NEW YORK (AP) -- Copper prices hit their highest level in five months Wednesday on expectations that demand may pick up after China announced a plan to stimulate private sector growth.

Copper for March delivery rose 3.35 cents to finish at $3.9095 per pound, its highest closing price since mid-September. Other commodities were mixed ahead of a government report on agricultural supply and demand estimates and concerns about the Greek debt crisis.

China, which is the world's second-largest economy, promised it would raise minimum wages by 13 percent a year through 2015 and work to generate 45 million new jobs, among other measures, to help revive the private sector.

Investors speculated that the efforts could increase demand for industrial metals such as copper, which are used in a number of industries including construction, infrastructure and consumer electronics.

Country Hedging LLC analyst Sterling Smith said China's announcement probably will benefit copper prices in the near term, but there will have to be some resolution to Europe's financial problems for the gains to be sustained over a period of time.

In other trading, wheat, corn and soybeans were mixed as investors awaited the U.S. Agriculture Department's latest update on global supplies and demand, which is due Thursday. Many expect the government to cut production of corn and soybeans in Argentina and Brazil, where a drought has affected those crops.

Richard Feltes, a vice president of research at R.J. O'Brien & Associates, said that some of the recent USDA reports have offered surprising changes in monthly estimates, which likely caused traders to be more cautious in Wednesday's session.

In March contracts, wheat fell 1.5 cents to end at $6.6075 per bushel, corn rose 0.25 cent to $6.425 per bushel and soybeans fell 0.5 cent to $12.315 per bushel.

Other commodities were mixed as questions lingered about Greece's ability to resolve its crippling debt crisis without a default. Greece's leaders are trying to agree on new cost-cutting measures that are being demanded by the country's lenders.

Gold for April delivery fell $17.10 to finish at $1,731.30 an ounce, March silver declined 49 cents to $33.704 an ounce, April platinum rose $13.30 to $1,668.10 an ounce and March palladium increased $6.75 to $715.90 an ounce.

Oil prices rose slightly after the Energy Department said U.S. crude supplies increased less than analysts expected last week.

Benchmark oil increased 30 cents to end at $98.71 per barrel on the New York Mercantile Exchange. Heating oil fell 0.14 cent to finish at $3.1895 per gallon, gasoline futures rose 4.77 cents to $2.9752 per gallon and natural gas fell 2.4 cents to $2.448 per 1,000 cubic feet.

Copyright 2012 The AP.