Three ongoing problem contracts in London saw Chorus suffer a loss of £9.6m in the year ending May 2015, following a £15.3m loss the year before.

The firm said that these contracts have now been completed or are near 100% completion with full costs incurred.

Directors are now reviewing the fit-out arm’s bidding strategy going forward.

Chorus also is withdrawing from bidding further work while it seeks to recover cash spent to ensure completion of the legacy projects.

In particular the firm is seeking to submit claims at its Buckingham Gate high-end residential project after serious cost overruns.

In the firm’s accounts director Anthony Dowle said: “The company has incurred substantial losses in relation to this project brought about by delays and changes that it considers have not been properly valued or paid. This matter has contributed to the company’s negative results and balance sheet.

“As a result it has had no alternative but to pursue these amounts in accordance with the contract provisions.”

Its high-profile Sea Containers House hotel project, which suffered losses first flagged up last year after an M&E contractor under performed, has opened for business.

But outstanding technical matters have delayed formal completion certificates being issued.

Work on a complex alteration and extension project at Chancery Lane also finished late leading to cost overruns.

Despite both the Byrne Bros (Formwork) concrete arm and building firm Ellmer raising sales and profits, Byrne Group suffered a £4m pre-tax loss, after running up a £12m loss the year before, on turnover down 14% to £299m.

Forward orders for the formwork business look particularly strong with contracts secured and expected set to raise forecast turnover to £170m next year.

Dowle said: “While this has been a challenging year, the group is now in a position of considerable strength with opportunities in the London and south east market that have shown substantial demand for our services.”

Banker AIB increased committed facilities from £18m to £31m three months ago to strengthen liquidity.