U.S. soybean, wheat ending stocks up as exports fall -USDA

WASHINGTON, Dec 12 (Reuters) - The U.S. Agriculture Department on Tuesday raised its ending stocks forecast for domestic wheat and soybeans due to dwindling export demand for U.S. supplies.

The government also trimmed its supply view for corn due to rising usage from the ethanol sector.

In its monthly supply and demand report, USDA pegged soybean 2017/18 ending stocks at 445 million bushels, up 20 million from its November outlook. It lowered its export forecast for the oilseed by 25 million bushels and raised seed usage by 5 million bushels.

U.S. soy exporters have seen a slow start to the marketing year, with the pace of shipments lagging well behind what is needed to meet the USDA's bullish projections. Plentiful supplies from South American producers Argentina and Brazil have provided overseas buyers with alternatives to U.S. soybeans.

For wheat, U.S. ending stocks for 2017/18 were seen at 960 million bushels, up from the 935 million bushels forecast in the government's November report.

A surplus of Canadian supplies following a bigger-than-expected harvest in that key competitor has cut into demand for U.S. exports.

USDA lowered its 2017/18 domestic wheat export outlook by 25 million bushels to 975 million bushels. It raised its estimate of the Canadian wheat crop by 3 million tonnes to 30 million tonnes.

Domestic corn ending stocks for 2017/18 were cut to 2.437 billion bushels from 2.487 billion bushels. USDA raised its forecast for corn used for ethanol in the marketing year to 5.525 billion bushels from 5.475 billion bushels.

USDA cited increased sorghum exports as the reason for more corn being used for ethanol.

Analysts had been expecting corn ending stocks of 2.478 billion bushels, soybean ending stocks of 438 million bushels and wheat ending stocks of 938 million bushels, according to the average of estimates given in a Reuters poll. (Reporting by Mark Weinraub; Editing by Andrea Ricci)