Australia's Origin Energy first-half profit up 5 pct

SYDNEY, Feb 20 (Reuters) - Origin Energy Ltd , Australia's biggest energy retailer, reported a 5 percent rise in first-half underlying profit on Thursday, as higher revenue from oil and gas output and New Zealand offset weaker power and gas sales to customers.

Underlying profit rose to A$381 million for the six months ended December from A$362 million a year ago. That compared with an average of three analysts' forecasts at A$387.2 million, according to Thomson Reuters Starmine.

Origin gave no outlook for its full year profit, but warned that heavy competition for power and gas retail customers in the state of New South Wales was continuing to hurt its profit margins at the same time that energy consumption had dropped.

Analysts expect the group's full year profit will rise 3 percent to A$782 million, according to Thomson Reuters I/B/E/S.

Origin said its biggest project, the A$24.7 billion Australia Pacific liquefied natural gas (LNG) project, remains on track to start exporting in mid-2015, within budget.

Its shares have gained 21 percent over the past year, against a 6 percent rise in the broader market. The stock closed at A$14.85 on Wednesday.

(Reporting by Maggie Lu Yueyang and Sonali Paul; Editing by Bernard Orr)

((maggie.luyueyang@thomsonreuters.com)(+61 2 93731819)(Reuters Messaging: maggie.luyueyang.thomsonreuters.com@reuters.net))

Keywords: AUSTRALIA ORIGINENERGY/RESULTS