Pectel slumped into administration on Wednesday morning and was being run by administrators Zolfo Cooper.
But Keltbray swooped in to acquire Pectel's business assets and current contracts for an undisclosed sum.
The Pectel Group, which provides services to the asbestos removal industry, undertakes a wide range of projects.
Pectel will now operate as a division of Keltbray but continue to trade under its own name.
Keltbray bosses have begun making contact with Pectel Group clients and will complete all current contracts, before trying to expand the business.
Keltbray group managing director Brendan Kerr said: “Keltbray has begun a process of change through our investment in the business and in people, and capitalising on opportunities to acquire assets that provide an opening for developing the business in these challenging times
“Our aim is to grow Keltbray to provide a wide-ranging nationwide service.
“We are delighted therefore to secure the immediate future of the Pectel business by retaining the current 250 employees to ensure there is continuity in delivery, and that the transfer of ownership is a seamless one for employees and importantly clients.”