TORONTO - Shares of Research In Motion (TSX:RIM) were up sharply Wednesday amid new takeover rumours surrounding the BlackBerry smartphone maker, this time involving U.K.-based telecom giant Vodafone.

At one point, RIM shares gained as much as 15 per cent before settling back and closing up $2.29 or 10.3 per cent at $24.49 on the Toronto Stock Exchange, with 6.5 million shares traded.

The Independent newspaper in London did not cite any sources, but said that "vague rumours" suggest RIM has urged an unidentified investment bank to consider various strategic options for the company.

RIM shares have tumbled in recent months. Investors remain skeptical of its ability to compete against a growing number of competitors, including Apple's iPhone (Nasdaq:AAPL) and devices using Google's Android operating system.

Canadian institutional investor Jaguar Financial said the status quo for RIM is going to change.

"Whether or not the rumours are true, the reality is that change is in the air," said chairman and CEO Vic Alboini of Jaguar, which owns just under five per cent of RIM stock.

Jaguar now has a list of 10 institutional shareholders calling for changes to RIM's board of directors and management structure as well as a strategic options review, Alboini said in an email.

Reports from the investment community have also suggested that activist investor Carl Icahn is buying into the struggling company with plans to make changes or put it up for sale. Icahn hasn't commented on the reports.

Icahn has taken stakes in many big companies -- from Motorola and Lions Gate Entertainment to bleach maker Clorox -- and usually forces them to restructure. Those shares then generally rise and Icahn cashes in.

"Change at RIM will come, the only question is how," Alboini said. "Will it be voluntary by RIM taking the initiative or will it be involuntary by an unsolicited bid by Mr. Icahn, assuming he is a shareholder, or by Jaguar and its supportive shareholders?"

Jaguar and its supportive shareholders are in favour of RIM being acquired, said Alboini, also chairman and CEO of Toronto-based Northern Securities Inc..

But he said Jaguar and the 10-member shareholder group are also in favour of RIM splitting into three companies: a network company, a device company and a patents company.

RIM has come under scrutiny, particularly from analysts, for its slowness in releasing new smartphone models and for weak sales of its PlayBook, a tablet trying to compete with Apple's iPad.

Last month, the Waterloo, Ont.,-based tech firm missed analyst expectations as second-quarter profits fell 58 per cent to US$329 million amid weaker than expected sales of its BlackBerry smartphones and PlayBook tablets.

RIM also booked a charge of $118 million to pay the cost of cutting 2,000 jobs, about 11 per cent of its workforce.

RIM's stock briefly dropped below US$20 in midday on the New York market Tuesday, to its lowest level in nearly six years.

RIM was once worth about $70 billion and has, from time to time, been Canada's most valuable company. Today it has a market value of about $12 billion or so, making it much more attractive as a takeover target.