BEIJING, March 6 (Reuters) - Chicago soybean and corn futures were flat on Wednesday, and hovered near three-year lows, ahead of a key USDA report with traders anticipating large South American harvests.

Wheat slipped after ending lower in the previous session.

FUNDAMENTALS

* The most-active soybean contract on the Chicago Board of Trade (CBOT) held its ground at $11.49-1/2 a bushel by 0236 GMT.

* CBOT corn was flat at $4.26-1/2 a bushel.

* Wheat fell 0.5% to $5.48-1/4 a bushel.

* Traders are awaiting the U.S. Department of Agriculture's (USDA) monthly supply-and-demand report on Friday to assess the latest estimates on corn and soy production in South America.

* Analysts on average expect the USDA to lower its estimate for Brazil's soybean harvest to 152.28 million metric tons and Argentina's harvest to 50.23 million metric tons, a Reuters poll showed.

* Chinese importers are believed to have purchased at least 65,000 metric tons of animal feed corn from Ukraine in deals on Monday, European traders said on Tuesday.

* Rainfall in Argentina is set to become less frequent as the El Nino weather phenomenon subsides, giving way to a drier autumn and the possibility of a La Nina climate pattern, the Buenos Aires Grains Exchange said on Tuesday.

* The El Nino weather pattern has begun to weaken, but will continue to fuel above-average temperatures across the globe, the World Meteorological Organization (WMO) said on Tuesday.

* Indonesia is likely to import larger volumes of wheat in 2024, compared with 10.87 million metric tons shipped last year, driven by higher demand for flour and animal feed, a senior industry official said on Tuesday.

MARKETS NEWS

* Asian equities eased in cautious trading, with Chinese stocks slipping as the lack of big stimulus measures from Beijing disappointed some investors, while gold and bitcoin eased after hitting record highs.

(Reporting by Mei Mei Chu; Editing by Sherry Jacob-Phillips)