The Standard & Poor’s GSCI Spot Index of 24 raw materials rose 1.1 percent Thursday to settle at 671.84 at 4 p.m. New York time, led by grains and energy.

The UBS Bloomberg CMCI gauge of 26 prices gained 0.8 percent to 1,630.64.

Corn jumped to a three-week high after a government report showed global inventories will drop more than expected as the worst U.S. drought in more than 50 years cuts output by the most since 1996.

Worldwide inventories on Oct. 1 will be 117.27 million metric tons, down from 123.95 million predicted a month ago and 131.54 million estimated this year, the U.S. Department of Agriculture said. Reserves as a percent of consumption will fall to 13.7 percent, the lowest since 1974. Stockpiles in the U.S., the largest grower and exporter, will fall 37 percent to 15.73 million tons from last year.

Corn futures for December delivery rose 5 percent to $7.7325 a bushel on the Chicago Board of Trade. Earlier, the price reached $7.76, the highest for a most-active contract since Sept. 17.

Soybean futures for November delivery climbed 1.7 percent to $15.485 a bushel the biggest gain since Sept. 28.

Wheat futures for December delivery rose 1.9 percent to settle at $8.86, the largest increase since Sept. 28. The price gained for the fourth straight day, the longest rally since late August. The grain has climbed 41 percent since