The Canadian company said people were delaying buying the phones because they were waiting for the launch of the new BlackBerry 10 smartphone, due to go on sale at the end of January.
The Nasdaq-listed company said it now had 79m subscribers compared to 80m last quarter.
Smartphone shipments fell from 7.4m in September to 6.9m over the same period.
It meant third-quarter revenues halved year on year down to $2.7bn (£1.66bn), versus $5.1bn in 2011, leading to an adjusted net loss of $114m.
But shares spiked in the firm after it beat Wall Street expectations, which had forecast heavier losses.
The firm is amassing a cash war chest ahead of the launch of the BlackBerry 10 next month.
It boosted the value of its cash holdings and investments from $2.3bn to $2.9bn over the third quarter, it said yesterday.