CANBERRA, May 29 (Reuters) - Chicago wheat futures fell on Wednesday as forecasts for rain in parched Russian sowing areas led to investors locking in profits after prices surged to a 10-month high.

Soybean futures also slipped amid ample supply from South America and corn dipped as the U.S. planting weather improved.

FUNDAMENTALS

* The most-active wheat contract on the Chicago Board of Trade (CBOT) was down 1% at $6.93-1/4 a bushel, as of 0039 GMT, after rising to $7.20 on Tuesday, its highest since July.

* CBOT soybeans slipped 0.5% to $12.23-1/4 a bushel and corn was 0.4% lower at $4.60-1/2 a bushel.

* Wheat prices have surged from a 3-1/2-year low of $5.24 a bushel in March, as dry weather conditions and frosts in key wheat-growing regions in Russia's south reduced yield potential.

* Around 1.5 million hectares of Russian crops have been damaged by frosts, the country's Grain Union said, and Russian agricultural consultancies have slashed their forecasts for local wheat harvest by around 10 million metric tons.

* Weather charts, however, suggest that rain this week could reach more of southern Russia than previously expected.

* Ukraine's grain union also slightly reduced its harvest estimates due to dry weather and smaller planted area.

* Analysts currently forecast combined Russian and Ukrainian wheat production at around 100 million tons. If it falls beneath this level, this would significantly impact global wheat trading patterns, said StoneX analyst Arlan Suderman.

* "Ukraine's potential is still relatively good, due to good soil moisture reserves, whereas Russia's crop could also benefit from improved moisture in June, if that were to occur," Suderman said.

* In the United States, meanwhile, the Department of Agriculture (USDA) rated 48% of the nation's winter wheat crop in good-to-excellent condition, down 1% from the previous week and below trade expectations, but still the highest for this time of year since 2021.

* Argentina is on track to start long-awaited corn shipments to China from July, the country's grain export chamber said.

* South African farmers are expected to harvest 19% less maize in the 2023/2024 season, compared with the previous one, the government's Crop Estimates Committee (CEC) said.

MARKETS NEWS

* A global equities gauge fell slightly on Tuesday while U.S. Treasury yields rose to multi-week peaks as investors waited cautiously for inflation data due later in the week with hopes for clues on the outlook for U.S. interest rates.

(Reporting by Peter Hobson; Editing by Sherry Jacob-Phillips)