Guinness Peat Group reported a first half loss of 36 million pounds ($70m) after taking into account a 110m euro ($174m) fine imposed on its UK unit, Coats, by the European Court.
The loss for the six months to June 30 compared with a profit of 13m pounds ($25m) in the same period in 2011.
The result also took into account interest and provisions made previously, which resulted in an exceptional charge of 76 million pounds ($148 million) to GPG's income Statement.
The European Commission had alleged that Coats - a leading thread and zip maker - had entered into a market sharing agreement in the European haberdashery market from 1977 to 1998. GPG had its appeal against the decision rejected.
"The merits of the court's view are no longer relevant, but the impact is substantial notwithstanding that we had ensured adequate funding was available to meet the worst case," GPG, a former investment company headed up by Sir Ron Brierley, said.