Chicago wheat prices fell to a one-week low on Monday as the strong pace of exports from the Black Sea region kept the market on the defensive.

Corn prices eased and soybeans edged higher ahead of a monthly supply and demand report from the U.S. Department of Agriculture due on Thursday at 1600 GMT.

The most active wheat contract on the Chicago Board of Trade (CBOT) was down 0.6% at $5.63-3/4 a bushel by 1055 GMT after touching its weakest since Sept. 2 at $5.62 a bushel.

Corn fell 0.4% at $4.04-3/4 a bushel while soybeans rose 0.45% to $10.09-1/2 a bushel.

Dealers said exporters of Russian wheat continued to offer supplies at very competitive prices while the pace of shipments from Ukraine also remained strong.

Ukraine's grain exports in the 2024/25 July-June season have risen to 7.6 million metric tons as of Sept. 9, from 5.1 million tons by the same date of the previous season, agriculture ministry data showed on Monday.

The volume included 4.1 million tons of wheat.

"The increase was largely driven by wheat exports, which almost doubled from last year," ING said in a note.

Analyst APK-Inform has increased its forecast for Ukraine's 2024/25 July-June wheat exports to 13.8 million metric tons from 13.4 million tons, the consultancy said on Monday.

Dealers noted, however, quality concerns in Ukraine, which could curb milling wheat exports.

Wheat prices continued to be underpinned by poor harvests in western Europe. France has been particularly hard hit and is expected to yield the smallest volume in more than 40 years.

Brazilian soybean farmers could produce 14% more in the 2024/2025 season than in the previous one, a Reuters poll of 10 analysts and market institutions showed, with more rain expected in the last quarter of the year.

Large speculators trimmed their net short position in Chicago Board of Trade corn futures in the week to Sept. 3, regulatory data showed on Friday.

The Commodity Futures Trading Commission's weekly commitments of traders report also showed that non-commercial traders, a category that includes hedge funds, trimmed their net short position in CBOT wheat and trimmed their net short position in soybeans.

(Reporting by Nigel Hunt Additional reporting by Naveen Thukral in Singapore Editing by David Goodman)