The slow recovery of areas affected by hurricane Katrina is causing a gradual drop in gas prices across the country.

In Bismarck, the price of gas containing 10 percent ethanol dropped to $2.79 at many stations, which is a 10-cent decrease over Wednesday's prices.

Regular unleaded was $2.84 at many stations and premium was at $2.95. Diesel could be purchased for $2.59 in Bismarck.

Leif Peterson, a spokesman for the Mandan Tesoro Refinery, said the supply of gas has increased because of infrastructure repairs on refineries in areas affected by Katrina and increased imports of oil.

Peterson also noted that consumers have cut back on gas.

"It's a reflection of supply and demand,"Peterson said.

Thursday's drop in price is a continuation of decreases since gas surpassed $3 a gallon after the hurricane clobbered New Orleans and other areas.

According to the Energy Information Administration, after increasing by 45 cents per gallon between Aug. 29 and Sept. 5 following Hurricane Katrina, the average retail gasoline price fell by more than 11 cents between Sept. 5 and Sept. 12.

In a news release, the EIA said refineries are slowly beginning to return to operation and key pipelines began to see gasoline flow more freely, but the supply system is still a long way from being back to normal.

However, gas prices are still about $1.10 above this time last year, according to the EIA.

(Reach reporter Tom Rafferty at 223-8482 or tom.raffertyReach reporter Tom Rafferty at 223-8482 or tom.rafferty@;bismarcktribune.com)@;bismarcktribune.com)