By The Associated PressPrices for platinum surged Tuesday following a strike at a platinum mine in South Africa. Lonmin, one of the world's largest platinum producers, said workers went on strike briefly at one of its mines, but later returned to work. The mine has been the site of bloody confrontations between police and striking miners in recent months. An estimated 80 percent of the world's platinum reserves are in South Africa. Platinum for April delivery rose $19.50 to settle at $1,585.70 per ounce. Other metals were higher as well. Silver and copper rose with encouraging U.S. economic news and upbeat investors drove the stock market to new highs. Activity in the U.S. service sector expanded in February at the fastest pace in a year. The Institute for Supply Management said its gauge of non-manufacturing activity rose to 56 in February from 55.2 in January. Any reading above 50 signals growth. Silver for May delivery gained 10.8 cents to settle at $28.604 per ounce. May contracts for copper increased 1.35 cents to $3.515 per pound. Palladium for June delivery jumped $20.15, nearly 3 percent, to settle at $734.60 per ounce. Prices for industrial metals like copper often reflect expectations for economic growth. Gold prices inched up. Gold for April delivery added $2.50 to $1,574.90 per ounce. Grain prices also rose slightly. Wheat for May delivery rose 3.5 cents to settle at $7.06 a bushel. Corn for May rose 5.75 cents to $7.09 a bushel, and soybeans for May rose 4.5 cents to $14.665 a bushel. In energy contracts, benchmark crude for April delivery rose 70 cents to finish at $90.82 a barrel on the New York Mercantile Exchange. Oil prices had dropped over the previous three trading days and have sunk more than 6 percent in two weeks. In other energy trading on the Nymex:
â¿¿ Wholesale gasoline added 5 cents to finish at $3.15 a gallon.â¿¿ Heating oil rose 5 cents to end at $2.97 a gallon. â¿¿ Natural gas was flat at $3.53 per 1,000 cubic feet.