Fairey, the engineering and electronics group that has spent pounds 160m on a series of acquisitions over the past five years, has made its most expensive purchase yet.

It is paying $126m (pounds 81m) to buy the ultra-violet curing systems division of Fusion, a Nasdaq-quoted company based in Maryland. Founded in 1975, Fusion is one of the largest suppliers of processes where ultra-violet light is used to create photo-sensitive coatings in a wide range of industrial applications. One of its big markets is the optical fibre industry.

The acquisition adds another niche manufacturing business to Fairey, which already sells a variety of electronic products to a wide range of industries from aerospace to electric power.

John Poulter, chief executive, said: "The Fusion UV Systems business represents a further very positive step in the development of the group's position in the supply of proprietary process technology for the improvement of manufacturing efficiency."

Fairey has spent heavily on building up its electronics operations, which from a standing start have become the group's largest and fastest growing division. They were the main driving force behind a 35 per cent increase in sales and 33 per cent profits hike at the former engineering group.

Profits soared from pounds 25.8m to pounds 34.2m in the year to December despite a warning from the company that the general economic climate was deteriorating. Fairey has tried to protect itself from economic slowdown at home by expanding in Asian and American markets.

The acquisition of Fusion's ultra-violet systems business brings into the group an operation that made profits last year of $10m from sales of $51.1m.

Net assets of the US group, which employs just over 300, are about $25m.