BLACKBERRY maker Research In Motion Ltd has moved a step forward in challenging one of the patents at issue in a key infringement case against the company.

The US Patent and Trademark Office has issued a "non-final action" rejecting all the claims supporting one of five key patents in the BlackBerry dispute, according to a document posted on the patent office's website.
The patents being challenged by RIM are at the centre of a long-running legal battle with patent holding company NTP Inc. that could force RIM to settle the case or face a court-ordered shutdown of most US BlackBerry sales and service.
In the November30 document, an examiner said NTP's arguments in defence of one of the patents had been deemed "non-persuasive". The examiner stopped short of a final rejection pending review of a European report.
However, patent attorneys caution that at this stage the patent office findings are only the beginning of a long appeal process that will likely stretch out months or even years.