Pre-tax profit before special items rose to £23m in the six month ended 30 June compared with £16.1m last time on revenue up 40% at £363.5m.

The group's June order book stands at £1.2bn compared with £0.9bn in December, helped by public sector transport framework contracts and international project awards particularly in the wider Middle East region.

"Notwithstanding the wider economic uncertainties, the group is in a strong position, with good momentum in its many varied markets, which we believe will present us with excellent opportunities in the future," said a group statement.