Fairfax, the biggest investor in beleaguered BlackBerry, has snapped up an additional $250 million in convertible bonds issued by the Canadian firm.

An investment firm and insurer, Fairfax is exercising an option granted with the $1 billion BlackBerry raised through the issue of convertible notes back in November.

At that time, Fairfax was in for $250 million and joined by a range of investors, including Canso Investment Counsel, Mackenzie Financial, Markel Corp, Qatar Holding, and Brookfield Asset Management.

Fairfax had previously failed to secure the necessary funds for a rumoured $4.7 billion bid to take BlackBerry private.

The doubling of Fairfax commitment on BlackBerry debt may well be seen as a vote of confidence in John Chen, BlackBerry’s new CEO (he is no longer the interim CEO).

Chen has assembled a new management team, the latest addition being industry veteran Ron Louks as president of devices and emerging solutions.

Under Chen, BlackBerry is now focusing its efforts around four operating units: Enterprise Services, Messaging (its BBM activities), QNX Embedded and Devices.

The Canadian company has also entered a five-year strategic partnership with contract manufacturer Foxconn to jointly develop and deliver devices – initially a smartphone for Indonesia and other fast-growing markets reportedly targeted in early 2014.

Fairfax owns 9.9 percent of BlackBerry’s shares. The new issue of notes, convertible at $10 a share, would increase the firm’s stake to 17.6 per cent (if no other debt holders converted their bonds).

If all the others did so, reports Bloomberg, Fairfax’s stake in BlackBerry would be 15.6 per cent.

The Fairfax $250 million transaction is to be completed on or before 16 January.