Research In Motion, the maker of the BlackBerry Curve 3G, above, reported quarterly financial results Thursday. Research In Motion, the maker of the BlackBerry Curve 3G, above, reported quarterly financial results Thursday. Paul Sakuma/Associated Press

Shares in Waterloo, Ont.-based Research In Motion fell in after-hours trading Thursday as the BlackBerry maker's profit forecast disappointed investors despite an earnings boost.

RIM reported a 32 per cent increase in fourth-quarter earnings compared with the same period a year earlier, making $934 million US, or $1.78 US a share, on revenue of $5.6 billion.

Analysts had expected the firm to report earnings in the range of $1.74 to $1.76 a share and $5.6 billion in revenue. RIM does its accounting in U.S. dollars.

While earnings were better than expected, the company's forecast for earnings and sales in the current period disappointed markets.

In extended hours trading, its Nasdaq-listed shares lost more than 10 per cent, to $57.35 US.

The company predicted profits in the current quarter of $1.47 to $1.55 a share on revenues of $5.2 billion to $5.6 billion. The markets had been expecting about $1.65 per share and revenues of $5.6 billion. The company reported a profit of $710 million, or $1.27 per share, on revenue of $4.08 billion in the same period last year.

PlayBook launch as important as 1st BlackBerry: RIM

RIM will enter the tablet market on April 19, when it launches its BlackBerry PlayBook at more than 20,000 retail outlets in the U.S. and Canada.

It said that launch is expected to be as important as the debut of its first BlackBerry.

Co-chief executive Jim Balsillie said a number of Fortune 500 companies will be trying out PlayBooks in the coming weeks as the Canadian company fights for market share against Apple's iPad and tablets using Google's Android operating system.

"The launch of the PlayBook may well be the most significant development for RIM since the launch of the first BlackBerry in 1999," Balsillie told analysts.

Balsillie also said a new generation of smartphones using the operating system in the PlayBook will be released later this year.