Fifty jobs are to be lost with the closure of the Cemex building materials plant in Naas, Co Kildare.
In a statement released this morning, Cemex said: "The current downturn within the housing sector, combined with a number of competitive pressures, has created an operating climate under which its pipes and tiles site is no longer sustainable. The company has entered a thirty day consultation period with employee representatives.
"The decision follows Cemex's recent disposal of part of its precast concrete product business to Acheson & Glover."
Siptu branch organiser Adrian Kane said the company had asked the union to enter third-party talks but that the plant was likely to close.
"The plant - which has been in existence for 56 years - is still profitable and the market for its concrete pipes is growing, due to an expanding road building programme," said Mr Kane.
"We are convinced that the principal motivation behind management's attempt to close the plant is to realise the value of the site. The plant has been starved of investment over recent years since its takeover by Cemex."
But a spokeswoman for Cemex said: "The level of investment needed to bring the site up to competitors' levels is not sustainable. She could not put a value on the site or say if it was going to be disposed of.
Meanwhile, it also emerged today that Shannon-based Thomson Financial may move its operations abroad with the loss of 80 jobs.
The company said it is "exploring a proposal to consolidate its content operations production processes."
Thomson Financial, an operating unit of The Thomson Corporation, provides integrated information and technology applications in the global financial services industry. The company has been in Shannon since 1987.
Fine Gael's enterprise spokesman Leo Varadkar said in a statement: "Brian Cowen's much-trumpeted strategy for the economy is built on reckless and unsustainable foundations.
"Fine Gael has warned repeatedly that the Government must tackle the rising cost of doing business in Ireland. Fianna Fáil's refusal to address competitiveness has already resulted in the loss of 30,000 manufacturing jobs in the last five years, with another 45,000 jobs in danger."
