A social enterprise in Co Londonderry has bought an energy-saving specialist in Manchester.

Workspace said the acquisition of Therm Tech for an undisclosed sum would help it increase its share of the growing energy-saving sector. Therm Tech manufactures heat recovery and recycling systems, as well as industrial heaters and activated carbon technology.

Workspace, which is based in Draperstown, already owns Homeseal, Northern Ireland's biggest home insulation provider, and energy-efficient lighting firm Environment 2000.

Its chief executive Brian Murray said: "Therm Tech Limited is an already well-established business with an established customer base, a strong focus on its customers' needs and an excellent reputation. This acquisition is a perfect fit for our growth strategy as it extends our capabilities and expertise in energy efficiency.

"Finding the right acquisition to complement our existing business has been a top priority for us."

Workspace last year said it hoped to double annual sales from £7.6m in 2010 to £14m in the next four years.