Corn spot basis bids at river terminals in Illinois were steady to lower on Thursday after recent heavy rains caused flooding that hampered barge movement and tempered grain demand from elevators, merchants said. Five miles (8 km) along the Mississippi River near St. Louis remained closed to vessel traffic, halting shipments in the busy port, according to the US Coast Guard.

The National Weather Service forecast the river at St. Louis to crest at 41.2 feet (12.6 m) on Friday. Navigation there may remain halted until early next week, shippers said. Thursday morning's US Department of Agriculture weekly export data showed last week's net US corn export sales totalled 771,563 tonnes for 2016/17 shipment and 24,131 tonnes for 2017/18 - both within the range of trade estimates.

Drier weather forecasts in key growing areas of the Midwest softened Chicago Board of Trade corn futures. Farmers await breaks in the weather to plant crops. Slow farmer sales of soyabeans for the most part underpinned bids for the grain at river elevators. Net old-crop soyabean export sales of 318,532 tonnes were within trade expectations but new-crop sales of 12,757 tonnes were short of estimates, according to Thursday's USDA data.

Copyright Reuters, 2017