CHICAGO: U.S. wheat, corn and soybean futures tumbled on Tuesday, pressured by macroeconomic worries, strong competition for global grain export business and some forecasts for beneficial Midwest rains next month that could bolster production prospects, analysts said.

"The wetter outlook removed the one factor providing stability for the grain and oilseed markets, allowing prices to tumble today," StoneX chief commodities economist Arlan Suderman wrote in a client note.

Equity markets and crude oil futures sagged, adding to bearish sentiments in grains as concerns grow about whether the U.S. Congress will pass the U.S. debt ceiling pact.

Chicago Board of Trade July wheat settled down 25 cents at $5.91 per bushel, after falling to $5.88-3/4, the lowest on a continuous chart of the most-active wheat contract since December 2020.

CBOT July corn fell 10 cents to end at $5.94 a bushel and July soybeans slid 40-3/4 cents to settle at $12.96-1/2 a bushel, dropping below psychological support at the $13-a-bushel mark.

Wheat was pressured by weak export demand for U.S. supplies. Export prices of Russian wheat are softening further in anticipation of a new harvest and amid low demand from global importers, analysts said.

Also, buyers in the United States are believed to have last week purchased about 60,000 tonnes of European Union origin wheat expected to be sourced about half each from Poland and Germany, European traders said, underscoring high prices for domestic U.S. wheat.

Meanwhile, planting of the U.S. 2023 corn and soybean crops is advancing ahead of the normal pace while producers and traders monitor dry conditions in portions of the Midwest.

After the CBOT close, the U.S. Department of Agriculture's (USDA) first corn condition ratings for 2023 pegged 69% of the U.S. crop in good to excellent condition, below an average of analyst expectations for 71% and down from 73% a year ago.

U.S. corn planting is 92% complete, ahead of the five-year average of 84%, and soybean planting is 83% complete, ahead of its five-year average of 65%, the USDA said.

The government has projected supplies of corn and soybeans will rise in the 2023/24 marketing year due to forecasts for record harvests.

Plentiful supplies from Brazil also weighed on prices. Agribusiness consultancy AgRural on Monday raised its estimate of Brazil's total corn crop to 127.4 million tonnes, from 125.1 million tonnes previously.

(Reporting by Julie Ingwersen; additional reporting by Matthew Chye and Naveen Thukral; Editing by Sherry Jacob-Phillips, Shailesh Kuber, Rashmi Aich and Aurora Ellis)