Updated

The maker of the BlackBerry Wednesday gained some ground as it fights a battle over patents with NTP, which is trying to shut down most sales and service of the portable e-mail device in the United States.

The U.S. Patent and Trademark Office issued a final rejection of one of five disputed patents owned by NTP, another step in a long process that Research In Motion Ltd. (RIMM) hopes will allow it to keep operating its U.S. BlackBerry service.

NTP, a closely held patent holding company, has successfully sued RIM for infringement of its patents.

On Friday, the presiding judge in the case, U.S. District Court Judge James Spencer, will hold a hearing to consider NTP's request to go forward with an injunction that would shut down most sales of RIM's BlackBerry wireless e-mail device and service in the United States.

While the lawsuit has worked its way through the court system, the U.S. patent office began re-examining the validity of NTP's patents.

On Wednesday, the patent office issued a notice of its rejection.

RIM said later in the day that the latest decision and previous rejections have been based on "multiple grounds" and "are expected to withstand all future appeals" by NTP.

The patent office's action marked the first "final" rejection of one of the patents at issue in the case, although the agency previously had issued "non-final" rejections of all five of the patents.

NTP has said it plans to see the full reexamination process through, which could take years, because it has the ability to appeal the decisions through the courts.

RIM shares closed down $1.01, or 1.4 percent, at $73.14 on Nasdaq.