Cleaning and security firm Robinson Services is to expand its workforce by 300 following the purchase of 180 cleaning contracts from Resource Group.
The deal, thought to be worth over £1m, will bring Robinson Service's total workforce to 1,500 and, it said, makes it the largest private support services business in Northern Ireland.
The deal was financed by Northern Bank.
As a result of the purchase Robinson Services expects turnover to grow by 18% in 2012 after growth of 12% in 2011.
Its clients include Tesco, Henderson Group and Premier Inn.
David Robinson, managing director of Robinson Services, said: "We're convinced that we offer a best-in-class service and this expansion will support us in our ongoing plans for growth and continued export of our expertise across the UK.
"We already have an industry beating 97% retention rate for customers but we're determined to go even further."
Lewis McCallan, senior corporate acquisition manager at Northern Bank, said the business is looking ahead.
"Robinson Services has taken a long-term, strategic approach to its growth strategy," he said.
Robinson Services has grown from being an Antrim-based start-up to become one of the largest employers in Northern Ireland. In 2008, the firm diversified into providing security services.
Wayne Horwood of Horwood -amp; Holmes Corporate Finance, the lead advisor on the acquisition and refinancing, said the sector is performing well.
"The diversity of the support services sector is creating opportunities for well-structured organic and acquisitive growth plans," he said.