Diesel Average Falls 6 Cents to $2.967

iesel fuel’s average national price fell 6 cents to $2.967, its lowest level since July, the Department of Energy reported Monday.

Gasoline prices continued their downward spiral, falling 11.8 cents to $2.727. The decline is the third in three weeks and puts gasoline’s national average at its lowest level since April.

Year over year, gasoline prices are down 34.2 cents from record highs following damage to Gulf Coast oil platforms and refineries in the wake of Hurricane Katrina.

Diesel’s average fell in all five national regions. In California, which DOE breaks out separately, the nation’s main trucking fuel dropped 2.5 cents to $3.175.

Last Friday, California began mandating the sale of ultra-low-sulfur diesel, making it the first state to do so. (Click here for previous coverage.)

Meanwhile, crude oil futures dropped 58 cents to close at a three-month low of $68.61 a barrel on the New York Mercantile Exchange on news that Iran may be willing to enter negotiations regarding its nuclear program, Bloomberg said.

Worries that the world’s fourth-largest oil producer would refuse to cooperate with United Nations diplomacy efforts regarding uranium enrichment had driven prices up on speculation that the country might retaliate against U.N. sanctions by restricting oil exports, Bloomberg said.

Each week, DOE surveys 350 diesel filling stations to compile a national snapshot average price.