Abbott is seeking 180 voluntary redundancies at one of its production facilities in Sligo.
The move follows the company’s decision to streamline its global nutrition business, putting a greater focus on science based nutritional products.
Abbott's facility at Ballytivnan currently employs over 300 people in the production of feeding sets for these nutritional products.
However, the streamlining of the global operation will mean that these products will no longer be produced for the US market.
The Sligo plant will continue to produce the feeding devices for other international markets.
Staff at the plant were told of the news this afternoon.
Abbott has three manufacturing plants in Sligo and earlier this year announced an investment of €85m in its site on the Manorhamilton road, where 175 highly-skilled employees are to be taken on.
This investment is not affected by today's announcement.
SIPTU Organiser Frank Jones said there was no expectation among their members that such an announcement was imminent.
He said the "sheer number of proposed job losses has shocked the workers who have given loyal and dedicated service to Abbott over many years".
Union representatives will meet tomorrow to discuss the situation with the hope of saving some jobs.