(Adds details on refining, oil sands, prices)
NEW YORK, April 8 (Reuters) - Marathon Oil Corp (MRO.N) said on Tuesday it sold about 375,000 barrels of oil equivalent during the first quarter, up 6 percent from the fourth quarter, and said its refining margins in the first quarter would be "slightly negative."
Included in the poor refining margins were $170 million in expenses linked to the busy plant maintenance schedule during the quarter and a derivatives-related loss of $120 million.
The Houston-based company also said it expects its share of the Athabasca oil sands project in Canada to be about 24,000 barrels per day in the quarter, down from its earlier forecast of 30,000 bpd, because of weather-related issues.
Marathon took its stake in the Athabasca project with the purchase of Western Oil Sands Inc last year, and said it expects to take an after-tax loss in the first quarter of $36 million linked to its derivatives positions.
Marathon's average price realized for liquids in the first two months of the quarter rose $4.68 per barrel from the fourth quarter and its average U.S. natural gas price climbed 75 cents per thousand cubic feet. (Reporting by Matt Daily, editing by Mark Porter and Gerald E. McCormick)