Metro Atlanta gas prices have fallen 15 cents a gallon in the past week but remain about a half-dollar above the national average.

That’s according to AtlantaGasPrices.com, which on Monday morning pegged the metro average for regular at $3.93, down from $4.08 one week ago.

The national average is $3.42, according to the Web site.

Availability in metro Atlanta appeared normal Monday in the wake of shortages that followed Hurricanes Gustav and Ike. That kept prices in the region — and especially around metro Atlanta — much higher than elsewhere in the nation.

Meanwhile, oil prices have continued falling off mid-summer peaks.

Crude oil prices fell to an 8-month low of below $90 a barrel on Monday, amid fears that the spreading financial crisis will exacerbate a global economic slowdown and cut demand.

Light, sweet crude for November delivery was down $4.69 to $89.19 a barrel in electronic trading on the New York Mercantile Exchange by late afternoon in Singapore.

Oil prices have tumbled nearly 40 percent since peaking in July.

Oil demand in the world’s richest countries had already begun to slow since May, before the worst of the financial turmoil hit the United States last month.

Investors will be watching to see if the Organization of Petroleum Exporting Countries moves to cut output should prices fall further.

Iranian Oil Minister Gholam Hossien Nozari said Saturday that it would be “unsuitable” for both producers and consumers for oil to dip below $100 a barrel.

He called on fellow OPEC members not to pump too much oil and avoid a drop in prices.

— The Associated Press contributed to this report