For the first time, activist investor Carl Icahn declared he will not participate in shareholder efforts to shake up BlackBerry developer Research in Motion.

Appearing on CNBC, Icahn said RIM is not on our radar and that he had no current plans to join Toronto's Jaguar Financial, led by activist investor Victor Alboini, to seek a shakeup of the company. Jaguar and allies already hold about 8 percent of RIM shares.

Last month, shares of RIM soared on speculation Icahn was buying into the Waterloo, Ontario wireless handset maker. All I can tell you is that these rumors get out and we don't dignify them, Icahn said.

In 2007, though, Icahn started buying into RIM rival Motorola and mounted a campaign to elect himself and other allies to the board, which partly succeeded. Last year, Motorola split into two companies. Consumer entity Motorola Mobility agreed to be acquired by Google for $12.5 billion while Motorola Solutions, the professional side, continues to be profitable. Icahn remains a major shareholder of both companies.

In the technology sector, Icahn is currently trying to shake up design software developer Mentor Graphics. Last quarter, he ended a campaign to take over Clorox.

Icahn said he will keep trying to shake up Navistar, the truck maker in which he recently took a 10 percent stake.

RIM shares fell more than 6 percent in late trading to $22.48.