Research In Motion won't upgrade the software for its much-maligned PlayBook until February, months behind schedule, and the tablet computer still won't feature the popular BlackBerry Messenger application after the makeover.

The Canadian company that makes the BlackBerry smartphone introduced the PlayBook tablet last April, rushing out a product to compete with Apple's wildly successful iPad, which essentially invented the category.

But the RIM entry wasn't well-received. Technology writers, financial analysts and consumers alike scorned the PlayBook because it could not handle the in-built email, calendar and contact applications that made the BlackBerry a household name.

At the time of the launch, RIM said it would add email and other features within 60 days. It later pushed the deadline back to the summer months and then to October.

The latest delay was announced on RIM's official blog late Tuesday.

As much as we'd love to have it in your hands today, we've made the difficult decision to wait to launch BlackBerry PlayBook OS 2.0 until we are confident we have fully met the expectations of our developers, enterprise customers and end-users, wrote David Smith, a senior vice-president for the PlayBook.

The setback comes two weeks after tens of millions of BlackBerry users across five continents suffered up to four days without service.

Following prior product and software delays and the recent outage, this represents another execution stumble, RBC Capital Markets analyst Mike Abramsky wrote in a note to clients.

(Reporting by Alastair Sharp in Toronto and Maneesha Tiwari in Bangalore; editing by Frank McGurty)