Wheat prices were soaring yet again Wednesday as anxious buyers scrambled to secure supplies of the grain.

Benchmark wheat contracts were ahead by 3.7% at nearly $8.36 a bushel in recent action, hitting a record level for a most actively traded contract.

"There is panic among international buyers," says Mike Woolverton, a grains economist at Kansas State University. Earlier in the week, India was reportedly buying 795,000 tons of the wheat at a price of $10.45 a bushel, including the cost of delivery, he explains.

"This was kind of an unusual transaction, and so it is driving the market."

In addition, growing conditions in the Southern Hemisphere wheat-producing countries of Argentina and Australia do not look favorable, he says. When combined with the fact that global stocks are now at a 30-year low, buyers are concerned that there won't be enough grain to go around.

As for other agricultural products, cocoa prices were slipping 1% at $1,777 a ton, while coffee was off 0.7% at $1.17 a pound.

Shares of tractor-maker

Deere

(DE) - Get Report

were slipping 0.9% at about $137, and grain processor

Archer-Daniels-Midland

(ADM) - Get Report

was losing 1% at around $33.

Elsewhere, metals prices were falling. Gold contracts were off $2.60 at $688.90 an ounce, and silver was lower by 14 cents at $12.31 an ounce. Copper futures were giving up a penny at $3.30 a pound.

As for the mining patch, Merrill Lynch was busy upgrading a slew of stocks:

Southern Copper

( PCU) went to a neutral rating from sell, while

Century Aluminum

(CENX) - Get Report

,

Alcoa

(AA) - Get Report

and

Alumina

(AWC)

were all lifted to buy from neutral.

Separately, UBS upped its rating on

Steel Dynamics

(STLD) - Get Report

to buy from neutral.