Private analytical firm Informa Economics on Friday became the latest crop forecaster to cut its outlook for the 2012 U.S. corn and soybean harvests due to poor weather, according to traders.

Informa's downward adjustment in corn and soybean production levels is based on the assumption that August will continue the stressful weather experienced thus far in the 2012 growing season.

The data were released as a special update on U.S. corn and soybeans assuming unfavorable August weather. Informa will release its normal August production report based on surveys on Aug. 3.

Informa lowered its estimate for the U.S. corn harvest to 11.475 billion bushels from its early-July estimate of 12.49 billion bushels, traders said. The firm cut its yield estimate for the crop to 134 bushels an acre from its previous estimate of 142.5 bushels an acre, they said.

"The stressful weather pattern the U.S. is experiencing has been reducing crop prospects on a daily basis," Informa said in the report.

Grain users are uncertain about the size of the upcoming autumn harvests after intense heat stressed the crops. Farmers need to harvest a big corn crop to replenish low inventories.

Informa lowered its estimate for the soybean harvest to 2.890 billion bushels from 3.012 billion bushels, traders said. It pegged the average yield at 38.5 bushels an acre, compared to its early-July estimate of 40 bushels per acre.

By contrast, the U.S. Department of Agriculture in July estimated the U.S. corn crop at 12.970 billion bushels, using a 146 bushel-an-acre yield, and soybean output at 3.050 billion, using a 40.5 bushel-an-acre yield. The USDA is scheduled to release updated figures Aug. 10.

Write to Andrew Johnson Jr. at andrew.johnsonjr@dowjones.com

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(END) Dow Jones Newswires

July 27, 2012 12:09 ET (16:09 GMT)