The interim C-E-O of Waterloo-based BlackBerry says he has his work cut out for him as he tries to fix the fortunes of the flagging company.

John Chen's comments come as the smartphone maker reported staggering third-quarter losses of 4.4 billion dollars today.

Poor sales of the latest BlackBerry phones weighed on the company's revenue -- which was 1.2 billion dollars, down 56 per cent from a year ago.

Since taking over last month, Chen has started a dramatic overhaul of BlackBerry's executive ranks and begun fresh efforts to turn things around.