Blackberry manufacturer Research in Motion (RIM) has reported a quarterly loss, due in part to falling revenues on the back of weak smartphone shipments.
The Canadian company made a net loss for the three months to 3 March of $125m (�78m), compared with a profit of $934m a year earlier.
Revenues fell to $4.2bn from $5.2bn.
The firm also suggested it would refocus on the corporate market rather than on individual consumers.
It also announced the resignation of former co-chief executive Jim Balsillie.
Chief technology officer David Yacht will also be standing down.
Shares in the company fell as much as 9% in after-hours trading following the trading statement. They have fallen by 80% over the past year.
Shipments of BlackBerry smartphones in the quarter fell to 11.1 million, down 21% from the previous three-month period.
Shipments of the company's PlayBook tablets hit 500,000, largely due to substantial discounting.
For the full financial year, the company made a net profit of $1.2bn, down from $3.4bn in the previous year.
The results were worse than analysts had expected and RIM shares fell sharply in after-hours trading. Corporate focus
RIM has struggled to keep up with rivals in the smartphone market, such as Apple's iPhone and handsets running on Google's Android operating system.
It has also struggled to gain a foothold in the tablet market.