Up to 250 jobs are to be lost in Galway city as part of a restructuring by multinational electronics company American Power Conversion (APC).
Some 60 of those jobs may be relocated to the company's base in Castlebar, Co Mayo.
However, much of the manufacturing is to be transferred to other European bases, the Middle East and Africa, the company said.
APC employs some 500 people at its Ballybrit factory in Galway city and just over 100 in Mayo, having opened its European headquarters at the former Digital plant in Galway 12 years ago.
All redundancies will be voluntary, according to the company, which is non-unionised.
It estimates the redundancy programme and restructuring will cost up to €4 million.
The company, which was founded in 1981 in Massachusetts, makes continuous power supply units for the computer industry which safeguard against "crashes" during power failure.
It has also established plants in China, the Philippines and Denmark, and its headquarters is based in West Kingston, Rhode Island, USA.
The firm reported sales of $2 billion last year, and is a Fortune 1000 company.
Its 23,000sq m (250,000sq ft) Galway plant is located in part of the former Digital premises at Ballybrit, where almost 800 jobs were lost in 1994.
Staff were informed of the job cuts at a general meeting addressed by the plant manager yesterday morning, and were addressed by section managers yesterday afternoon.
No time scale was given for the job losses by the company, beyond stating that severance costs would be "recognised in the third quarter" of 2006.
The company said the plan would be completed in the "first quarter" of next year.
In a statement issued from Rhode Island, the company said that it was announcing initiatives to "reduce costs, improve efficiencies and locate operations closer to the customer by streamlining its operations in Ireland".
This would require "consolidation" of its Irish manufacturing operations in Castlebar and redeployment of "certain customer-facing positions" to locations in the Europe, Middle East and Africa region in "closer proximity to customers".
The company said it intended to retain certain sales, information technology, research and development and business support functions in its existing Galway plant.
It said it would begin discussions with its workforce with "the objective of reducing approximately 200 to 250 positions within Ireland, primarily in the manufacturing, operations and customer-support areas".
The president and chief executive officer of APC, Rodger B Dowdell jnr, said that while the decision had been very difficult, it would put the company in a better position, financially and competitively.
