GRAINS-U.S. corn in longest losing streak since mid-2010

* Snow, rains ease concerns about U.S. red winter wheat

* Outlook for corn prices bearish on record harvest f'cast

* Soybeans gain, stay above key technical level

(Adds quotes, updates prices)

LONDON/NEW DELHI, Feb 12 (Reuters) - U.S. corn prices fell on Tuesday for the eight straight session in their longest losing streak since June 2010 on a potential rebound in world grain supply this year.

Chicago wheat prices also edged lower, following a 2 percent drop in the previous session as reports of rain and snow in the drought-hit U.S. Plains outweighed support from a cut to U.S. wheat stocks in U.S. Department of Agriculture data on Friday.

"The USDA report was potentially quite bullish if you isolated the U.S. element of the statistics. But at a global level, the balance sheets were somewhat eased, which is essentially what the market took hold of. The slightly better Argentine weather is the other price driver," said Rory Deverell, commodity analyst at FCStone.

"With a pretty good outlook in South America and U.S. statistics currently, even though they're very early, suggesting the U.S. could recover their stocks as well, it could be the start of a longer term bear market."

March corn fell 0.78 percent to $6.96-3/4 a bushel by 1211 GMT, after closing down 0.95 percent on Monday. It earlier fell to $6.93-3/4 a bushel, its lowest level since January 11.

Chicago Board of Trade March wheat had dropped 0.44 percent to $7.38-1/4 a bushel, having shed 2 percent the session before. It hit an intraday trough of $7.36-1/2 a bushel, also a one-month low.

Milling wheat futures in Paris were also lower with March off 2 euros or 0.81 percent at 244.25 euros a tonne.

But March soybeans gained 0.37 percent to $14.36-3/4 a bushel. They settled at $14.31-1/2 a bushel on Monday, just above their 30-day moving average after briefly dropping below that technical level during the session.

On Friday, the U.S. Department of Agriculture cut its U.S. soybean end-of-season stocks forecast to 125 million bushels, below the market consensus.

RECORD U.S. CORN OUTPUT EXPECTED

The needed moisture for U.S. wheat crops came as the expectations of large corn and soybean harvests in South America were already weighing on grain markets.

"The most obvious reason behind (the fall in prices of) wheat is some improvement in weather conditions in the U.S. where many people were expecting a good deal of damage to the red winter crop due to the dry winter," said Jonathan Barratt, chief executive of BarrattBulletin, a Sydney-based commodity research firm.

The U.S. Department of Agriculture projects U.S. corn output to rise 34 percent to a record 14.4 billion bushels this year, assuming a return to normal weather and yields after droughts stunted output in 2012.

Farmers will harvest the second-largest soybean crop on record at 3.335 billion bushels and a medium-sized wheat crop of 2.19 billion bushels, the USDA said.

Prospects for large South American crops caused Goldman Sachs to cut its price forecasts for both corn and soybeans. The investment bank also lowered its outlook for wheat prices due to low demand for U.S. exports.

Australia, the world's second-largest wheat exporter, also slightly raised its production forecast for the current marketing year from its December estimate, as the crop largely escaped damage from a heat wave and floods this summer.

(Additional reporting by Gus Trompiz in Paris; editing by Jason Neely)