BlackBerry shares rose more than 6 percent in early trading on Tuesday after investor Daniel Loeb's Third Point hedge fund disclosed it had bought 10 million shares in the smartphone maker and technology company.

Third Point said late on Friday it now owns a 1.9 percent stake in BlackBerry, making it the No. 5 shareholder in the Waterloo, Ontario-based company, according to Thomson Reuters data.

Shares in BlackBerry rose 6.8 percent to $9.59 on the New York Stock Exchange, while its Toronto-listed shares rose 6 percent to C$10.47.

The hedge fund on occasion has agitated for changes at the companies it has bought into. It bought a 7 percent stake in Sony last year and pushed the Japanese company to spin off its entertainment business. It has also agitated for changes at blue chips such as Dow Chemical Co and Yahoo Inc.

It was not immediately clear whether Third Point will seek changes at BlackBerry, which is attempting to reshape itself under the leadership of new Chief Executive John Chen.

Chen has been working quickly to implement a series of changes at the company, which is seeking to reinvent itself and focus less on its devices segment, and more on its services business.

A spokeswoman for Third Point declined to comment on the stake in BlackBerry. A spokesman for BlackBerry was not immediately available for comment.

BlackBerry also received a boost on Tuesday after FBR & Co raised its rating on shares of the company to "market perform" from "underperform", citing a refreshed management team that appears focused on forging a path to profit.