More than 300 jobs are to be lost after mining giant Rio Tinto Alcan confirmed it will shut an aluminium smelting plant later this month.
The site at Lynemouth, Northumberland opened in 1972 and employs 515 staff, alongside 111 staff who work at a power station 200 metres away.
Confirming closure plans first announced in November, Rio Tinto said 323 people at the aluminium smelting site will be made redundant in May.
Some operational activity in the smelter's carbon and casting plants will continue this year and the company's ship unloading facility at the Port of Blyth will continue to operate for around 18 months.
A core team of around 60 employees will remain on site beyond the closure to work on decommissioning, remediation and regional economic development.
Talks on the sale of the power station are ongoing but cannot be concluded until regulations for its continued operation independent of the smelter are confirmed.
Rio Tinto, which has blamed the closure on spiralling energy costs, said the decision was taken after a "thorough strategic review" and consultation process with unions and staff members.
Jacynthe Cote, chief executive of Rio Tinto Alcan, said the company was now working with employees to mitigate the impact of redundancy and securing the future development of the Lynemouth site.