Chicago wheat rose on Monday on bargain-buying after prices dropped more than 6% on Friday to three-year lows after a larger-than-expected U.S. wheat harvest was forecast.

Corn was pulled up by wheat, while soybeans fell after estimates of U.S. stocks came in above expectations.

Chicago Board of Trade most-active wheat was up 0.9% at $5.46-3/4 a bushel at 1058 GMT, after on Friday hitting a 3-year low of $5.40 a bushel.

Soybeans fell 0.5% to $12.68-1/4 a bushel, and corn rose 0.4% to $4.79 a bushel.

The U.S. Department of Agriculture (USDA) on Friday surprised markets by estimating the now completed U.S. wheat harvest at 1.812 billion bushels, above the average 1.729 billion bushels forecast by analysts in a Reuters poll.

The USDA said U.S. soybean stocks were larger than analysts expected.

"Wheat and corn are being underpinned today by bargain-buying after the sharp falls following the USDA report," said Matt Ammermann, StoneX commodity risk manager. "Soybeans continue to be weakened by the impact of the USDA estimates."

"The wider question is whether the fall in U.S. prices will make U.S. wheat more competitive in export markets, especially against competition from Russia and elsewhere in the Black Sea."

Five more ships are on their way to Ukrainian sea ports using a new corridor opened to resume predominantly agricultural exports, an alternative arrangement to the Black Sea grain deal blocked by Russia.

"The question remains how the export volumes in this channel can be scaled up in the absence of a safety guarantee for the ships from Russia," Ammermann said.

Dealers were also assessing the impact of low water on the Mississippi River, heavily used for U.S. corn and soybean exports.

(Reporting by Michael Hogan in Hamburg, additional reporting by Naveen Thukral; Editing by Rashmi Aich, Eileen Soreng and Jan Harvey)