Mouchel Parkman chief executive Richard Cuthbert said the deal was in line with the group's strategic plans and would provide growth opportunities.

"It opens up new markets for us. By 2012 we will have a business that is two or three times the size of the one we have now. It makes us look less and less like WS Atkins and more like Capita," Cuthbert told Reuters.

Mouchel Parkman bought HBS, which provides finance and administration services as well as building design and facilities management, from private equity firm Terra Firma.

Mouchel Parkman, which bids mainly for contracts with local and central government and regulated industries, said current trading was in line with its expectations and its order book was at a record high of 2.2 billion pounds.

Shares in the group were up 7 per cent on the news.