The bulk of the loss is down to its Cheesegrater office contract in London, but its woes were also compounded by several other problem jobs.

A round of restructuring and refinancing costs incurred from a £45m share placing earlier this year have also hit the firm.

John Dodds, executive chairman, described the last year as the “most challenging in the group’s history.”

He said: “Problems with the contract for 122 Leadenhall Street were the most significant of several issues which adversely impacted the results.”

Severfield Rowen is still battling to complete the steelwork on the skyscraper, which should top out in the next few months.

Once one-off costs were taken into account Dodds said the underlying operating loss amounted to £19.5m on revenue of £318.3m.

The contractor also announced that Ian Cochrane, previously managing director of Fisher Engineering bought six years ago by Severfield, would take over as chief operating officer following the retirement of Peter Emerson.

Dodds also confirmed he would continue to head the company until a new chief executive is found to replace Tom Haughey, who left the firm last year.

Atlas Ward Structures and Fisher Engineering continued to perform profitably throughout the difficult trading environment.

He added the UK order book at £197m remained solid and contained a good mix of London commercial offices, industrial buildings, warehousing, waste to energy and transport projects.

Dodds said: “The group is now putting a very difficult period behind it and is implementing a number of changes aimed at improving operational and financial performance within a reduced group risk profile.”