The US-owned business confirmed it was making compulsory and voluntary redundancies but could not say how many jobs were at risk.
The Belfast Telegraph understands Terex Materials Processing will be seeking to make around 150 roles redundant across all its sites here – except for Terex Global Business Services at Lurgan.
It’s understood 65 jobs are to go in Omagh, and another 65 at its main Dungannon site.
It also has operations in Ballymoney and Campsie, Co Londonderry.
A spokeswoman said: “The redundancies will involve a mix of voluntary and compulsory redundancies, which impact all Northern Ireland sites except for Terex Global Business Services at Lurgan.
“At this stage, we cannot provide comment on number of redundancies as we have just informed our team members and are now entering a consultation period with them.”
The business, which makes materials processing machinery and aerial work platforms, is one of the Northern Ireland manufacturing sector’s most significant businesses, with nearly 2,000 employees.
In a statement on Monday, the company said: “As Terex continues to navigate market fluctuations, we have observed that the extraordinary surge in demand and backlog following the Covid-19 pandemic, which resulted in outstanding performance in 2023, has now stabilised.
"This has led to reduced demand from key global markets. As a consequence, Terex has carefully reassessed its operational needs to align with the current market conditions and ensure viability and competitiveness of the business going forward.
"Several actions have been taken, including non-replacement of job roles and reducing overtime and travel.
