Powerscreen has not infringed patent law in relation to a case being pursued through the US courts, the Northern Irish engineering company stated yesterday.

Following revelations that a subsidiary of the company, Powerscreen International Distribution, is being sued for $30 million by the Read Corporation in Boston for alleged illegal copying of machine designs, a spokesman said that media speculation had made the issue "into something else". "It is not unusual for companies to be sued by people who think they have their patents," he said. Powerscreen had been aware of the case since October, 1996, and "has been advised by patent attorneys that, in their opinion, no infringement has taken place". The case relates to designs of machines used for separating building materials. The spokesman added that news of the court proceedings were "much more difficult for Powerscreen at this stage" because of the other issues facing the company.

These include an impending report by its auditors, KPMG, an examination of share price movements by the London Stock Exchange, and an examination of irregularities at its subsidiary, Matbro, by the Serious Fraud Squad.