U.S. soybean futures fell more than 2 percent on Thursday, with the benchmark November contract on track for its largest single-day decline since August, on disappointing weekly export sales and improving U.S. harvest weather, analysts said. Corn and wheat followed the weak tone. November soybeans futures were down 20-1/2 cents at $8.65-1/4 per bushel. CBOT December corn was down 3-3/4 cents at $3.70-1/2 a bushel and December wheat was down 4-3/4 cents at $5.12-3/4 a bushel. Soybeans tumbled after the U.S. Department of Agriculture reported export sales of U.S.