift a record-large U.S. harvest. Wheat extended a slide to fresh contract lows as weakness in corn and rising global wheat supply continued to dampen sentiment. Soybeans eased as Friday's rebound from a one-week low failed to carry over. China has already rejected three cargoes of U.S. corn because of an unapproved genetically modified (GMO) variety and now U.S. exporters are concerned shipments of dried distillers' grains, a corn byproduct, may be rejected for the same reason, trade sources said. "The same issue is pressuring the U.S. corn market and that is the fear that China would continue rejecting U.S. cargoes of corn after the discovery of an unapproved genetically modified strain," said Vanessa Tan, investment analyst at Phillip Futures in Singapore. China's strict checks for an unapproved strain of GMO corn in U.S. cargoes are likely to continue until early next year as Beijing seeks to curb cheap imports and support domestic corn prices, industry sources said on Friday. "The key factor for the price trend will come from the revision or not of Chinese imports, currently forecast at 7 million tonnes," French consultancy Agritel said, referring to a U.S. government estimate of 2013/14 Chinese corn imports.
Chicago Board of Trade March corn fell 1.0 percent to $4.21-1/4 a bushel, bringing its three-day losses to 4 percent. It was just off an earlier two-week low of $4.21. Adding to pressure on corn is a proposal last week by a group of U.S. Senators to abolish a mandate for ethanol, the alternative fuel that absorbs a large amount of the U.S. corn harvest. Wheat and soybeans slipped as the crops also showed pressure from rising global supply. CBOT March wheat was down 0.7 percent at $6.24-1/4, just off an earlier contract low of $6.24. January soybeans fell 0.4 percent to $13.22-3/4 a bushel. The U.S. Department of Agriculture last week raised its outlook for global wheat inventories by 4.3 million tonnes to 182.78 million, above market expectations of 179.11 million tonnes. Soybeans have found support in relatively tight U.S. stocks but the prospect of bumper South American crops early in 2014 has eroded bullish sentiment. "Now prices must find a new equilibrium that adequately grows demand while discouraging additional global plantings in 14/15," Morgan Stanley analysts said of grain markets.
* Prices as of 1305 GMT
Product Last Change Pct Move CBOT wheat 624.25 -4.50 -0.72 CBOT corn 421.25 -4.25 -1.00 CBOT soy 1322.75 -4.75 -0.36 Paris wheat 203.25 -1.25 -0.61 Paris maize 174.75 -1.00 -0.57 Paris rape 366.25 -1.00 -0.27 WTI crude oil 97.46 0.86 +0.89 Euro/dlr 1.38 +0.30
* CBOT futures prices are in cents per bushel, Paris futures in euros per tonne, WTI crude oil in dollars per barrel.
(Editing by Muralikumar Anantharaman and Dale Hudson)