The troubled smartphone company Blackberry says it is no longer for sale and is replacing its chief executive officer.

John Chen, a US-based technology executive with a reputation for turning around troubled companies, replaces Thorstein Heins, who had been Blackberry's CEO for less than two years.

The announcement came on the day Fairfax, a Canadian private equity firm, was due to finalise plans to buy Blackberry for $4.7bn.

But as Al Jazeera's Daniel Lak reports from Toronto, the company's surprise announcement has sent the company’s shares tumbling.

Source: Al Jazeera