For the six months to 30 June 2014, group revenue was up 22% at £788.2m (2013 H1: £644.6m) and operating profit increased 24% to £35.5m (2013 H1: £28.6m). At constant currency, and including acquisitions, group revenue increased by 33%.
A charge of £30m has been taken for a contract dispute. This aside, profit before tax was £32.5m for the first half, up 21% on the same period last year.
The £30m provision relates to a dispute on a UK project completed in 2008. The claims against Keller are the subject of ongoing litigation.
Businesses in the USA and Australia saw particular improvement.
Chief executive Justin Atkinson said that he and the board “remain optimistic about our long-term prospects”.