Quantum Hosiery in Strabane is to close, according to local MLA Michaela Boyle.
Fourteen people will lose their jobs as a result of the company’s decision to relocate the posts to England.
Quantum took over “Adria,” once Strabane’s largest employers with around 1,000 workers.
Ms Boyle said the closure was “another massive blow” for the town.
The Sinn Fein representative added she was “absolutely devastated” for the workers and their families.
She added: “I know some of the workers personally and I am truly saddened by the news.
“It appears as though this is the final nail in the coffin for the old Adria site as the last workers from Adria go.”
Ms Boyle added it was “now important” that the needs of the workers were paramount as they faced an uncertain future.
Meanwhile, Ms Boyle’s party colleague, MP Pat Doherty, revealed he had written to Quantum asking them to “re-think” the decision.
Mr Doherty said he had requested a meeting with the head of Invest NI to get an update on the Strabane Business Park which remains empty.
He added: “It is vital that we start to benefit from this site by infrastructure being put in place through inward investment, business expansion and most crucially the creation of new jobs.”