ConocoPhillips said refining margins fell by half in some regions during the July-September period from the second quarter, but margins were largely in line with the year-ago quarter.

The company provided the details in an overview of market and operating conditions for the recently completed third quarter. ConocoPhillips is scheduled to report those results Oct. 24.

Its share price fell $1.43 to $84.04 in afternoon. The stock has traded in a 52-week range of $54.90 to $90.84.

The company said it likely produced the equivalent of 180,000 barrels of oil a day less in the third quarter than it did in the second. The production estimates include ConocoPhillips' Canadian Syncrude operations but not its Russian Lukoil business. It did not provide figures or comparisons to the year-ago quarter.

The company attributed the decline in output to the loss of its Venezuelan assets, unplanned downtime in the United Kingdom and planned downtime in the Timor Sea and Alaska.

Earlier this year, ConocoPhillips refused to sign a deal with Venezuelan officials to keep pumping oil under tougher terms posed by President Hugo Chavez's government. Venezuela took control of the projects; ConocoPhillips has said it continues to negotiate compensatory terms with government authorities.

The market price for oil -- based on the benchmark West Texas Intermediate -- was up nearly $11 a barrel in the quarter from the second quarter, and about $5 a barrel from the year-ago period, ConocoPhillips said in its report, citing figures from Platts, a division of McGraw-Hill Cos.

More recently, oil prices jumped to a record price of $83.90 a barrel. However, margins -- the difference between what refiners pay for oil and what they are paid for the products they make from it -- have tightened in recent months. For instance, while gasoline margins hit a record of $37.40 a barrel in May, they fell to $2.90 a barrel Oct. 1, according to Barclays Capital PLC.

The market price for natural gas in the third quarter was off about $1.40 per million British thermal units from the second quarter and about 40 cents from the third quarter of 2006, ConocoPhillips said.

The oil company noted its actual crude oil and natural gas prices may vary greatly from the price indicators because of quality and other factors.

In a research note, Bank of America analyst Daniel Barcelo reiterated his $84-a-share price target for ConocoPhillips and his neutral rating. He said he expects the current Wall Street forecast for earnings of $2.36 a share in the third quarter to retreat to BOA's current estimate of $2.26 a share.

ConocoPhillips said its debt at the end of the third quarter was likely $21.9 billion, down from the $22.8 billion it reported at the end of the second quarter.

Exxon Mobil Corp. and Chevron Corp. are the first- and second-largest integrated oil companies in the U.S., respectively.

AP Business Writer John Wilen in New York contributed to this story.