King's Lynn-based specialist filtration company Porvair has added further muscle to its global operation after snapping up an American company.

The $5.5m (£3.22m) swoop for Chand Eisenmann Metallurgical (CEM) will boost cross-selling opportunities and accelerate growth in the USA, the firm said.

The acquisition provides Porvair with CEM's 42 staff and its filtration design and manufacturing facility in Caribou, Maine.

And the Norfolk-based firm said it will expand the plant's manufacturing lines with £1m of fresh investment.

It is the latest step in the firm's drive to bolster its global presence, which has included a £1m investment into its Chinese manufacturing division and major contract at a gasification plant in India.

The EDP Top 100 company revealed that revenues would be up 7pc on the first six months of last year, as it gears up for its interim results published later this month.

It said revenues had been buoyed by a string of new contracts, including a £11.3m deal with the UK government to design and manufacture a nuclear remediation filtration system.

The company previously revealed a 40pc increase in pre-tax profits to £6.3m, up from £1.8m previously announced in its end of year results.

Ben Stocks, chief executive of the group based at the North Lynn Industrial Estate, said: 'CEM is a highly complementary bolt-on acquisition which broadens our product range, geographic spread and materials expertise.

'Its staff, based in Caribou, Maine, are skilled and highly experienced and are warmly welcomed to the group. There are many cross-selling opportunities apparent in this transaction and we plan to invest in the Caribou facility over the next 12 months to accommodate the expected growth.

'Trading in the first half of 2013 has been satisfactory, and the prospects for the second half; supported by our order books, recent large engineering contracts, and the CEM acquisition; are good.'