BEIJING, June 29 (Reuters) - Chicago soybean and corn futures fell on Monday, while wheat traded almost flat, as traders adjusted positions ahead of the U.S. Department of Agriculture's quarterly grain stocks report on Tuesday.

FUNDAMENTALS

* The most-active soybean contract on the Chicago Board of Trade (CBOT) Sv1 was down 0.56% at $11.49-3/4 a bushel, as of 0127 GMT, while corn Cv1 fell 1.02% to $4.37 a bushel. Wheat Wv1 was up 0.04% at $5.9 a bushel.

* The U.S. Department of Agriculture is set to release its quarterly grain stocks report at 12 p.m. EDT (1600 GMT) on Tuesday, June 30.

* Analysts polled by Reuters expect June 1 stocks of wheat, soybeans and corn to rise year-on-year, and see farmers planting about 85.4 million acres of soybeans and 95 million acres of corn.

* Weather concerns lent some support to the grain markets. Hotter-than-normal conditions are expected from the Plains to the Atlantic Coast through July 4, the National Weather Service said last week.

* Wheat faced pressure from the ongoing U.S. Plains harvest and ample global supplies.

* In Brazil, farmers had harvested 18.9% of the expected 2026 second corn area, compared with 19.4% at the same time last year, Patria Agronegocios said.

* Commodity funds were net sellers of CBOT wheat futures, traders said on Friday. CBOT/FUNDS

DATA/EVENTS (GMT)

0900 EU Consumer Confid. Final Jun