Some 350 manufacturing jobs are to go in counties Armagh and Antrim.
Teleflex, a medical equipment manufacturer with headquarters in Pennsylvania, is to close its Lurgan operation, Rusch, with the loss of 270 jobs. In Ballymena, Gallaher is lose 80 jobs at its Lisnafillan plant, which makes Benson & Hedges and Silk Cut cigarettes for the Irish and British market. Gallaher is to retain about 770 jobs at the plant.
In both cases, the job losses are being blamed on international restructuring. Teleflex said the planned closure would be completed by the end of the year and was prompted by a global review involving the closure of 20 plants worldwide with implications for 1,600 workers.
The factory has made medical devices, including tracheotomy tubes and catheters, in Lurgan for more than 30 years. Teleflex said the decision to move the jobs to lower-wage-cost plants in Mexico and Malaysia was not a reflection on the Northern Ireland workforce.
The job losses at Rusch are part of global restructuring that will result in about 1,600 job losses worldwide. GMB union spokesman Mr Michael Mulholland criticised the company's handling of the announcement.
"Obviously the reaction of the workforce was one of anger and disappointment, when the management had stated that they wanted to do things right," he said. "The workers do not feel that has been achieved today by the announcement."
Sinn Féin Assembly member Mr John O'Dowd said Lurgan had been shattered by the news.
"The workers are not being paid off,because there is no market for the product but because the plant owners are moving the people of Lurgan's jobs to Mexico and Malaysia, to low-paid jobs," he said. "The workers' loyalty is of no value to the employers - 250 jobs lost due to the desire to maximise profits."
SDLP Assembly member Ms Dolores Kelly said the job losses were a crushing blow.
"Invest Northern Ireland and the British direct rule minister need to look at provincial towns such as Lurgan, which is on its knees at the minute," she said. "Lurgan needs urgent investment, local people need local jobs for all types of skills."
Reorganisation of European operations is also being cited by Gallaher for its decision to cut 80 jobs in Ballymena, and for job losses in Cardiff and the closure of two factories in Austria.
