Updates with settlement prices

By Renee Hickman

CHICAGO, March 25 (Reuters) - Chicago wheat futures eased on Tuesday as the United States announced it had reached agreements with Russia and Ukraine to ensure safe navigation in the Black Sea.

Corn and soybeans also fell as corn planting moved rapidly in the southern U.S. and a large soybean crop was expected in South America, according to analysts.

The most-active wheat contract Wv1 on the Chicago Board of Trade (CBOT) settled down 5 cents at $5.43-1/4 a bushel, having hit its lowest point since March 5.

Soybeans Sv1 ended down 5-1/2 cents to $10.01-3/4 a bushel, having reached their lowest trough since March 12.

Corn Cv1 fell 6-3/4 cents to finish at $4.57-3/4 a bushel.

The U.S. said it has reached separate agreements with Ukraine and Russia for the safety of Black Sea navigation, as well as a ban on attacks by the two countries on each other's energy facilities.

Analysts said the news is considered bearish for wheat futures as it will pave the way for more secure shipping of wheat exports from the two countries.

Improved weather forecasts in crucial growing regions also pressured wheat futures, according to analysts.

In corn, planting is ahead of pace in the southern U.S., said Mike Zuzolo, president of Global Commodity Analytics, weighing on futures prices.

The U.S. Department of Agriculture in a crop report released on Monday said corn seeding was 65% complete in Louisiana, while progress reached 45% in Texas, 14% in Mississippi and 10% in Arkansas.

Soybeans also fell as a large crop was expected in South America and traders monitored developments in U.S. import tariff negotiations, according to analysts.

A wide swath of tariffs are set to go into effect on imports from U.S. trading partners on April 2, including China, Mexico and Canada, and investors are concerned about retaliation against U.S. agricultural exports.

(Reporting by Renee Hickman in Chicago. Additional reporting by Ella Cao and Mei Mei Chu in Beijing and Sybille de La Hamaide in Paris, editing by Deepa Babington)

((renee.hickman@thomsonreuters.com))