UK construction and services giant Kier Group plc has bought infrastructure specialist McNicholas, which has 200 employees and customers including Phoenix Natural Gas in Northern Ireland.
And a spokesman for Kier said it would be business as usual for McNicholas and its office at Mallusk Road in Newtownabbey. It will be part of Kier Integrated Services within the Kier Group.
The company in Mallusk has worked on building gas mains and connecting customers for Phoenix Natural Gas here since 1996.
It also designs and maintains the Phoenix distribution network throughout Northern Ireland.
The Kier spokesman said: "There will be no change in the day-to-day operation of McNicholas and its work with existing clients."
McNicholas, which is based in Hertfordshire and led by Barry McNicholas, specialises in engineering services for sectors such as gas, power, water, renewable energy and rail and has a total of 1,880 employees UK-wide.
Its clients include Virgin Media, Network Rail and UK Power Networks.
As well as its headquarters in Elstree, the firm has offices in Southampton and Glasgow, as well as Mallusk.
Kier said the acquisition would boost its expertise in infrastructure services.
Kier chief executive Haydn Mursell said: "The acquisition of McNicholas builds on Kier's strategy to accelerate growth and hold leading positions in its chosen markets.
"It is a highly complementary addition to our utility services business and enhances our presence in the power, rail and telecoms markets, with its long-standing client relationships.
"We are delighted that Barry and his team will remain with Kier to continue the growth and development of the business."
Mr McNicholas, chief executive of McNicholas, said its work in telecoms over the last 50 years and its general expertise had given it "leading positions in new sectors such as gas, power, rail and civil engineering". He added: "We are excited by the opportunities that joining a larger group gives our teams to expand and grow.
"It also provides our clients access to a broader range of capabilities."
Kier posted record revenue of over £1bn in its construction division as part of its half-year results in March this year.
The business also had an order book of around £9bn, which it said reflected "strong pipeline conversion in regional building and highway services". The firm's underlying operating profit of £56.5m represented "organic" growth of 4%, it said.