For the six months to 30 September 2008 revenue was £710.8M, up 12% on £633.8M in the same period last year. Operating profit was £48.2m, up 20% on £40.1M last year and operating margin was 6.8%, up 0.5 percentage points on 6.3% last year.
Staff numbers at 30 September were 18,322, up 8% on 16,909 last year.
Work in hand remains good with 87% of full year forecast revenue secured, and the firm has net funds as at 30 September 2008 of £164.5M.
"These are strong results," said chief executive Keith Clarke.
"Whilst we remain attuned to the wider economic situation, the range of our business and its strength in depth gives us continued confidence for the remainder of this year.
"Looking further ahead, our secure position allows us to continue to invest in Carbon Critical Design and our focus on excellence has positioned the Group to respond with confidence to the challenges and opportunities ahead."