Costain appears to have ridden out the recession comfortably, with profit and turnover increasing during the six months to 30 June 2010.
Profit before tax was up 19% to £8.2m (H1 2009: £6.9 million), while revenue climbed from £508m to £533m.
The contractor secured over £400m of new work during the period, including highways, water and Crossrail contracts, taking its order book to £2.5bn, roughly the same as a year ago.
Costain has a strong net cash position of £133.9m (June 2009: £119.2m).
The group's Environment division, which focuses on utilities, delivered revenue of £246m, down from the £301m posted a year ago.
The shortfall was more than made up by Infrastructure, which reported a turnover of £224m (H1 2009: £164m).
Energy & Process increased revenue from £42.5m to £62.4m.
Chairman David Allvey, said: "Costain has again delivered a good result for the first half of the year. It is testimony to the Group's strategic focus and leading market positions that, in one of the most testing economic environments, Costain continues to deliver a strong operational and financial performance.
"We are successfully implementing the 'Choosing Costain' strategy, focusing on major customers with spending plans that are underpinned by strategic needs, regulatory commitments or essential maintenance requirements.
“Costain has a proven scale and capability to successfully deliver complex solutions in markets with significant potential including power, waste, rail and nuclear. We will continue to broaden our capability in providing a range of lifecycle solutions to our customers.
"Whilst challenging market conditions are set to continue for the foreseeable future, the Board expects to report continued progress at the year-end in line with its expectations."