An analyst said on Thursday that BlackBerry maker Research In Motion may have halted production of its PlayBook tablet computer and canceled additional tablet projects.

We believe RIM has stopped production of its PlayBook and is actively considering exiting the tablet market, Collins Stewart semiconductor analyst John Vihn wrote in a note.

He cited last week's news that contract manufacturer Quanta Computer had laid off a significant number of workers at a factory focused on producing the PlayBook.

Additionally, our due diligence indicates that RIM has canceled development of additional tablet projects, he wrote.

The PlayBook has failed to make much headway in a tablet market dominated by Apple's iPad and in which on Wednesday launched a content-rich and cheaper product called the Kindle Fire.

RIM said it shipped 500,000 PlayBooks in the last six weeks of its fiscal first quarter and another 200,000 in its full second quarter.

RIM was not immediately available to comment on the Collins Stewart report.

If true, RIM won't be the first to walk away from tablets. Hewlett-Packard abandoned its TouchPad last month after just seven weeks on shelves.

(Reporting by Alastair Sharp; editing by Peter Galloway)