The upgrade by Jefferies & Co analyst Peter Misek pushed RIM's share price into double digits for the first time in five months, with the stock up more than 3 percent at $10.04 in early trading on the Nasdaq.

Misek based his more optimistic view of the BB10 launch, set for January 30, on a favorable reaction by telecom carriers to the devices and the new operating system that powers them.

"Preliminary results from our quarterly handset survey indicate developed market carriers have a much more positive view of BB10 than we expected," Misek said in a note to clients.

Shares of Waterloo, Ontario-based RIM, a one-time leader in the smartphone industry, have plummeted in recent years as its aging line-up of devices lost ground to faster and snazzier devices from rivals. The company has bet its future on the new BB10.

RIM hopes BB10 smartphones will help claw back market share it has lost in recent years to Apple Inc's iPhone and devices that run on Google Inc's Android operating system.

Misek, who doubled his price target on shares of RIM to $10 from $5, also raised his rating on the stock to "hold" from "underperform".

"With greater carrier shelf space and marketing support, we now believe BB10 has a 20 percent to 30 percent probability of success," said Misek, who has long been skeptical of RIM's odds of engineering a turnaround.

Misek cautioned that there is still downside if RIM's gamble on BB10 fails, but he noted that the stock could be worth as much as $43 within the next 12 months if RIM's bet pays off and its new operating system gets licensed by other handset makers.

RIM says its new devices will be faster and smoother and have a large catalog of applications, which are now critical to the success of any new line of smartphones. While feedback from both developers and carriers on the new devices has been largely upbeat, financial analysts have been much more circumspect about the company's prospects.

Misek's view is not shared by at least one of his counterparts.

In a note to clients on Monday, Pacific Crest analyst James Faucette reiterated his "underperform" rating on RIM's shares. He said regardless of its quality, there is almost no chance that BB10 will meaningfully change RIM's trajectory.

RIM shares were up 3.7 percent at $9.95 at midmorning on the Nasdaq, while its Toronto-listed shares rose 3.1 percent to C$9.89.

(Reporting by Euan Rocha; Editing by Jeffrey Benkoe; and Peter Galloway)

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