Undated (AP) _ At least a dozen oil refineries were forced to close or cut back production, temporarily eliminating about 15 percent of the nation's daily refining capacity, as Hurricane Andrew blew into the Louisiana coast.

Many of the refineries began the two- or three-day process of restarting Wednesday. But large stockpiles of oil, gasoline and heating oil should prevent shortages from developing, industry officials said.

No injuries or significant damage was reported at the refineries.

The Texas and Louisiana coasts hold the largest concentration of refineries in the country, handling about 40 percent of the nation's crude oil.

U.S refineries are able to refine 15.6 million 42-gallon barrels of oil per day, but lost at least 2.1 million barrels of capacity because of Andrew, according to interviews with company officials and statistics provided by the American Petroleum Institute.

Many oil companies on Tuesday shuttered their refineries, which are built to withstand hurricane-force winds, as a precaution. Others had to close Wednesday morning when power from local utilities was lost. Marathon Oil Co. cut back on production at its Texas City, Texas, refinery because the storm delayed tankers bringing crude oil to the facility.

A power outage threatened to prolong the closure of one of the country's biggest refineries - Exxon's plant in Baton Rouge, La. - helping push gasoline and heating oil futures prices higher on the New York Mercantile Exchange Wednesday.

The price of unleaded gasoline for current delivery in the futures market rose 0.09 cent per gallon to 62.22 cents. More distant delivery months rose more. Heating oil for current delivery fell 0.11 cent per gallon to 58.12 cents, but contracts for winter delivery rose.

As Andrew looked like it might turn to the west, many companies closed refineries in Texas, including large complexes in the Port Arthur area near the Louisiana border.

''There was some uncertainty where it would hit,'' said Joel Wenger, spokesman for British Petroleum. ''It takes a while to bring a refinery down and you don't want to be caught'' unprepared.

BP closed its 232,000 barrel per day Belle Chasse, La., plant Tuesday and evacuated about 400 workers. Chevron evacuated and shut its 200,000 barrel per day refinery in Port Arthur on Tuesday as a precaution against the oncoming storm.

Andrew started skipping westward along Louisiana's coast late Tuesday night and its winds diminished from 140 mph as it lingered over land. The storm's center came ashore 55 miles south-southeast of Lafayette about 2 a.m. CDT. Early Wednesday afternoon, Andrew was downgraded to a tropical storm when its sustained wind speed fell below 74 mph.

Exxon's Baton Rouge plant, which has a capacity to refine 421,000 barrels of crude oil per day, shut down when it lost power. Exxon was not certain when it would be able to restore operations at the Baton Rouge refinery, spokesman Edward Burwell said.

Several companies Wednesday began restarting plants knocked out by the storm. Restarts can take several days as units that perform various steps in the refining process are gradually brought up to capacity.

Oil rigs in the Gulf of Mexico had been evacuated Sunday and Monday as the hurricane blew across southern Florida, losing little of its force. Oil company officials said Wednesday that winds in the Gulf were still too strong to send aircraft to inspect the off-shore platforms.

Off-shore rigs typically have valves at the sea floor that are turned off to prevent oil from gushing into the water if the platform is toppled, industry officials said.