Origin Energy's first-half statutory profit is down by $197 million, or 25 per cent, to $599 million, hurt by a dip in LNG prices and weakness in its energy markets business.
However, chief executive Frank Calabria has hailed the energy firm's "robust" operational performance, which helped its free cash flow increase 22 per cent to $680 million.
Underlying profit for the six months to December 31 fell to $528 million from $592 million a year earlier, while underlying earnings fell 8.0 per cent to $15.9 billion.
Mr Calabria said the strong performance from Australia Pacific LNG "more than offset" the impact of price re-regulation, one-off generation outages and lower electricity volumes in energy markets.
Origin's shares were up 11 cents, or 1.4 per cent, to $7.94 at 1446 AEDT after reaching as high as $8.20 in morning trade.
But this positive response, Mr Calabria said, could have also resulted from Origin re-confirming its energy markets earnings of $1.4 billion to $1.5 billion, as well as upgrading its guidance for integrated gas, which is now expected to make a full-year distribution to Origin of $1.1 to $1.3 billion.
"I thought the business overall performed well," he told AAP on Thursday.
"We've got a dynamic energy market so we've got to continue to improve all the time but that was another step for us."
Mr Calabria said the contribution from Australia Pacific LNG and proceeds from the sale of Ironbark - Origin's Queensland-based undeveloped coal seam gas project - as well as good cash conversion in energy markets, had driven strong growth in free cash flow.
He said Origin had also continued to repair its balance sheet, paying down more than $1 billion in debt during the past 12 months.
"We reported record production and an increase in profit in integrated gas on the back of the continued operational strength of Australia Pacific LNG," he told the ASX on Thursday.
Mr Calabria said Origin's generation team worked "against the clock" to repair a damaged unit at Mortlake Power Station in six months, while output at Eraring was lower due to planned and unplanned outages.
"These one-off outages detracted from an otherwise strong operational performance," Mr Calabria said.
"Given the relatively tight supply in the market, our focus was on ensuring that all our generation units were available for the summer peak so that homes and businesses could continue to enjoy reliable supply."
Mr Calabria also confirmed Origin would increase its renewables generation capacity to 25 per cent by the end of the calendar year.
"I do feel that we've made meaningful strides into introducing renewables into the supply of electricity for our business," said.
"We'll continue the transition over time to cleaner energy ... but it's how we do that in a way that actually balances affordability for customers while getting emissions reduction."
Origin declared a fully franked interim dividend of 15 per cents per share, up from 10 cents per share last year.