Fruit of the Loom is to close its Irish operation, moving operations to Morocco from Ireland over the next four years.
The company's operations in Buncrana, Co Donegal, and in Derry will be phased out. At one point the company employed 3,500 people in Ireland.
The Tánaiste Mary Harney has expressed her disappointment at the decision but said it reflected the fact the sector "is no longer competitive, not just in Ireland, but in this part of the world".
"The priority now must be to continue to attract sustainable industry consistent with our recent economic performance," said the Tánaiste.