The Tiwai Point aluminium smelter has seen a drop in underlying profit as aluminium prices cooled in the second half of the year.
Its owner, Pacific Aluminium Smelters, said the company's underlying profit for the year ended December was $122 million, compared to its $140m profit the year earlier, but well up on the $100m loss reported in 2020.
Record-high aluminium prices had helped the company in the first half of the year, following Russia's invasion of Ukraine and global increases in energy costs, it said.
However, prices dropped significantly in the second half of the year.
Pacific Aluminium Smelters is owned by Australian mining giant Rio Tinto and is the majority owner of the Tiwai Point smelter.
The smelter's chief executive Chris Blenkiron said it was a good result after a challenging environment for aluminium in recent years.
He said cost control would be a "critical focus in 2023".
"We are in a cyclical business, and while 2022's result is pleasing, aluminium prices have come down from their post-invasion highs, while we saw significant increases to our input costs through 2022 from inflationary and supply-chain pressures."
The smelter produced 333,689 tonnes of aluminium in 2022.
It said it also paid $357m to New Zealand suppliers, including $77m to suppliers in Southland.