By Jesse Newman

CHICAGO--U.S. grain and soybeans futures fell Tuesday following better-than-expected crop ratings and stalled buying across agricultural markets.

Wheat prices led the declines after the U.S. Department of Agriculture in a report Monday showed significant harvest progress made last week by growers of winter wheat. The USDA said about 55% of the winter wheat crop was harvested as of Sunday, which is slower than the five-year pace of 59%, but well ahead of the 38% collected a week earlier. A break in precipitation allowed farmers to harvest wheat crops in the eastern Midwest after rain delayed fieldwork for weeks.

Prices for the grain also declined amid evidence of heavy buying last week by hedge fund managers and others, after which buying slowed, allowing prices to retreat.

Wheat futures for July delivery sank 8 1/2 cents, or 1.4%, to $5.80 a bushel at the Chicago Board of Trade.

Corn and soybean prices also slid, pressured by stronger-than-expected crop conditions. The USDA on Monday said crop conditions for corn improved one percentage point from a week earlier, with roughly 69% of U.S. corn in good or excellent condition as of Sunday.

Meanwhile about 63% of the U.S. soybean crop was good or excellent, unchanged from the prior week, the government said. Analysts had anticipated a 2% decline for both crops.

CBOT July corn shed 6 1/4 cents, or 1.5%, to $4.12 1/4 a bushel.

CBOT July soybeans declined 13 3/4 cents, or 1.3%, to $10.20 a bushel.

Write to Jesse Newman at jesse.newman@wsj.com

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