* Wheat traders take profits as prices fall after 2-day rise

* U.N. chief expected to disclose talks on Ukraine grain exports

* Soybeans, corn also pull back on wheat pressure, profit taking

CHICAGO, May 18 (Reuters) - U.S. wheat futures fell sharply on Wednesday following a report about United Nations efforts to restore Ukraine grain shipments and as forecasts of ample Russian supplies added to the impact on sentiment of expectations high prices will curb demand.

Corn and soybean futures also slid as falling wheat prices led profit-taking, traders said.

U.N. chief Antonio Guterres is expected to publicly disclose on Wednesday that he is in talks with the European Union, Russia, Turkey, Ukraine, and the United States to try to restore Ukraine grain shipments and revive fertilizer exports from Belarus and Russia, U.N. officials said.

Guterres has said the war in Ukraine, which has led to tighter global grains supplies and fueled a surge in prices, will worsen food, energy and economic crises in poor countries.

The most-active wheat contract on the Chicago Board of Trade (CBOT) settled down 46-3/4 cents to $12.30-3/4 a bushel.

The contract extended overnight losses after the head of Russian agriculture consultancy IKAR told a conference in Geneva that Russia's 2022/23 wheat crop may reach 85 million tonnes, and pegged its export potential at 39 million tonnes.

Meanwhile, crop scouts on the first day of an annual three-day wheat tour of Kansas projected an average yield for hard red winter wheat in the northern portion of the drought-hit state at 39.5 bushels per acre, down from 59.2 bushels in 2021.

Concern is also mounting that dry soils across parts of the Great Plains are extending into the Western Corn Belt - generating worries of drought during the growing season, Karl Setzer, commodity risk analyst at Agrivisor, said.

CBOT corn shed 19-1/4 cents to $7.81-1/2 a bushel, while CBOT soybeans settled down 15-1/4 cents at $16.62-3/4 a bushel. (Additional reporting by Gus Trompiz in Geneva; Editing by Louise Heavens, Bernadette Baum, Barbara Lewis and Jonathan Oatis)