The Irish arm of construction and engineering giant Laing O'Rourke went into the red last year as revenues plunged and its workforce was cut by more than half.
Accounts just filed with the Companies Registration Office by Laing O'Rourke Ireland Ltd show that revenues at the company last year dropped by 75.7pc from €103.6m to €25.1m to the end of March 2010.
The figures show the company made a pre-tax loss of €1m after recording a pre-tax profit of €2.8m in 2009.
The losses incurred last year resulted in the company's accumulated losses totalling €6.2m.
According to the directors, they "are disappointed with the loss for the year incurred as a result of difficult economic conditions".
The figures show that numbers employed at the firm more than halved during the year from 590 to 282 -- a loss of 308, or 52pc of its workforce, with site staff bearing the brunt of the job losses with 185 posts shed in that sector.
The job losses resulted in a reduction in staff costs of 45pc from €33.8m to €18.7m.
The firm incurred a €753,000 writedown in the value of investment properties during the year following a €2.8m write-off the previous year.
The company recorded an operating loss of €1.2m compared with an operating profit of €2.5m in 2009.
The Irish operations represent a small fraction of the group's global activities, with Laing O'Rourke being the biggest privately owned construction company in Britain.
The group recorded revenues of £4.3bn (€5bn) in 2010 -- a 15pc drop on 2009.