Grain futures closed mostly higher on the Chicago Board of Trade Thursday with signs of improved demand in the corn market providing broad support. Corn was up 14 1/2 to up 15 1/4, soybeans were up 30 1/2 to up 38, wheat was up 10 1/4 to up 12 1/2 and oats were off 1/2 to off 1 3/4. Weekly corn exports were a sizable step higher than the previous week at 166,700 metric tons. Demand from ethanol producers and feed lots also lent price support to the market. Wheat closed higher in sympathy with corn with support from weekly exports, which were higher than expected. Soybean sales were pegged at 71 percent of the U.S. Department of Agriculture\'s forecast, a sharp jump from the five-year average of 47 percent. Corn: Dec 7.60 3/4 up 15 1/4, Mar 7.59 1/4 up 14 1/2, May 7.54 up 14 3/4, Jly 7.46 1/4 up 14 1/2. Soybeans: Nov 15.45 1/2 up 36 1/4, Jan 15.46 1/4 up 38, Mar 15.19 3/4 up 35 1/2, May 14.75 3/4 up 30 1/2. Wheat: 8.68 1/2 up 12 1/4, Mar 8.80 3/4 up 12, May 8.84 1/4 up 12 1/2, Jly 8.47 up 10 1/4. Oats: Dec 3.94 off 1 3/4, Mar 3.98 off 1/2, May 3.96 1/4 off 1/2, Jly 3.95 3/4 off 1/2.