Shares in Canada's Research In Motion fell on Thursday as the BlackBerry maker's new tablet computer, the PlayBook, received desultory initial reviews.
The Waterloo, Ontario-based RIM saw its share price shed 1.66 percent on Wall Street to $53.92 in a market that finished slightly higher overall.
The PlayBook, which is to hit store shelves on Tuesday, is RIM's answer to Apple's hot-selling iPad and its first foray outside the mobile phone realm.
RIM is offering three models of the PlayBook. A version with 16 gigabytes of storage will cost $499, a 32GB model will sell for $599 and one with 64GB will cost $699. The prices are the same as for comparable models of the iPad.
The PlayBook features Wi-Fi connectivity to the Internet while Apple sells both Wi-Fi and 3G versions of the iPad.
RIM describes the PlayBook as the first "professional-grade" tablet and has stressed its integration with its BlackBerry smartphone, a favorite among many business users.
BlackBerry users can pair their handset with the PlayBook using a Bluetooth connection, a feature called BlackBerry Bridge, to view their email, calendar, contacts or other content.
But David Pogue, the influential technology columnist for The New York Times, complained in his PlayBook review that the PlayBook "does not have e-mail, calendar or address book apps of its own."
"You read that right," Pogue said. "RIM has just shipped a BlackBerry product that cannot do email. It must be skating season in hell."
Pogue noted that the PlayBook can play Flash video, which the iPad can't, but its GPS does not offer turn-by-turn navigation software.
The PlayBook has a seven-inch (17.8-centimeter) touchscreen, smaller than the iPad's 9.7 inches (24.7-cm) and at less than a pound (425 grams), the PlayBook is lighter than the iPad 2's 1.3 pounds (590 grams).
But Pogue said that although the PlayBook "looks and feels great," it is about half an inch too wide to fit into the breast pocket of a jacket.
Pogue and Walter Mossberg, the technology columnist for The Wall Street Journal, also pointed out that while Apple offers 300,000 applications for the iPad, RIM has just a handful for the PlayBook.
Mossberg said the PlayBook is more a "companion to a BlackBerry phone rather than a fully independent device.
"That may be fine for dedicated BlackBerry owners, but it isn't so great for people with other phones," Mossberg said. "I can't recommend the PlayBook over a fully standalone tablet, except possibly for folks whose BlackBerrys never leave their sides."
Forrester senior analyst Sarah Rotman Epps said the PlayBook is a work in progress.
"I see the PlayBook as a proof of concept for RIM's future direction more than a road-ready competitor today," Rotman Epps said. "Today, the PlayBook is a racecar that's missing a wheel, but it has high-speed potential for the future."
RIM co-chief executive Jim Balsillie, appearing on CNBC television, said the PlayBook is "super, super fast with true multi-tasking capability."
"You get the full Web with full Flash," Balsillie said.
"The most important thing for us is to have a future-proof operating platform for mobility," he said. "And we have that."
Apple sold over 15 million iPads last year and scores of other companies have been scrambling to release their own tablet computers in a bid to grab a share of the fast-growing market.