In another blow for RIM, Sprint Pulls Plug on 4G PlayBook

Research in Motion was dealt another blow as Sprint announced that it won't be carrying the 4G enabled version of its Playbook tablet, dimming hopes that that iPad competitor will ever gain critical traction.

The wireless provider said that a lack of interest from potential business users was influencing its decision.

"We apologize for any inconvenience but the BlackBerry 4G PlayBook tablet that was announced in January for summer availability will no longer be coming to the Sprint network," the company said Friday.

The loss of a Sprint deal compounds the PlayBook's struggle, which also has not gained support from Verizon or AT&T either. That will also disappoint consumers looking for something that can work beyond WiFi connections, or do not have Blackberry's to tether to.

But RIM characterized the 4G PlayBook change as a reflection of its new focus on Long Term Evolution, or LTE wireless standards, but still hopes to push 4G tablets later this year.

"Testing of BlackBerry 4G PlayBook models is already underway and we plan to enter labs for network certifications in the US and other international markets this fall," the company said.

The setback highlights the struggle RIM is having as it tries to push into a tablet market dominated by Apple.

While the analysts predicts worldwide tablet computer market to 60 million units this year, up from 55 million previously, Apple should command almost 40 million units, or 66 percent of the market.

In contrast, the Blackberry maker cut its Playbook tablet shipment estimates to 2.5 million from 3.6 million for the entire year.