The purchases, containing some 300,000 metric tons of the oilseed, were for shipment from U.S. Gulf Coast and Pacific Northwest ports between December and March, they added.

The wave of buying by the world's top soybean importer was welcome news for U.S. farmers as overseas sales of the top U.S. export crop have lagged expectations.

The flurry of soy import deals, some of China's largest from the United States this year, coincided with uneven crop weather that has marred the start of the soy growing season in Brazil, the world's largest soybean supplier.

The U.S. Department of Agriculture (USDA) on Wednesday reported private U.S. soybean sales totaling more than 900,000 metric tons to China and undisclosed destinations via its daily reporting system, confirming a Reuters story from Tuesday.

Benchmark U.S. soybean futures on the Chicago Board of Trade rallied to a two-month high on Wednesday on news of the Chinese demand.

Cash market premiums for soybeans shipped by barge to Gulf Coast terminals and loaded for export gained up to 6 cents a bushel after adding as much as 10 cents the prior day.

(Reporting by Karl Plume in Chicago; Editing by Jamie Freed)

By Karl Plume