CHICAGO, March 7 (Reuters) - Chicago Board of Trade (CBOT) wheat futures ended mostly lower on Thursday with the benchmark contract tumbling to a fresh 3-1/2-year low late in the session after China cancelled a purchase of U.S. wheat and Egypt scrapped an international purchase tender, traders said.

Corn and soybean futures ended higher on short covering ahead of a monthly supply/demand report due Friday from the U.S. Department of Agriculture (USDA). Corn climbed about 2%, its biggest single-day rise since November, and soybeans touched a two-week top. A weaker dollar made U.S. grains more competitive globally.

Corn and soybeans had also hit multi-year lows recently.

"Traders are covering their short positions because they can't push the price any lower," said Dan Norcini, an independent trader. "They have made a lot of money by selling short, and right now they're heading to the sidelines before the (USDA) report."

Wheat fell after the USDA confirmed that exporters cancelled sales of 130,000 tons of U.S. soft red winter wheat to China. Egypt, among the world's biggest wheat importers, also cancelled an international wheat purchase tender.

Beneficial rain moving across the Midwest is helping keep prices low, Mark Schultz, chief market analyst at Northstar Commodity, said.

CBOT May wheat settled down 2-1/2 cents at $5.28-1/2 per bushel after a late-day slide to $5.28, the lowest on a continuous chart of the most-active contract since August 2020. But K.C. hard red winter wheat futures and MGEX spring wheat futures ended higher, with both markets rallying after a two-session slide.

Traders may be selling CBOT May Wheat in favor of buying K.C. hard red winter wheat and MGEX futures, Schultz said.

CBOT May corn finished up 9-1/4 cents, more than 2%, to settle at $4.38 a bushel and May soybeans ended up 18 cents at $11.66-1/4 per bushel after reaching $11.67, the contract's highest since Feb. 22. (Reporting by Heather Schlitz in Chicago; Additional reporting by Gus Trompiz in Paris and Naveen Thukral in Singapore; Editing by Richard Chang and Nia Williams)