A sharp rally in the soyoil market, keyed by strength in palm oil futures, added to the strength in soybeans.
The US Agriculture Department said on Wednesday private exporters reported the sale of 381,000 tonnes of soybeans to China for delivery in the 2016/17 marketing year.
USDA also said exporters reported the sale of 129,000 tonnes of soybeans to unknown destinations, correcting an Aug. 4 announcement that said corn was the commodity sold in the deal.
Analysts were expecting a USDA report on Thursday morning to show that weekly old-crop export sales of soybeans were in a range from 100,000 to 300,000 tonnes and new-crop export sales were between 1.5 million and 1.8 million tonnes.
A week ago, old-crop soybean export sales were 307,957 tonnes. New-crop soybean export sales were 2.792 million tonnes.
Soyoil futures rallied to their highest since April 21. That market has risen for six straight days, gaining 10.1 percent during that time.