The Lakeland Dairies group has announced that 146 jobs are to go in the north east of the country as a result of a restructuring plan.
In a statement the company blamed volatile markets, driven by the Fischler reforms, as well as competition from New Zealand and Australia and increased energy costs for the redundancies.
It added that cuts were necessary to sustain a "viable dairy industry" in the north-east of Ireland.
From the end of July next year Lakeland will cease milk drying operations at its Lough Egish plant in Co Monaghan. The company also plans to sell branches of its agri-store network in Cavan, Monaghan, Leitrim, Longford, Louth, Meath and Westmeath.
Following the restructuring programme Lakeland estimates savings of approximately €8.5 million a year from 2008 onwards in reduced operational and administrative costs.
Chief Executive Michael Hanley described the restructuring as a "painful process" that was necessary to "improve competitiveness for the future".
"While we very much regret the need for redundancies, we have taken this decision for sound business reasons to ensure commercial competitiveness and to maximise the milk price that we pay farmers in a dairy industry where considerable uncertainty still exists for the future," Mr Hanley added.
Meanwhile, Siptu's Jim Mullery said that the workers were devastated by the news.
Mr Mullery said the economic consequences resulting from the loss of so many jobs "must not be underestimated" and he called on the Minister for Agriculture to finalise arrangements for a support package for the dairy industry to help alleviate the impact of the closures
