AGL Energy has suffered a 62 per cent slide in its full year profit, weighed down by nearly $580 million in writedowns and one-off costs.

The energy provider made a $218 million net profit for the year to June 30, down from $570 million in 2014/15.

The result included $435 million in writedowns to the value of its upstream gas assets and $117 million in costs linked to its acquisition of NSW power generator Macquarie Generation.

Excluding those one-offs, underlying profit was up 12 per cent at $630 million.

Managing director Andy Vesey said the acquisition of Macquarie Generation had helped lift the group’s operating cash flow and offset the impact of the winding back of the carbon tax.

“The Macquarie Generation acquisition, which completed in early September 2014, has been a major driver of the significant improvement in profit and operational cash flow, and more than offset the effect of removal of the carbon tax,” said Vesey.

AGL has previously announced it will look to cut around $200 million from its cost base and reduce capital expenditure by $100 million by 2017.

It is also looking to sell off $1 billion in underperforming assets.

Vesey said the company would also build around $2 billion in renewable energy projects and transition away from coal-fired power.

“AGL has an important role to play in transitioning Australia’s electricity generation industry to a lower carbon future,” he said.

“We are already at the forefront of this change having built approximately $2 billion of renewable generation and committed not to extend the operating life of our coal-fired power stations.”

The company announced a final dividend of 34 cents per share, fully franked, up one cent from a year ago.

AGL shares were up four cents to $16.64 at 1010 AEST on Wednesday.

Meanwhile, Origin Energy has flagged a further $337 million hit to its bottom line due to lower oil prices and changes to its development plans.

The energy retailer and oil and gas producer will reduce the carrying value of three Australian production assets in its accounts for the 2014/15 financial year.

The largest impairment is a $180 million cut on its operations in the Cooper Basin in central Australia, while assets in the Bass and Otway basins off the coasts of Tasmania and Victoria are also affected.

The new charges reflect changes to Origin’s estimated reserves at each site, changed development plans and lower oil prices.

They come after a $53 million cut to the value of its New Zealand assets taken in the first half of the financial year.

There will be no impact on its Australia Pacific LNG project in Queensland, which is expected to be a major driver of Origin’s growth in the coming years.

Origin shares were down 12 cents, or 1.2 per cent, at $10.03 at 1135 AEST.

– AAP