NTP is best-known for ait won against RIM in 2002. It is currently seeking a court injunction to shut down the popular BlackBerry e-mail service in the United States.
NTP already has, another closely held RIM rival, and Nokia, the world's largest mobile phone maker.
The two firms said the latest agreement givesaccess to NTP's patents until they expire. They said NTP had also acquired an equity stake in Visto.
"This license agreement further reinforces the strength and validity of NTP founder Thomas Campana's lifelong work," NTP co-founder Donald Stout said in a statement.
"Additionally, this is a clear win for mobile e-mail users everywhere as it provides them with a viable alternative to RIM that protects them from any NTP litigation risk."
Visto Chief Executive Brian Bogosian said the deal will ensure that his company's technology will be a "viable alternative long after other players have seen their solutions silenced."
Stout told Reuters last week that NTP had rejected an "unacceptable" written offer by RIM to settle their legal battle and that the two sides were not then negotiating.
RIM and NTP announced a $450 million settlement in March, but the deal fell apart in June.
RIM was pushed closer to a possible U.S. shutdown after U.S. District Court Judge James Spencerthere was no "valid and enforceable" settlement agreement with NTP. He also denied RIM's request to stay proceedings pending the completion of a by the U.S. Patent Office.
After reviewing eight NTP patents, the U.S. Patent Office has issued initial rulings rejecting 100 percent of NTP's claims. But NTP has said the full review process could take years because it can appeal the process in court.
RIM is facing growing concerns from customers.
In a report dated December 5, U.S. technology consulting firm Gartner advised clients to put "mission-critical" BlackBerry deployments on hold until RIM's position in its legal battle is clarified. It also said clients should consider alternative offerings.
RIM shares were up 59 U.S. cents at $65.13 on Nasdaq on Wednesday. In Toronto the stock rose 45 Canadian cents to C$74.91.
American Technology Research analyst Rob Sanderson said in a note on Wednesday he still expects a "reasonable resolution" to NTP dispute. He maintained his "buy" rating on RIM stock with a $110 price target.
"The most common "whisper number" on settlement seems to be $1 billion, though we consider this aggressive," the note said.