Up to 300 jobs are to be lost at a factory in Lisburn in Co Antrim.
The US-owned company, Sanmina, is moving production to Hungary.
The company makes cabinets for computers and generators.
Sanmina is one of the largest employers in the greater Lisburn area and the job losses, although not wholly unexpected, come as a major blow to the local economy.
Rumours that the company was in financial difficulties and under investigation have persisted since initial job losses were announced in December.
Workers have been placed on 90 days' notice and talks involving the Amicus union are set to begin immediately.
Future production will be moved to the company’s base in Hungary, which has a lower wage cost base than Northern Ireland.
