Norsk Hydro said it expects a further financial hit in the fourth quarter following gas supply challenges at its alumina refinery in Brazil.

The Norwegian company said in August that it had temporarily cut alumina production at the Alunorte plant by 50% due to gas shortages, with the lower production coupled with buying more expensive gas on the open market resulting in a potential hit of $75 million to $100 million in the third quarter.

The refinery is supplied by Celba, which informed the company at the time of disruptions to natural gas availability. This means Alunorte hasn't received contracted gas deliveries and is currently sourcing gas in the market at spot-based prices.

Norsk Hydro said late Monday that for the fourth quarter it expects a cost impact from the difference between the contract price and spot-based gas prices for Alunorte at between $90 million and $110 million.

Alunorte doesn't expect further interruption to gas supply as a result of the current situation and continues to manage the matter in collaboration with Celba and the relevant authorities, it said.

"The financial impact remains uncertain and is subject to gas prices, contractual developments, and the implementation of a long-term solution."

The company said Alunorte is also seeking legal remedies and other measures to protect its contractual rights and interests under the existing gas supply agreement.

Celba is owned by New Fortress Energy. New Fortress Energy didn't immediately respond to a request for comment.

Alunorte is one of the world's largest alumina refineries outside of China and has a capacity of 6.3 million metric tons a year, according to Norsk Hydro. The company produced 6.1 million tons of alumina in 2025.

Alumina is a substance extracted from bauxite ore that is mainly used as the raw material to smelt aluminum metal.