CBOT grain, soybean futures ease as questions over Brazil crop remain

* Projections for U.S. corn usage increased -USDA

* Weakness in wheat curbed by Russia-Ukraine tensions

* USDA left Brazil's soybean crop forecast unchanged

(Recasts throughout with new headline, bullets, analyst quote; updates prices as of 1705 GMT; previous dateline PARIS/SINGAPORE; changes byline)

CHICAGO, April 11 (Reuters) - Chicago corn futures turned lower on Thursday, after the U.S. Department of Agriculture forecast domestic supplies of the grain would tick lower and anticipated more would be used for producing ethanol and animal feed.

Wheat edged lower, though tensions in the Black Sea region kept a floor under the market. Soybean futures also eased.

Much of the session's trade was focused on USDA's monthly supply and demand report, which stood firm on its forecast for hefty South America's corn and soybean production.

The agency continued to paint a different picture of the Brazilian harvest than crop agency Conab. Earlier in the day, Conab reduced output projections for soy and corn, citing adverse climate in top grower Mato Grosso state for the fall in expected overall soy output and a smaller planted area for corn.

Conab said Brazil will produce 146.522 million metric tons of soybeans in the 2023/24 farm cycle, and harvest 110.964 million tons of corn. But USDA put Brazil's soybean production at 155 million tons, and corn at 124 million tons, unchanged from its global supply and demand report in March.

USDA pegged domestic soybean stocks at the high end of traders' expectations, which pressured futures. Though prices soon recovered, "soybean ending stocks increasing is not a good sign for higher prices," said Jack Scoville, market analyst at The Price Futures Group.

USDA cut its forecast for Argentina's corn crop to 55 million metric tons from 56 million in March, below analysts' expectations for 55.6 million.

The most active corn contract on the Chicago Board of Trade (CBOT) was down 0.98% at $4.30 a bushel by 1705 GMT. CBOT wheat was 1.34% lower at $5.51 a bushel and CBOT soybeans eased 0.3% to $11.61.25 a bushel. (Additional reporting by Heather Schlitz in Chicago, Gus Trompiz in Paris and Naveen Thukral in Singapore; Editing by Sherry Jacob-Phillips, Shounak Dasgupta, Vijay Kishore and Richard Chang)