Seven care homes in the north owned by private operator Four Seasons are to close.
The impacted homes are Victoria Park Care Home and Stormont Care Home in Belfast; Antrim Care Home; Garvagh Care Home; Donaghcloney Care Home near Banbridge; Oakridge Care Home in Ballynahinch and Hamilton Court in Armagh.
Four Seasons, the UK's largest private care home company, said the homes were no longer viable. On Monday, the company reported a pre-tax loss of £25.4 million for the third quarter of the year.
A spokesman for Four Seasons Health Care said the decision was "difficult but unavoidable". He cited a number of factors, including a lack of permanent nursing staff.
"The principal reason behind this decision is that each of these homes is operating at a loss and they are no longer viable," he said.
"The fee income that the homes receive is below the cost of the care they are providing and we have effectively been paying a subsidy for them to continue to provide care. We regret that we cannot continue to sustain this position.
"Additionally, the national shortage of nurses means it has been difficult to recruit and retain permanent staff of the right calibre. This leaves the homes reliant on temporary agency nurses in order to maintain staffing levels, that carries a high cost and presents challenges in maintaining the quality of care we expect to provide.
"The well-being of the residents is our priority and the homes will continue to provide care while we allow plenty of time for them and their families to be supported to find suitable alternative placements. We will do everything we can to ensure there is no disruption to their care during this time."
Last month, Four Seasons announced the closure of its Drumragh care home in Omagh.
The company said it welcomed applications for staff to transfer to the company's other homes, subject to suitable vacancies being available.
"We would like to retain as many employees as we can and we expect that most of our nurses and a substantial number of our care staff will be able to transfer," said the spokesman.
He added: "The decision to close any home is not taken lightly, but we have to focus on homes that are capable of operating successfully to deliver high standards of care for the longer term.
"We are committed to providing elderly care in Northern Ireland, where we are by far the leading provider and will have 62 care homes remaining in operation."
Alan Perry, regional officer with the GMB union, expressed concern.
"I have requested an urgent meeting with the company to discuss this situation facing GMB members and residents in these homes," he said.
