By I-Hsien Sherwood (i.sherwood@latinospost.com) | First Posted: Mar 07, 2013 11:29 AM EST

BlackBerry shares are up, after the company's CEO said interest in the new BlackBerry Z10 smartphone was higher than expected.

Analysts also revised sales expectations up, citing steady sales for the first all-touch smartphone featuring the revamped BlackBerry 10 operating system.

"We are receiving a very positive response to BlackBerry 10 from our customers, but it's also been attractive for customers coming from other platforms. We are a little surprised by that," BlackBerry CEO Thorsten Heins said in an interview.

"Operators are supporting us a lot because they want BlackBerry 10 to be an alternative to Samsung and Apple and they've seen it's a real alternative."

BlackBerry is trying to break back into the mobile market, currently dominated by Apple and Samsung. Unlike rival handset manufacturers like HTC and Sony, BlackBerry is not using Google's Android operating system but pioneering an entirely new OS.

The numbers seem to back Heins up.

"With the Z10 launching in additional markets the last weeks of February, we have increased our February quarter BB10 smartphone sell-in estimate from 300K to 800K units," Canaccord Genuity analyst Mike Walkley said this week.

Walkey was initially bullish on Z10 sales, estimating 2 million would be sold. But in February, he drastically slashed that estimate, down to only 300,000. Now it's back up. Walkey is still skeptical that BlackBerry can make a comeback, but since he changes his mind every few weeks, maybe it's best to wait and see.

"Our follow-up surveys have indicated steady but modest sales levels for the Z10," he said. "With new BB10 smartphones launching in the U.S. only in mid-March or later at subsidized prices no better than competing high-end Apple/Samsung smartphones, combined with our expectations for the Galaxy S IV to launch at a similar time frame in the U.S. market, we anticipate BlackBerry will struggle to reclaim high-end smartphone market share."

The BlackBerry Z10 comes to the United States later this month, perhaps as early as Mar. 15 for AT&T customers.