(Updates for market close)

By Heather Schlitz

CHICAGO, Aug 11 (Reuters) - Chicago Board of Trade corn and

soybeans fell on Tuesday as participants adjusted positions

ahead of the widely followed U.S. government crop forecasts on

Wednesday.

Wheat also edged lower, with disruptions to Black Sea

exports already factored into the market and reports of progress

in talks to restore shipping through the Strait of Hormuz also

hampering prices.

The most-active wheat contract on the Chicago Board of

Trade settled 10-1/4 cents lower to $6.30-1/4 per bushel.

Wheat prices had risen earlier, adding to gains from the two

previous sessions, supported by signs that attacks by Ukraine

and Russia on each other's shipping routes were reducing export

flows.

Falling prices in Russia, slow international demand and

efforts by Kyiv and Moscow to use alternative logistics routes

have tempered market reaction to Black Sea tensions.

CBOT soybeans ended 10-1/4 cents lower to $11.68-3/4 per

bushel, while corn ended 1-1/4 cents lower to $4.60-1/2 per

bushel.

Grain markets were turning their attention towards the U.S.

Department of Agriculture's August supply-and-demand report that

will be released on Wednesday, which will include highly

anticipated revisions to the USDA's outlook for this year's U.S.

corn and soybean harvests.

Ahead of the USDA's monthly reports, analysts surveyed by

Reuters on average expected the agency to lower its estimate of

the U.S. 2026 corn yield to 182.4 bushels per acre, from 183.0

previously. Analysts on average expect the USDA to lower its

forecasts of U.S. 2025-26 and 2026-27 soybean ending stocks.

After Monday's close, the USDA trimmed its weekly soybean

condition rating while keeping its corn score steady.

Rain and milder temperatures aided both crops last week

after excessive heat and dryness during July, analysts said.

"It's tough to keep the market strong without consistent

bullish news," said Randy Place, analyst at Hightower Report.

"It's difficult to keep prices up when you have big rains coming

just where producers need it."