Diesel prices have retreated slightly for the first time in a month, while oil prices are on the rise, pushed by higher seasonal demand and hints of stability in the eurozone.

The Department of Energy's weekly average fuel price survey, released on Monday, shows the national average price of a gallon of diesel slipped half a cent from last week's survey. The national average on Monday was $3.887.

Monday's posted average price was diesel's first decline in the three weeks, which had seen a rise of more than 17 cents a gallon. Currently, diesel stands at 77.1 cents higher than it was this week one year ago.

The DOE reports gasoline prices are continuing to trend downward, posting a decline for the third week in a row. Gasoline dropped 2.8 cents from the previous week, and sat Monday at $3.424 per gallon. It is now almost 56 cents a gallon higher than last year at this time.

Oil prices, on the other hand, are trending upward; closing in New York Monday at $95.52. Benchmark crude was up $1.26 from Friday, to its highest New York closing price since July 29.

Prices rose early in the day as political rivals in Greece worked out a power-sharing plan that will be crucial for securing a $179 billion bailout, but economists remain wary. Their attention is now focused on the wobbly economy of Italy, which also faces huge debts and slow growth. Unlike Greece, Italy is considered too large to rescue.

Besides the political developments in Europe, analysts said investors are also paying closer attention to shrinking oil, gasoline and diesel supplies in parts of the U.S.

The U.S. government reported last week that total petroleum stocks are down 62.6% from a year ago and they're 5.6% lower than the five-year average. Supplies are falling as refineries import less oil while shipping more diesel and gasoline overseas. Airlines and shipping companies also are using more fuel than they did last year, and that's pushing prices even higher.

Regional Average Prices

East Coast: 3.875 Last week: -0.011 Last year: +0.761
New England: 3.950 Last week: 0.015 Last year: +0.780
Central Atlantic: 3.997 Last week: 0.003 Last year: +0.772
Lower Atlantic: 3.816 Last week: -0.020 Last year: +0.755
Midwest: 3.863 Last week: -0.003 Last year: +0.761
Gulf Coast: 3.796 Last week: -0.012 Last year: +0.766
Rocky Mountain: 3.978 Last week: +0.019 Last year: +0.779
West Coast: 4.109 Last week: +0.002 Last year: +0.836
California: 4.213 Last week: +0.050 Last year: +0.934