Corn prices closed at their highest levels since the global food crisis of 2008, reflecting tighter supplies that have markets jittery about shortages in the face of growing demand.

Corn started rising earlier this week after the U.S. Department of Agriculture forecast showed reserves of corn at their lowest levels in 15 years. U.S. farmers will have only 675 million bushels of corn on hand by the end of August, which is roughly 5 percent of all corn expected to be used by that time.

The reported shortage has encouraged speculators to bid up long-term prices while encouraging commercial users like ethanol makers to snap up supplies, said John Sanow, analyst with Telvent DTN in Omaha, Neb.

Corn for March delivery rose 8 cents to settle at $7.0650 a bushel

"We're in a demand-driven market with short supplies," Sanow said. "You combine those two things and you can get some pretty pronounced action."

Corn prices are only allowed to rise each day by 30 cents a bushel, and Sanow said he expects prices to top their all-time high of $7.65 within a few trading days.

In other March agriculture contracts, wheat rose 4.25 cents to settle at $8.67 a bushel, and soybeans lost 17 cents to settle at $14.16 a bushel.

In other trading, metals fell as traders showed continued confidence that they could move their money into riskier investments like stocks.

Gold for April delivery fell $2.10 to settle Thursday at $1,360.40 an ounce while March silver fell 9.9 cents to settle at $29.995 an ounce.

In other metals contracts for March, copper fell 0.75 cents to settle at $4.536 a pound and palladium fell $6.20 to $814.70 an ounce. April platinum fell $17.30 to $1,813.50 an ounce.

Oil prices dropped on Friday after Egypt's President Hosni Mubarak handed over power to the military and left Cairo.

Benchmark crude for March delivery fell $1.21 to $85.52 in midday trading on the New York Mercantile Exchange. Traders have been concerned that anti-government protests in Egypt over the past 18 days could spread to other parts of the Middle East and disrupt oil supplies. Now that Mubarak has stepped down, the military says it will oversee a democratic transition to a new government.

Benchmark oil for March delivery fell $1.15 to settle at $85.58 a barrel on the New York Mercantile Exchange.

In other Nymex trading contracts for February, heating oil fell 1.49 cents to settle at $2.6958 per gallon, gasoline futures lost 0.46 cents to $2.4652 per gallon and natural gas for April delivery gave up 7.6 cents to $3.910 per 1,000 cubic feet.