Tough construction markets have hit revenue at Carillion, but the support services and building group said orders are holding up and it expects to start increasing revenue again this year.Carillion said first-half revenue in construction services other than the Middle East is expected to be lower than in the same period a year ago, as previously announced.The group restructured its UK building division at the end of last year and says it expects the division to be able to increase revenues in the full year.It won first-half orders worth about £500,000 on a road project in Aberdeen and a £75m deal to expand the main stand at Liverpool FC's Anfield stadium.Group first-half revenue is set to be slightly lower than in the same period last year but Carillion said it remained on track to resume revenue growth in the full year as it also continues to target growth in support services and in the Middle East.First-half orders and probable orders worth about £2.7bn are expected to increase the total value of the order book plus probable orders to over £18.5bn at the half year against £18bn a year earlier.The group also expects its line-up of potential work to increase slightly at the half year to around £38bn from £37.5bn beforehand."Overall, the group continues to perform in line with our expectations and remains on track to resume revenue growth in 2014, despite market conditions remaining challenging," Carillion said in a trading update ahead of first half results on August 20th.PW