Shares in Research In Motion, the Canadian manufacturer of the Blackberry family of wireless e-mail devices, jumped by 9 per cent on Wednesday after the US Patent and Trademark Office issued another favourable ruling in a dispute that could force RIM to shut down its service in the US later this month.

The stock rose $6.08 to $73.61 on trading volume of 18m shares, or more than three times its daily average, after the patent office issued a final rejection of a patent held by NTP, a US-based patent firm.