(Adds estimate, CEO comment)
Nov 4 (Reuters) - Marathon Oil Corp, on Wednesday reported a quarterly loss that topped Wall Street expectations, as low commodity prices prompted the a U.S. oil company with operations in Texas and Equatorial Guinea to write down the value of assets.
Marathon, based in Houston, also tweaked its production growth forecast for this year. The company expects total output to grow 7 percent, at the top end of its previous range for growth of 5 percent to 7 percent.
U.S. oil and gas companies, hit hard by a more than 60 percent drop in crude prices from a year ago, have slashed capital spending and slashed the number of rigs drilling to conserve cash.
Even so, operators have been able to lift output through drilling efficiencies and new techniques used to brings wells to production.
"In an environment where we expect oil prices to remain low for a longer period of time, Marathon Oil continues to take strong action to deliver meaningful cost reductions and efficiency gains, while we remain on target to achieve the high end of our original total Company production growth targets," Marathon Oil Chief Executive Lee Tillman said in a statement.
Marathon, which slashed its dividend 76 percent last week, reported a third-quarter loss of $749 million, or $1.11 per share, compared with a year-ago profit of $431 million, or 64 cents per share.
Excluding $611 million in after-tax charges that included asset impairments, Marathon had a per share loss of 20 cents per share. On average, Wall Street analysts had expected a loss of 40 cents, according to Thomson Reuters I/B/E/S.
Total oil and gas output from continuing operations (excluding Libya) averaged 434,000 barrels oil equivalent per day (boed), up 6 percent from the year-earlier period.
Reporting by Anna Driver; Editing by Tom Brown