Sony has been ordered to pay $18.5m in compensation, after US courts found the company guilty of patent infringement.

The court said it found clear and convincing evidence that Sony wilfully infringed on patents covering "wireless local area network apparatus" while manufacturing the PSP, mylo Personal Computer and Network Walkman products.

Agere Systems, an integrated circuit components company, first filed the complaint for infringements against eight patents in 2006. It has since merged with a company called LSI.