Diesel prices rose again this week for the eighth week in a row, to a national average of $3.43 per gallon, according to weekly figures from the U.S. Department of Energy. That's the highest level since Oct. 27, 2008.

The national average is 21 percent - 59.7 cents - higher than it was a year ago

The highest average price reported by the DOE's Energy Information Administration were in the New England region, at $3.609. The lowest were in the Gulf Coast region at $3.382.

The EIA also reported that the price of regular grade gasoline rose 0.6 cents to $3.110 per gallon, another two-year high. The price of gasoline is 15 percent or 40.5 cents more expensive than a year ago. Diesel costs 24.4 cents more than gasoline.

However, crude oil futures prices finished at their lowest price in more than a month Monday on the New York Mercantile Exchange. According to published reports, the drop was likely due to remarks by Saudi Arabia's oil minister that he expects prices to remain unchanged from last year. The remark led to conjecture that the world's largest crude exporter could increase production and therefore increase supply.

Ali Naimi's comments coincide with growing fears that the global economic recovery could be undermined by rising energy prices, noted Dow Jones news service.