3Com confirmed this morning that it is to shut its manufacturing facility in Blanchardstown with the loss of 650 jobs.
The company which provides voice and data networking products, services and solutions for the information technology sector - said they were outsourcing all manufacturing operations as part of a cost-cutting programme, a move affecting 1,000 jobs worldwide.
The Dublin facility will close by the end of next February.
Speculation has been mounting since last week about the future of the plant in west Dublin. Like many firms buffeted by the downturn in technology spending 3Com has sharply cut costs and has sought to outsource work to lower cost centres in Far East.
In the past three years, the company has cut its workforce from more than 10,000 to 3,400 at the end of last May. In June, it said another 10 per cent of jobs.
Blanchardstown was 3Com's last surviving manufacturing operation, the company having already closed plants in Singapore and its home base of California.
The company has suffered 17 straight quarters of diminishing sales as demand for its switches and routers declines and competition from market leader Cisco increases.
At its peak, the Blanchardstown plant, which opened in 1990, employed about 1,000. It has received more than €17 million in funding from IDA Ireland, some of which may now have to be returned.
The Tánaiste Ms Harney expressed her disappointment at 3Com's decision to close the Blanchardstown plant saying the closur will come as "a great blow to both the workers, their families and indeed the wider community."
Offering some hope for the 3Com workers, Ms Harney said she was confident that many of the workers would find alternative employment as a number of enterprises have opened in the west Dublin region.