CEO Thorsten Heins steps down, replaced by interim CEO John Chen.
Plans for Blackberry to be sold to its biggest shareholder Fairfax Financial Holdings have been cancelled.
Fairfax, which holds a 10% share in the smartphone producer, was planning to lead a consortium of firms in a takeover worth $4.7bn.
Instead, Blackberry now hopes to raise $1bn (£627m) of finance as chief executive Thorsten Heins leaves the firm. Former Sybase chief executive John Chen will serve as interim CEO.
Last month, Blackberry reported a second-quarter net loss of $965m, which was put down to disappointing sales of its new Z10 smartphone.
Fairfax, which had reportedly struggled to raise the funds needed for the takeover deal, is contributing $250m to the new fund-raising.
Barbara Stymiest, chair of Blackberry’s board of directors, said: "This financing provides an immediate cash injection on terms favourable to Blackberry, enhancing our substantial cash position."
In September, Blackberry announced plans to cut 40% of its workforce, 4,500 jobs.
Chen commented: "Blackberry is an iconic brand with enormous potential, but it’s going to take time, discipline and tough decisions to reclaim our success."