Wireless email specialist Visto has sued Research in Motion (RIM), claiming the BlackBerry maker has infringed a number of its patents. At the same time, it let another player in the push email market, Intellisync, off the hook.

Visto's action against RIM followed its victory against Seven Networks late last week. An Eastern District of Texas jury judged that Seven had willfully infringed three Visto patents and awarded the plaintiff $3.6m in damages - less than Visto was asking for, but still a big win. The court upheld each of the five claims and three separate patents Visto brought to trial.

Visto currently has lawsuits in motion against Microsoft and Good Technology which it filed in December 2005 and February 2006, respectively. Good and Microsoft are both accused of willfully infringing Visto's US patents 6,085,192, 6,151,606 and 6,708,221. Good also alleged to have violated US patent 5,961,590, also owned by Visto.

Visto has also filed lawsuits against Smartner and Sproqit. According to a Financial Times report, Visto yesterday said it has no plans to file against Nokia-owned Intellisync.

RIM is alleged to have infringed Visto patents 6,023,708, 6,085,192, 6,151,606 and 6,708,221. The company said it believes Visto's patents are invalid and denied infringement in any case.

RIM has only just settled its long-running battle with NTP - which owns a stake in Visto, acquired in December 2005 and accompanied by the provision of Visto with a licence for NTP's technology. RIM agreed to pay NTP $613m for access to the latter's technology, even though NTP's patents may yet be declared invalid by the US Patent and Trademark Office following a number of re-appraisals of their claims. ®