Caterpillar is cutting 35 jobs in Northern Ireland as part of a restructuring of the business.
The former FG Wilson business is cutting the jobs - which includes agency workers - to "better align its organisational structure", the firm said.
It comes after the firm axed 140 jobs at the end of last year.
The Unite union's Davy Thompson said the losses were yet another blow to Northern Ireland's manufacturing industry.
"This announcement is yet another blow to our manufacturing sector. Caterpillar, formerly FG Wilson, shed 140 jobs at the end of last year," he said.
"In the last year Northern Ireland’s manufacturing base has suffered a series of losses with more than 1,500 job losses in prominent companies such as JTI Gallahers in Ballymena, Bombardier-Shorts and Sirocco.
"Unite has led calls for the Northern Ireland Executive to take action and bring forward a manufacturing strategy to stem the losses and refocus on securing investment and job creation."
In a statement, the firm said:
"Caterpillar today notified its employees that its Electric Power Division will take measures to better align its organisational structure, resulting in a more efficient and competitive business model to better serve our customers.
After evaluating its business, the Electric Power Division will conduct a reduction in force of approximately 100 positions, which includes a combination of approximately 50 salaried and management roles, as well as roughly 50 agency roles.
"The jobs impact will primarily be in the Mossville, Illinois; Griffin, Georgia; and Northern Ireland facilities, and will begin to take effect on June 30.
"Resources will be provided to assist impacted individuals during this transition. We know this is difficult for our employees and their families, but we must take steps to position the company for long-term success."