Almost 100 jobs are being shed in the North by aircraft manufacturer Bombardier.
Managers and professional support staff will be affected, a company statement said.
The redundancies are not related to the firm's trade dispute in the US but centre on the outsourcing of IT services, union leaders added.
A statement from the multinational corporate giant said: "Following the 7,500 global workforce reductions announced by Bombardier Inc. last October, we have reviewed our manpower requirements in Belfast and regret to confirm that we must reduce our workforce levels by up to 95.
"We acknowledge the impact this will have on our workforce and their families and will explore opportunities to help mitigate the number of compulsory redundancies.
"However, we need to continue to cut costs and improve the efficiency of our operations to help ensure our long-term competitiveness."
Last year, Canadian-based Bombardier said it was cutting 1,000 jobs in the North, around a fifth of its workforce there.
Davy Thompson, Unite union's regional officer, said he was disappointed.
"This is another blow to the Bombardier workforce in Belfast and comes in the wake of wider concerns over the ongoing trade dispute with Boeing.
"The rationale offered by management is that this has been brought about by the outsourcing of IT and the need to reduce staff in functional areas.
"We do not agree with their case and we are calling on them to lift the threat of redundancies at this time."
DUP East Belfast MP Gavin Robinson's constituency includes the bulk of Bombardier's operations in Northern Ireland.
He said: "Whilst these jobs are part of the previously announced redundancies, the final announcement is still a huge blow, not least for those families who will be directly impacted.
"This announcement is not directly linked to the ongoing dispute with Boeing and the upcoming ruling by the US Department of Commerce.
"However, it once again underscores the importance of Bombardier to the local economy and the importance of the C Series to Bombardier's operation here.
"We will continue to do anything possible to assist the company as they seek new markets for the C Series which is one of the most innovative aircraft being produced by any company across the globe."
Bombardier, which employs almost 5,000 people in Belfast and accounts for 10% of the region's manufacturing exports, is facing significant costs in the fallout with US aeronautics powerhouse Boeing.
The dispute centres over Boeing's allegations that Bombardier received subsidies allowing it to sell its C Series planes at below-market prices.
The US Department of Commerce is expected to announce a decision on whether to impose duties against Bombardier on September 25.