Suir Engineering, which provides mechanical, electrical and instrumentation engineering services, is to be bought by private equity group Duke Street.
Suir, which employs 1,300 people, is headquartered in Waterford and has an annual turnover of around €300m.
The company said today's deal, which includes investment by the senior management team, will enable it to enhance the services it offers to clients.
Its operations will continue as normal from its main base in Waterford and its other offices in Dublin, Stockholm, Copenhagen and Frankfurt, the company added.
Completion of the deal remains subject to obtaining applicable regulatory approvals, the two companies said.
Duke Street has a strong track record of investing in industrial service companies and over the last 25 years it has invested over €2.5 billion in more than 50 companies.
Michael Kennedy, Managing Director at Suir Engineering, said he believed the partnership with Duke Street would be transformative for it, enabling Suir to grow steadily while continuing to provide the best service possible to its Irish and international clients.
"Together, we will accelerate Suir's growth by investing in people and expanding the business proposition to include more international work in key client sectors such as technology, renewables, and life sciences," he said.
"We believe this will consolidate our position as a leader in the provision of mechanical, electrical and instrumentation engineering services that are expertly delivered by our very experienced team," he added.
Paul Adams, Partner at Duke Street, said Suir's reputation as a provider of innovative engineering solutions on projects across Europe was second to none.
"The company has a highly skilled workforce, an extremely strong safety record and a healthy pipeline of projects across Europe in all of its highly attractive end-sectors. We have been impressed with Suir's growth strategy and we look forward to actively supporting the existing management team in delivering their ambitious plans," Mr Adams added.
