A federal judge has agreed to put off a trial involving Visto's patent-infringement claims against Research In Motion, but limited RIM's ability to cause further delays.

The trial over mobile e-mail provider Visto's lawsuit against RIM had been set to begin next week. Visto sued RIM in 2006 in the U.S. District Court for the Eastern District of Texas, claiming its popular BlackBerry system infringed four Visto patents and asking for a shutdown of RIM's service as well as damages. But on Wednesday, Magistrate Judge Charles Everingham granted a stay of the trial, requested by RIM, because several of the patent claims involved are being re-examined by the U.S. Patent and Trademark Office.

RIM had requested the re-examinations, in which the patent office is studying the validity of certain parts of Visto's patents. But as a condition of the stay, the company can't ask for any more re-examinations, either directly or indirectly, the judge wrote. RIM also won't be allowed to challenge the validity of any of the patents during the trial by bringing up evidence that has already been considered in the re-examinations.

Earlier this week, the patent office validated 21 out of 22 claims in one of those patents, number 7,039,679, which involves technology for synchronizing e-mail between a mobile device and a LAN server.

Mobile e-mail, based on complex sets of technologies and rapidly growing in popularity, has been fertile ground for patent disputes. RIM came to the brink of a service shutdown in 2006 before settling a suit brought by NTP for US$612.5 million. Visto has also aggressively defended its intellectual property, suing competitors including Good Technology, Seven and Microsoft.