GRAINS-Corn futures hit three-week low; wheat dips, soy choppy

Updates prices, adds quotes, paragraphs 5 and 10, changes byline, changes dateline from PARIS/CANBERRA

By Julie Ingwersen

CHICAGO, Feb 25 (Reuters) - U.S. corn futures fell to a three-week low on Tuesday, sliding for a third successive session on tariff tensions and improving weather outlooks for South American crop regions, analysts said.

Wheat followed corn lower as weather threats to Northern Hemisphere winter crops diminished, while soybean futures were narrowly mixed in choppy trade.

As of 1:10 p.m. CST (1910 GMT), Chicago Board of Trade May corn CK25 was down 3-1/4 cents at $4.93-3/4 a bushel after falling to $4.88-1/2, its lowest since February 3. CBOT May wheat WK25 was down 6 cents at $5.87-1/2 a bushel while May soybeans SK25 were up 1 cent at $10.48-1/2 a bushel.

Commodity funds held a massive net long, or bought, position in CBOT corn futures, according to the U.S. Commodity Futures Trading Commission's last weekly commitments report, leaving the market vulnerable to bouts of long liquidation.

"I think we are seeing a little bit of hot air coming out of the Board, with the managed money still net long a very large amount," said Terry Reilly, senior agricultural strategist with Marex.

In South America, rains in Argentina were bringing relief to corn and soy crops that have struggled with drought. Showers were likely to continue over the next few days and mark an "inflection point" for the current soybean and corn crops, the Rosario grains exchange said on Monday.

Meanwhile, renewed investor concerns about U.S. tariffs, after President Donald Trump said proposed levies on imports from Mexico and Canada were on track to be implemented, were also weighing on grain markets given fear of reprisals against U.S. agricultural exports.

Grain traders were also turning their attention to a U.S. Department of Agriculture conference later this week at which the USDA will give early supply and demand projections for next season.

Wheat futures fell on milder weather in top global wheat supplier Russia and the United States.

"The Black Sea area has warmed up. There is no winterkill threat over there anymore," said Tom Fritz, a partner with EFG Group in Chicago.

Grain consultancy Sovecon raised its forecast for 2025/26 Russian wheat exports to 38.9 million metric tons, from 38.3 million tons previously, but lowered its export forecast for 2024/25 to 42.2 million metric tons.