Wolfson fights Cirrus patents claim

EDINBURGH-based Wolfson Microelectronics, the recently-floated chip designer, has gone on the counter-attack in the Californian courts to quash copying allegations from US rival Cirrus.

In papers lodged with the Californian District Court, Wolfson, which floated at £214m in October, has dismissed legal claims that it had infringed two of Cirrus's patents, claiming they are invalid.

Cirrus's infringement allegations forced Wolfson to delay by several days its planned public share offering, Britain's first technology float for nearly three years.

Wolfson has filed counter claims against Cirrus for 'improperly interfering with its initial public offer on the London Stock Exchange and its customers'.

Jim Reid, Wolfson's chief technical officer, said today the legal tussle could last for two years, but the company is not making any charges in its accounts beyond normal administration provisions.