Van Elle, a geotechnical engineering contractor, grew its revenue by 22.1% to £52.6m in the six months ended 31 October 2017, but warned the collapse of Carillion will impact its ability to achieve its previous expectations for the full year.
Underlying profit before tax rose by 15.4% to £5.4m in the first half, while underlying EBITDA increased by 18.7% to £8.4m.
But Jon Fenton, chief executive, warned that the recent collapse of Carillion will have an impact on the business.
Van Elle carried out regular work for Carillion as a specialist lead sub-contractor, principally in respect of rail improvement and maintenance work.
Its outstanding debt and work-in-progress exposure with Carillion is approximately £1.6m.
It has also identified approximately £2.5m of anticipated revenue for the second half of the current year which related to work with Carillion.
"Whilst the group is continuing to engage with the Official Receiver in respect of this outstanding balance, it is now expected that we may recognise an exceptional bad debt charge of approximately £1.6m in its full year results. All of this debt arose after 31 October 2017.
"We have also had constructive dialogue with both the Official Receiver and Network Rail in respect of the £2.5m of anticipated revenue and whilst it is possible that some of the anticipated contracts may be delivered in the current year, the status and timing of specific programmes remains uncertain.
"Van Elle would typically expect to achieve good margins on rail-related work and therefore these anticipated contracts are material in the context of the group's financial results.
"The board believes it is prudent at this stage to recognise that the disruption to the expected order book due to the situation at Carillion will impact the group's ability to achieve its previous expectations for the year as a whole."
At 8:28am: (LON:VANL) Van Elle Holdings Plc share price was -2p at 86.5p