An activist shareholder in Research In Motion said on Tuesday it wants the struggling BlackBerry maker to consider selling itself or spinning off its patent portfolio, sending RIM's share price higher.

Jaguar Financial Corp said it wants the Canadian company's board to wrest power from co-Chief Executives Mike Lazaridis and Jim Balsillie and for up to five of RIM's independent board members to explore options to maximize shareholder value.

RIM shares were up 1.3 percent at midday Tuesday at $30.52 on the Nasdaq and gained 2.3 percent to C$30.26 on the Toronto Stock Exchange. Both markets were down sharply overall.

RIM shares have lost almost half their value since the start of the year.

Our call is for (RIM's board) to take action; no more study, take action. Take action now, before it's too late, Jaguar Chief Executive Vic Alboini said in an interview.

Alboini said Jaguar has talked to a select group of shareholders and received broadly positive feedback for its plan.

We haven't found one who wasn't supportive, he said. We haven't found any opposition.

Jaguar, a Canadian merchant bank that targets underperforming companies, and its supporters hold less than 5 percent of RIM's stock. It said it now intends to contact a broader section of large shareholders. If a consensus emerges, it plans to push RIM directly with demands for action.

Among the options Jaguar wants RIM to consider are a sale or more aggressive licensing of its mobile patents, paying developers to build applications for its smartphones and tablet computer, and an outright sale of the company.

RIM's stock has skidded since February, hurt by a drumbeat of negative news. The company's earnings have missed expectations and it has cut financial forecasts, while it launched PlayBook, its answer to Apple's iPad, to dismal reviews.

The BlackBerry smartphone - once a byword for corporate communication - has also lost some of its luster, particularly in the United States, where its market share has sunk to 22 percent from 39 percent a year ago, according to comScore.

Jaguar bought an undisclosed number of shares in RIM after the Waterloo, Ontario-based company avoided a vote in June on whether its co-CEOs should also remain co-chairmen. The issue was raised by another activist shareholder.

That shrug-off clearly articulated the disconnect between the shareholder base and the board, and it's clear the management team controls this board, Alboini said.

RIM declined to comment immediately on Jaguar's stance.

($1=$0.99 Canadian)

(Reporting by Alastair Sharp; editing by Peter Galloway)