Shares of Research In Motion Ltd. fell more than 8.6 per cent in after hours trading after the Waterloo, Ont., BlackBerry maker reported fourthquarter earnings that contained guidance numbers that failed to meet Wall St. expectations.

RIM said that revenue for the fourth quarter was $5.6 billion U.S., just short of consensus estimates of $5.64 billion.

Still, RIM's revenue total was up one per cent over the $5.5 billion the company generated in the third quarter and up 36 per cent over the same period last year.

During the quarter, RIM shipped about 14.9 million BlackBerry devices, a new record for the company, topping the previous record of 14.2 million BlackBerry smartphones that were shipped in the previous quarter.

RIM reported earnings of $1.78 per share, which was slightly higher than analyst expectations of $1.76.

Net income for the quarter was $934 million, up from $911 million in the previous quarter and $710 million in the fourth quarter last year.

RIM said that revenue for the fiscal year ended Feb. 26, 2011 was $19.9 billion, up from $15 billion in fiscal 2010.

"We are pleased to report record shipments and financial performance in fiscal 2011," RIM co-chief executive and co-chairman Jim Balsillie said in a statement.

"As we enter fiscal 2012, RIM is in an excellent position to benefit from the continuing convergence of the mobile communications and mobile computing markets.

"We are laying a strong foundation for RIM's expanding market opportunity through focused investments and we are extremely excited about our smartphone, tablet and platform road maps."

RIM said it expects revenue for the first quarter of fiscal 2012 to be between $5.2 billion and $5.6 billion, with earnings of between $1.47 and $1.55 per share diluted. Gross margins are expected to be approximately 41.5 per cent.

Analysts had anticipated guidance of about $1.66 per share.

RIM said the $400-million range in its guidance was due to the lower average selling price of Black-Berry devices expected in the coming quarter, as well as increased spending on research and development and marketing.

Like many other technology companies that rely on Japan for parts and electronics, RIM said its guidance range is slightly wider than normal to "reflect the risk of potential disruption" in the company's supply chain as a result of the recent earthquake.