GRAINS-Corn at 7-month high after USDA shows smaller stockpiles

(New throughout, adds USDA crop report data, comments; changes byline, dateline, previously LONDON)

CHICAGO, March 8 (Reuters) - U.S. corn futures jumped about 1 percent to a seven-month high on Thursday after the Department of Agriculture showed smaller-than-expected stockpiles in the wake of increased exports and demand for ethanol, traders said.

Chicago Board of Trade wheat and soybean futures were mostly lower following the midday monthly USDA data that predicted larger-than-expected U.S. ending stocks for each crop, due in part to reduced exports.

CBOT May corn futures were up 4-3/4 cents at $3.92 per bushel, highest since Aug. 15, as of 11:48 a.m. CST (1748 GMT).

CBOT May soybean futures eased 5-1/2 cents to $10.59-3/4 per bushel and CBOT May wheat down 2-1/2 cents to $4.94-3/4.

"The (corn) exports were eye-popping," said Midwest Marketing Solutions analyst Brian Hoops. "They jumped 125 million bushels last month and another 175 million bushels this month. That's a big swing, when exports are running behind last year's pace."

U.S. corn export sales have spiked so far this year after dry and hot conditions took a toll on the crop in Argentina, the No. 3 global corn and soy exporter.

The USDA slashed its outlook for Argentina corn and soy production but increased its estimate for soy production in Brazil, the top global soy producer and exporter.

"Argentine soybeans were at 47 million tonnes," said MaxYield Cooperative analyst Karl Setzer. "We did cut off 7 million tonnes from February but according to everybody you talk to, as long as we hold above 44 million tonnes it's not going to impact global balance sheets long term because that's what they need to meet demand."

Separate USDA weekly data released at midmorning on Thursday showed U.S. corn exports last week at 1.9 million tonnes and soybean sales of 2.7 million tonnes - both above the range of analyst expectations. Weekly sales of 428,400 tonnes of U.S. wheat were within the range of estimates. (Additional reporting by Karl Plume in Chicago and Mark Weinraub in Washington; Editing by Bill Trott)