A U.S. appeals court has upheld a ruling that Research in Motion, the maker of BlackBerry pagers, engaged in patent infringement, but it gave the company a chance to reduce a jury award that has grown to more than $100 million with interest.

NTP, a small patent licensing company based in Arlington, Virginia, which sued Research in Motion, said the decision on Tuesday was a victory in its battle to halt some BlackBerry sales.

NTP is "confident it will prevail" on the remaining issues to be decided in the case, a company lawyer, James Wallace, said in a statement. He predicted that Research in Motion would be barred from selling certain BlackBerry pagers and services until all NTP patents expired in 2012.

The ruling puts more pressure on Research in Motion to settle the lawsuit with NTP, said Ronald Schutz, a patent lawyer who represents St. Clair Intellectual Property Consultants, another patent licensing company that successfully sued Canon and Fuji Photo Film.

"A company like RIM would have to take a serious look at putting together a reasonable licensing deal," Schutz, of Robins, Kaplan, Miller & Ciresi in Minneapolis, said. "The motivation for NTP, given that they're not a competitor, is, how do they get a royalty stream from RIM? It's not in a licensing company's interest to shut somebody down with an injunction."

NTP successfully sued Research in Motion in 2002 for patent infringement in a district court in Richmond, Virginia.

In Tuesday's ruling, the three-judge appeals court in Washington ordered the judge in Richmond to reconsider some aspects of the case. The appeals court, in a 59-page opinion, said James Spencer, the Richmond judge, had misinterpreted a term in a patent, and the appeals court ordered a new review of five of NTP's claims.

The new hearings raise the possibility that Research in Motion, which is based in Waterloo, Ontario, can win a reduction in what it must pay NTP. The new hearings will not disturb Spencer's order blocking sales of BlackBerry e-mail pagers and services, NTP said in its statement.

That injunction is vacated pending the next hearing.