It says it is re-evaluating its dependence on its plant in Killarney, and has already begun to send work to other Liebherr plants in Germany.
SIPTU represents 300 of the 670 employees at the Killarney plant.
Its members staged a one-day strike at the plant at the end of last month.
In a statement this afternoon, SIPTU described the company’s statement as “extremely unhelpful” and called on management to pay the increase awarded to its members.
The union acknowledged the significant investment made in the Killarney plant by Liebherr and said the workers valued the commitment by its owners to maintain a state-of-the-art production facility there.
However, SIPTU organiser Marie Kearney claimed the plant made â‚¬63m profit between 2009 and 2012, and she called on management to pay the outstanding wage increase.