Wheat futures prices soared Thursday to their highest levels in two years after Russia said it would ban grain exports due to a severe drought, a move that heightens concerns about global supplies of the grain and the possible impact on food prices.

September wheat futures at the Chicago board of trade were up the exchange-imposed daily limit of 60 cents at $7.85 3/4 a bushel in late trading, an 8.3 percent rise and the highest level since Aug. 29, 2008. U.S. wheat futures have gained nearly 85 percent from a nine-month low in June on expectations that demand for U.S. wheat will increase. Get the full story »