PARIS/BEIJING - Chicago soybean, corn and wheat futures fell on Tuesday as a proposed ceasefire between Israel and Iran eased war concerns while weather remained broadly favourable for U.S. crops. Oil prices tumbled on Tuesday after Donald Trump said a ceasefire has been agreed on between Iran and Israel, though the U.S. President later accused both sides of violating the accord. Iranian and Israeli media reported new Israeli airstrikes on Iran on Tuesday, despite U.S. President Donald Trump having said Israel had called them off at his command to preserve an hours-old ceasefire. The most active soybean contract slipped 0.6% to $10.40-1/2 per bushel by 1150 GMT.

Soybean byproduct soyoil , widely used in biofuel, was down 2.1% as it tracked crude oil more closely. CBOT corn eased 0.3% to $4.18 a bushel, after earlier setting a latest 2025 low at $4.16-1/4. CBOT wheat fell 1.5% to $5.60-3/4 a bushel. "Let's see if the ceasefire is real. With no geopolitics, most grains and oilseeds should be moving lower in the next one or two months," a European trader said. Grain markets remained under pressure from expectations of ample U.S. and global supply, despite weaker than anticipated weekly U.S. crop ratings. Soybean crop ratings held steady at 66% good to excellent, according to U.S. Department of Agriculture data published after Monday's close, missing average analyst expectations.

The good/excellent score for corn fell by 2 points to 70% but remained the strongest in five years for this point of the season. Ratings for both winter and spring wheat unexpectedly fell, but an advancing U.S. winter wheat harvest kept the focus on incoming supply. Analysts expect hot weather and rain forecast in the week ahead to support crop growth in the U.S. corn belt, with limited risks of heat stress. For wheat, rain in the northern U.S. Plains has improved soil moisture for spring wheat, while drier weather in the central and southern Plains favoured winter wheat harvesting, according to weather forecaster Vaisala.

Broadly favourable production prospects for wheat across the Northern Hemisphere were also weighing on the market as harvesting got going. Argus Media has increased its forecast for Russia's 2025/26 wheat production, now projecting output to reach 84.8 million tons and come well above last year's 81.3 million tons.

Egypt's state grains buyer has purchased several hundred thousand metric tons of Black Sea wheat in the past weeks for delivery in July and August, market sources told Reuters, though traders said more sustained demand from importers would be needed to change the tone of the wheat market.

Prices at 1150 GMT Last Change Pct Move CBOT wheat 560.75 -8.75 -1.54 CBOT corn 418.00 -1.25 -0.30 CBOT soy 1040.50 -6.25 -0.60 Paris wheat 201.00 -3.25 -1.59 Paris maize 195.00 -2.25 -1.14 Paris rapeseed 485.00 -14.00 -2.81 WTI crude oil 66.04 -2.47 -3.61 Euro/dlr 1.16 0.00 0.26 Most active contracts - Wheat, corn and soy US cents/bushel, Paris futures in euros per metric ton