* Adjusted net profit 532 million euros, up 1.5 percent
* Production down 5 percent, refining margins stable
* Shares up 1.3 percent (Adds CFO and analyst comments)
By Tracy Rucinski
MADRID, May 8 (Reuters) - Spanish oil company Repsol beat forecasts with a 1.5 percent rise in first-quarter net profit on Thursday thanks to stable refining margins and a surprise gain in its North American gas business due to the harsh winter weather there.
High gas volumes at its North American Canaport plant, which Repsol wrote down steeply last year, drove results at its gas and power division, helping a bottom line otherwise hurt by declines in production.
First-quarter recurring net profit adjusted for one time gains and inventory effects rose to 532 million euros ($741 million) from 524 million euros a year ago, comfortably beating an average forecast of 453 million euros in a Reuters poll.
"This is a first quarter phenomenon and will be tough to repeat in future years," UBS said of Canaport in a note to clients.
Shares in Repsol, which have climbed about 5 percent so far this year, were up 1.24 percent at 19.63 euros by 1300 GMT versus an 0.82 percent gain on Spain's blue chip index.
The first-quarter 2013 net profit figure was revised down from what was originally reported to exclude the contribution from liquefied natural gas (LNG) assets sold to Royal Dutch Shell.
The LNG package was supposed to include Canaport but Shell rejected the plant, with analysts saying it was worth little and had been scarcely used during a glut in North American gas supply.
Repsol, Europe's No. 6 integrated oil major with a market capitalisation of 26 billion euros, is the last of its peers to report first-quarter numbers. Royal Dutch Shell and Norways's Statoil also beat forecasts, while France's Total disappointed investors with a profit drop.
Repsol's total output fell 5 percent to 342,000 barrels of oil equivalent per day (BOE/D) in the first quarter from a year ago, dented by stoppages in Libya, where violence and political unrest threatened to thwart production targets.
The company's 2012-2016 strategy saw production growing at an annual rate of 7 percent to reach 500,000 BOE/D in 2016.
Production will still grow by 7 percent this year, excluding Libya, fuelled by output from new projects in Peru, Venezuela, Russia and the United States, Chief Financial Officer Miguel Martinez said on a conference call to discuss results.
Each day of production stoppages in Libya means a 3 million euro hit on earnings before interest, taxes, depreciation and amortisation (EBITDA), he said.
Refining margins, the difference between the wholesale value of the oil products a refinery produces and the value of the crude oil from which they were refined, were stable at $3.90 per barrel from a year ago but down from $4.10 at the end of 2013.
The results follow a stream of corporate news from Repsol, including the creation last week of a new chief executive post and the sale on Wednesday of a remaining 11.86 percent stake in energy firm YPF for $1.3 billion.
They were also released on the same day the company is set to receive Argentine dollar-denominated bonds as part of a $5 billion compensation for the 2012 expropriation of a 51-percent stake in YPF by the south American country.
Repsol continues to look for acquisitions that will boost cash flow and help the company expand its exploration and production business, Martinez said, particularly after the YPF and LNG sales.
The company ended the first quarter with net debt of 4.7 billion euros, down 12 percent from the end of 2013.
$1 = 0.7183 Euros Editing by Fiona Ortiz and Mark Potter