A gallon of gas is costing 1 cent more today, or $3.07, reflecting a 6-cent increase over the last week, according numbers compiled by AAA.

The average in the five-county Philadelphia area was $3.16, unchanged from Wednesday but still 4 cents more than a week ago.

South Jersey's average was up overnight by 1 cent, to $2.97, marking an advance of 4 cents since a week ago.

The national average for diesel was up 1 cent, to $3.32. The diesel average in Philadelphia as well as Chester, Delco, Bucks and Montgomery Counties remained at $3.54. South Jersey's average maintained at $3.20.

Meanwhile, oil prices were steady above $91 a barrel in Asia after a report showed that U.S. crude supplies unexpectedly rose last week, which suggests that a recovery in demand may have slowed.

Benchmark oil for February delivery rose 19 cents to $91.31 a barrel late afternoon Singapore time in electronic trading on the New York Mercantile Exchange. The contract fell 37 cents to settle at $91.12 on Wednesday.

The American Petroleum Institute said late Wednesday that crude inventories rose 3.1 million barrels last week while analysts surveyed by Platts, the energy information arm of McGraw-Hill Cos., had forecast a drop of 3.2 million barrels.

The crude supply increase was the first in five weeks and just the second in the last nine. Inventories are 4 percent above last year and 9.3 percent higher than the average from 2004 to 2008.

"This should raise concerns about demand levels relative to supply," energy consultant The Schork Report said.

Oil has hovered above $91 this week amid thin year-end trading volume. Global oil markets are closed Friday for the New Year's Day holiday.

In other Nymex trading in January contracts, heating oil added 0.4 cent to $2.53 a gallon and gasoline futures gained 2.0 cents to $2.41 a gallon. February natural gas futures advanced 3.5 cents to $4.32 per 1,000 cubic feet.

In London, Brent crude rose 17 cents to $94.31 a barrel on the ICE Futures exchange.