BlackBerry-maker RIM is to phase out the cheapest version of its poorly-selling PlayBook tablet in an apparent bid to streamline its product offerings in the tablet space.

Reuters reports that RIM is to phase out the entry-level 16GB PlayBook once current stocks are depleted, but will continue to produce the 32GB and 64GB versions of the device, which are understood to offer better margins.

RIM sold the 16GB version for US$199, while the 32GB and 64GB models are priced at US$249 and US$299, respectively.

"We continue to remain committed to the tablet space and the 32GB and 64GB models of the BlackBerry PlayBook continue to be available from our distributors and retailers around the world," RIM said.

Launched last year, RIM is thought to have sold only around a million PlayBooks to date, despite sharp discounts and a major software overhaul designed to add some of the basic features (such as email) it was criticised for lacking in the early versions.

Earlier this week, RIM also announced a beta release of its Tablet OS 2.1.0 platform, enabling developers to test apps on the next-generation version of the PlayBook OS.

The firm said last month that it currently has 15,000 apps available for the PlayBook, up from just 2,000 last year.