The bluetooth chipset market has been thrown into a sudden spin with the filing of a patent-infringement suit in US.
As a leading chip supplier it was inevitable that CSR saw its share price hit as speculation circulated about the potential impact on the Cambridge-based supplier.
The complaint was filed in the US District Court in Seattle by the Washington Research Foundation against mobile phone firms Nokia, Samsung and Panasonic, which is owned by Matsushita.
According to CSR, all three companies named in the suit are its customers. The UK firm said it has taken advice from its attorneys and added: "The suit is without merit in relation to CSR's Bluetooth chips and CSR will defend its products vigorously."
CSR was not named in the suit as it does not directly sell its chips in the US.
According to court papers, the suit refers to research carried out at the University of Washington where researcher Edwin Suominen received four patents for RF receiver technology involving Bluetooth.
The patents were transferred to the non-profit Washington Research Foundation which subsequently licensed the technology to chip supplier Broadcom.