Substatial job cuts are anticipated at the US-owned American Power Conversions (APC) plants in Galway and Castlebar, Co Mayo, following last week's announcement that voluntary redundancies were planned.
A company spokeswoman said an "unspecified" number of job cuts were being sought at the two plants.
It is understood that staff are being given individual details of their entitlements this week.
The company employs more than 800 people in Ireland - 650 in Galway, 150 in Castlebar and 40 in Dublin. The company said the job losses were a reaction to the market downturn.
Some 80 temporary staff at the Galway plant were let go before Christmas, but this is the first time that permanent jobs have been affected in Ireland.
Last year, there was a 15 per cent cut in the company's operations internationally.
APC is non-unionised and management would not comment yesterday on any details of the redundancy package on offer.
The company produces uninterrupted power supply units for the computer and telecom industries.
Originally established in Massachusetts in 1981, it grew to multinational status with the growth of the IT/computer sector, and has plants in the US, the Philippines and Denmark as well as in Ireland.
APC took over the old Digital hardware plant at Ballybrit in Galway, following that company's closure in 1993, and became one of the west of Ireland's biggest employers when it also opened in Castlebar.
However, there has been much speculation about its future in recent weeks, since the announcement by Volex of 230 job cuts in Castlebar. Volex also manufactures cable assemblies and power supplies.