A screen shot from Angry Birds.

It took seven months, but Research In Motion has finally delivered on a promise made by co-founder Mike Lazaridis to make Angry Birds available on RIM's PlayBook tablet.

The hugely popular game, in which birds destroy the pigs who stole their eggs with the help of a slingshot, has long been available on Apple and Android-based devices.

But its absence had become symbol of the relative dearth of consumer-friendly applications available for RIM's PlayBook, a business-focused device which is powered by QNX software the company expects to use on make-or-break BlackBerry smartphones from late next year.

The PlayBook, which RIM launched to scathing reviews in April, has sold less than 1 million units, while Apple sold more than 11 million iPads in just its most recent quarter.

The game, which developer Rovio says has been downloaded 600 million times, is not available on RIM's current smartphone lineup, which uses an older operating system.

Each of the three versions listed on the BlackBerry App World website costs $4.99. A limited version of the game is available for free for Apple and Android devices.

RIM stock rose more than 11 percent to $13.91 on the NASDAQ Wednesday after a report late Tuesday that the Canadian company had rebuffed offers from amazon.com and other potential buyers.

But the stock is still down more than 70 percent this year, and it remains below already-depressed levels seen before the company released its latest earnings report last week.

ThinkEquity analyst Mark McKechnie upgraded RIM to "buy" from "hold" Wednesday, saying that the share price slump undervalues the company and that an acquisition could value it at around $25 a share.

Jefferies analyst Peter Misek moved to "hold" from "underperform", citing a potential partnership or buyout as putting a floor underneath the stock.

Reuters