There was no let-up in demand for U.S. grains last week amid drought-hit Russia's export ban, as federal government data showed weekly export sales of corn and wheat exceeded trade expectations.

"Corn is the cheapest feed grain and U.S. corn is the cheapest in the world," said grains analyst Don Roose of U.S. Commodities in West Des Moines, Iowa.

He said the corn market was bolstered by expectations of a smaller-than-expected U.S. crop this year and a surge in global demand in the aftermath of Russia's export ban until Dec. 31.

Many analysts believe that the U.S. Department of Agriculture's estimate of an average corn yield of 165 bushels per acre this year was high. A Reuters poll of analysts and traders pegged the yield at 163.7 bushels

The USDA export sales report for the week ended Aug. 19 put old- and new-crop corn sales at 1.7 million tons, topping expectations for up to 1.2 million. But it was below the prior week's 2.9 million

Egypt, a big buyer of wheat from Russia until the export ban, booked 490,400 tons of U.S. corn. Cairo has been an active buyer of U.S. corn in recent weeks.

Japan, the top buyer of U.S. corn, bought 587,800 tons of corn last week. Mexico booked 284,000 tons of new-crop supplies.

Egypt Buys More Wheat
In wheat, export sales totaled 1.1 million tonnes, just above trade expectations for 750,000 to 1 million tons and the third week of sales exceeding 1 million tonnes. Still, the latest tally was down 24 percent from the prior week.

Egypt bought 135,900 tons of wheat, taking its tally in the 2010/11 season (June/May) to 1.1 million tons.

USDA said unspecified buyers bought 246,000 toes of wheat last week.

USDA said sales of old- and new-crop soybeans totaled 991,800 tons, within expectations for 900,000 to 1 million.

It was the first time since the week of July 1 that sales of old- and new-crop supplies dipped below 1 million tons.

Top buyer China booked 289,800 tons of new- and old-crop soy supplies, the smallest net sales to the country since the week of June 10.

Demand for U.S. grains have been on the rise the past month as Russia's worst drought in more than a century forced the No. 3 wheat exporter to ban grain exports through Dec. 31

"They are big numbers but the big surprise is why these didn't show up in the 24 hour reporting system. The 529,000 tonnes (corn) to Japan was impressive and the Egypt business was big," said Terry Reilly, analyst for Citigroup.

The USDA's daily export sales reporting system requires sales of corn, wheat and soybeans totaling 100,000 tonnes or more in a day to be reported to the department by the next business day.

Under this system, exporters had reported to the USDA last week that they had sold 220,000 tonnes of soybeans to China, 110,000 of soybeans to unknown buyers, 240,000 tonnes of corn to Egypt and 121,920 tonnes of corn to Japan. (Reuters)