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ConocoPhillips (COP) warned that third-quarter results will be hurt by continuing weakness in North American natural-gas prices and refining margins, as well as shutdowns for planned maintenance.

Unlike its rivals, Conoco is more exposed to natural gas prices, which have recently rebounded a bid from multiyear lows. Conoco said Friday the average market price was down 67% from a year earlier, when commodities began their slump from record highs.

The company's third-quarter outlook comes as oil explorers and producers continue to cope with falling demand as consumers and industry cut back on consumption. The waning demand has led to a fuel glut, which has pressured the margins for diesel and gasoline.

ConocoPhillips said daily output averaged about 1.78 million barrels of oil equivalent per day in the third quarter, excluding its 20% stake in Russia's Lukoil Holdings (LKOH.RS). That business will add $33 million to the third quarter's results as second-quarter earnings ended higher than Conoco's estimate. The production figures compare with 1.86 million in the prior quarter.

ConocoPhillips also said it expects results from its midstream and chemical operations to improve slightly from the second quarter, but that its refining and marketing operations to be "significantly impacted" by continued low margins.

In recent premarket trading, shares were down 1.7% to $44.74 as stock futures sold off following weaker-than-expected U.S. unemployment data for September.

-By Mike Barris, Dow Jones Newswires; 212-416-2330; mike.barris@dowjones.com