The firm says it expects to make a net operating loss of approximately $950 million to $995 million for the second quarter of its financial year.
Last month Blackberry’s board announced it was considering selling the business after a series of disappointing product launches and declining market share.
The company has been squeezed by the success of Apple’s iPhone and handsets running Google’s Android operating system.
Earlier this year it finally launched its much-delayed Blackberry 10 operating system and new phones to run it on, but has also persisted with releasing models running its older Blackberry 7 system aimed at consumers.
Most of the handsets activated in the most recent reported quarter were Blackberry 7 devices.
The firm says it will now focus “on enterprise and prosumer-centric devices” and reduce the number of handsets it offers from 6 to 4, comprising of 2 high-end models and 2 entry-level models.
In a statement the company said it would “refocus on enterprise and prosumer” customers.
Thorsten Heins, President and Chief Executive Officer of BlackBerry said, “We are implementing the difficult, but necessary operational changes announced today to address our position in a maturing and more competitive industry, and to drive the company toward profitability.
“Going forward, we plan to refocus our offering on our end-to-end solution of hardware, software and services for enterprises and the productive, professional end user. This puts us squarely on target with the customers that helped build BlackBerry into the leading brand today for enterprise security, manageability and reliability.”