DOW JONES NEWSWIRES Range Resources Corp. (RRC) swung to a first-quarter loss on mark-to-market derivative losses and higher charges, while adjusted results topped analysts' expectations as higher production offset a decline in realized prices. The natural-gas company, which also produces lesser amounts of natural-gas liquids and crude oil, said average realized gas prices, which include hedging impacts, dropped 8% in the latest period. Last week, the company said production jumped 17% from a year ago and rose 1% from the fourth quarter. Chairman and Chief Executive John Pinkerton said despite the unusually cold weather during the quarter, the company was able to reach the midpoint of its production guidance. Pinkerton said that adjusted for the weather-related downtime, production would have exceeded the high end of Range's guidance. He added the company was "well on track" to reach its production growth target for the year. Range reported a loss of $25 million, or 16 cents a share, compared with a prior-year profit of $77.6 million, or 48 cents a share. Excluding mark-to-market impacts, stock-compensation and other impacts, adjusted earnings rose to 22 cents from 16 cents. Analysts surveyed by Thomson Reuters expected a profit of 19 cents. Total revenue and other income slid 37% to $187.6 million. Shares rose 0.5% to $53.45 in after-hours trading. The stock is up 18% this year through Tuesday's close. --By John Kell, Dow Jones Newswires; 212-416-2480; john.kell@dowjones.com