MELBOURNE, Feb 15 (Reuters) - Origin Energy warned on Tuesday it will book a A$1.89 billion ($1.45 billion) charge in its half-year results, mostly against the value of its stake in the Australia Pacific liquefied natural gas (APLNG) project.
At the same time it tweaked up its forecast for underlying earnings before interest, tax, depreciation and amortisation (EBITDA), raising the bottom end to A$2.45 billion but keeping the high end of the forecast range at A$2.62 billion.
It had previously forecast a 45-60 percent increase in underlying EBITDA from continuing operations for the year to June 2017, which implied a range of A$2.37 billion to A$2.62 billion.
Origin's shares jumped as much as 2.3 percent to a 17-month high following the announcement, outpacing a 0.8 percent gain in the broader market.
APLNG, operated by ConocoPhillips, was not immediately available to comment on the full impairment on the project in Queensland, one of three coal seam gas-to-LNG plants which opened over the past two years amid a sharp slump in global oil and gas prices.
Origin has a 37.5 percent stake in the project.
$1 = 1.3034 Australian dollars Reporting by Sonali Paul; Editing by Richard Pullin