In the trading week which ended October 26, the most active contract for December wheat delivery went down 9.5 cents, or 1.85 percent, to 5.1475 dollars per bushel.
November soybeans suffered a 11.75-cent decline, or 1.37 percent, to 8.45 dollars per bushel. Only December corn rose slightly week on week, posting a 0.75-cent gain, or 0.2 percent, to 3.67 dollars per bushel.
CBOT futures were under pressure of drier weather conditions, which enabled U.S. Midwest farmers to speed up harvest of corn and soybean crops delayed by long lasting rainfall.
On Thursday, the U.S. Department of Agriculture (USDA) released its weekly export sales data, showing weaker performance for the period of October 12-18.
U.S. exporters reported a total sale of 212,700 metric tons of soybeans, versus the trade's expectations of between 300,000 and 700,000 metric tons.
Export sales of corn was at 349,500 metric tons, compared to the trade's expectations of between 400,000 and 750,000 metric tons.
Although U.S. exporters sell 442,600 metric tons of wheat, falling within the trade's expectations of between 250,000 and 500,000 metric tons, the sales were still down 7 percent from the previous week and below the prior 4-week average.
This was the second bearish weekly export report in a row, which immediately sent the CBOT prices to new lows.
On the last day of this trading week, bargain hunting and short covering significantly pushed up the prices, but most of the futures still settled in the negative territory week on week, except the corn which managed to close slightly up, less than one cent.
AgResource, a Chicago-based agricultural research firm, said as harvest of soybeans has advanced well across the Midwest, it expects that 64-68 percent of the U.S. crop will have been collected by Sunday evening.
As there is no breakthrough in trade negotiations between the United States and China, tariffs on soybeans are likely to stay in place for the foreseeable future. With world ending stocks and U.S. stocks projected to come in at all-time highs, the soybean futures will remain under heavy pressure, said market watchers.
CBOT wheat prices, which had dropped more than 2 percent on Thursday, rebounded back above the 5 dollar per bushel threshold over the news that U.S. company Cargill on Friday offered Egypt two cargoes of U.S. soft red winter wheat at 219 dollars/metric ton, the cheapest of all wheat offered to Egypt.
Although Egypt might in the end buy Russian or eastern European wheat based on cheaper freight, Cargill's offer is noteworthy because it shows that American wheat is still competitive in international market, said analysts.