Bidding for work on Hinkley Point C contributed to a £4.6m pre-tax loss for SSE Contracting in its latest accounts.
The subsidiary of UK power giant SSE said one-off costs related to bidding for work on the nuclear project “impacted the results” for the year to 31 March 2018.
Extra costs were also incurred as a result of the company’s “right-sizing” programme to slim down operations.
The accounts followed a £5m pre-tax loss in SSE Contracting’s previous year.
A spokesman said the business was focused on mechanical and electrical work and the energy sector, where it expected to benefit from future growth plans.
“There are opportunities arising from supporting infrastructure growth agendas and further investment in high-voltage and large-scale projects across the UK,” he said.
“The business has also been through a successful efficiency programme and it will continue to explore new opportunities that complement SSE Group’s core energy portfolio.”
Profitability at SSE Contracting has been falling since its 2015 financial year, when the business made a £79.6m pre-tax profit on revenue of £489.6m.
Two years later, this had turned into a pre-tax loss of £5m on turnover of £330m for the year to 31 March 2017.
Stuart Chaston took over as managing director of the business following those results, joining the company from Carillion Telent.
As well as the slight reduction in its operating loss for its latest full-year, SSE Contracting also saw turnover fall from £330m to £317.9m as key contracts came to an end.
Net assets for the company remained strong at £166m, primarily thanks to a significant amount of trade receivables due to the firm from other SSE companies.
Cash reserves remained low, rising marginally from £100,000 to £500,000.