The Ranbaxy pharmaceutical plant in Cashel, Co Tipperary is set to close with the loss of 100 jobs.
Employees at the Cashel plant, which has been in operation for over 30 years on the Cork Road, make and package generic drugs.
The facility is owned by Sun Pharma, the fifth largest drugs producer in the world, which took over Ranbaxy's international operations last year.
Negotiations over the future of the facility had been taking place for a number of months, with the owner looking to sell the plant.
Sun Pharma had previously stated its intention to scale down or divest itself of certain operations worldwide, with the Cashel site earmarked as one of those locations to be either sold or divested.
In a statement Sun Pharma said it decided to cease operations at its Cashel unit as part of an ongoing operations network review.
It added it expects "to cease operations at Cashel by end of current calendar year".
The company said it will move certain laboratory roles to other facilities within Sun Pharma's global operations network.
It will engage with trade unions and employee representatives in the coming months and "at the end of this period, if necessary, the company may proceed with redundancies".
Another major blow for Cashel and County Tipperary. https://t.co/xlkAW92Ddd
— Mattie McGrath TD (@mattiemcgrathtd) March 31, 2016
Co Tipperary Chamber expressed its disappointment with the decision to close the plant, saying it has been a "consistent employer in the local economy for many years".
The Chamber added it is now working with management at the Ranbaxy plant as well as the Co Tipperary Skillnet training division to identify up-skilling opportunities for staff members who are made redundant.
US-based generic drug manufacturer Amneal, which last year set up its own operation in Cashel, is expected to be recruiting new employess in the coming year as it expands production.
The Chamber said it was hopeful the potential new employment will reduce the economic impact on the area.
