An electric battery “gigafactory” which had been planned for Wales will instead be built in the north of England.
Britishvolt signed a memorandum of understanding (MOU) with the Welsh Government in July to build the plant in St Athan, Vale of Glamorgan.
However, the 3,000-job factory will be built in Blyth, Northumberland, after Britishvolt said it would not invest in Wales earlier this month.
The Welsh Government said the news was disappointing.
It also comes just days after a decision from Ineos that it will build its 4×4 vehicle in France, rather than Bridgend, just 13 miles away from St Athan.
The plant will provide 3,000 skilled jobs and 5,000 more supplying it, and will make batteries for electric vehicles.
The St Athan site had been earmarked due to its proximity to the Aston Martin plant, its programme for the Rapide E – an electric-only vehicle – has been delayed.
Britishvolt’s chief executive, Orral Nadjar, said: “This is a tremendous moment both for Britishvolt and UK industry.
“Blyth meets all of our exacting requirements and could be tailor made.
“It is on the doorstep of major transport links, easily accessible renewable energy and the opportunity for a co-located supply chain, meets our target to make our gigaplant the world’s cleanest and greenest battery facility.”
The Welsh Government said it was disappointed but hoped there would still be potential for a joint-venture in the future.
It said: “We have been working closely with Britishvolt for several months to explore and assist their plans for the establishment of a gigaplant at Bro Tathan.
“Given the ambitious timescales that the company is working to, it has been mutually agreed that Bro Tathan will not be the site of Britishvolt’s first gigaplant.”