Pharmaceutical firm Pfizer is to cut 785 jobs at its Irish operations as it prepares to shed 6,000 jobs worldwide over the next five years.
Some 275 jobs will go at Newbridge, Co Kildare; 210 in Dún Laoghaire, Co Dublin; 225 at Loughbeg, Ringaskiddy, Co Cork and 75 at Shanbally, Co Cork.
Employees were told of the plans this afternoon.
Pfizer employs about 5,000 people across 13 locations in Cork, Dublin, Kildare, Limerick, and Sligo. The pharmaceutical company completed a $67 billion purchase of Wyeth in October.
The reductions are part of a drive to increase manufacturing efficiency and lower costs through more effective use of resources and technology, improve plant processes and eliminate excess capacity.
Tánaiste Mary Coughlan said the IDA was confident a new company would be found to operate the three plants Pfizer intended to close and that some jobs could be saved.
She said the decision was not related to the Irish economy but a result of overcapacity in the pharmaceutical sector.
Pfizer said it plans to shut manufacturing operations over the next 18 months to five years at Loughbeg, Caguas in Puerto Rico and Rouses Point in the US. The plants currently manufacture tablets and capsules.
Also slated for closure are the plants in Dublin and Puerto Rico that make sterile injectable medicines.
The company will reduce the size of its operations in Newbridge, and a second plant in Illertissen, Germany.
"The restructuring of our global plant network is critical to our efforts to remain competitive so that we can continue to meet patient needs and expand the access and affordability of our medicines," said Pfizer global manufacturing president Nat Ricciardi.
Up to 14 plants in total are marked to cease operations or downsize. Pfizer will also look at facilities that make animal-health products by June, and will evaluate those that make drugs in emerging markets or nutritional products later this year.
"We're not announcing closures, we're announcing exits," Mr Ricciardi said, citing hopes that Pfizer will be able to sell some of the plants to owners that would continue to operate them.
Last year, Pfizer confirmed it would cut 19,000 jobs, about 15 per cent of the 129,500 employees it would have following the merger. This figure is in addition to more than 14,000 positions it has eliminated since 2007.
Minister for Enterprise Batt O'Keeffe has described today's annoucement as "deeply regrettable".
Meanwhile, there is growing concern tonight over the future of up to 85 jobs at Boston Scientific in Galway.
Management at the company, which employs some 2,800 people, have declined to comment on the speculation.
The development comes following the loss of 175 jobs at the plant in Ballybrit in February.
The company employs a further 2,000 at its plants in Cork and Clonmel in Co Tipperary. In recent years the company closed smaller plants at Tullamore, Co Offaly, and Letterkenny, Co Donegal, and moved all manufacturing to Galway.