20 September 2013 Last updated at 15:36 ET
Trading in Blackberry shares has halted on the Toronto Stock Exchange and the Nasdaq in New York.
The troubled smartphone maker said on Friday that it anticipated a loss when it reported its second-quarter figures next week.
Blackberry said that it may lose up to $995m (£621.1m).
It also expects to have to cut 40% of its worldwide workforce, 4,500 employees.
Source: BBC News - Business http://www.bbc.co.uk/news/business-24182038#sa-ns_mchannel=rss&ns_source=PublicRSS20-sa