TORONTO — BlackBerry maker Research In Motion Ltd., already­ struggling with plunging sales, said Thursday that it lost subscribers for the first time in the latest quarter, as the global number of BlackBerry users fell to 79 million.

It is preparing to launch new smartphones deemed critical to its survival Jan. 30.

Three months ago, RIM had 80 million subscribers.

RIM is banking its future on a much-delayed BlackBerry 10 platform, meant to offer the multimedia, Internet browsing, and apps experience customers now demand.

RIM posted net income of $14 million, or 3 cents per share, for the quarter ended Dec. 1. That compared with a profit of $265 million, or 51 cents, a year earlier.

The latest figure includes a favorable tax settlement. Excluding that adjustment, RIM lost 22 cents per share.

Revenue of $2.7 billion was down 47 percent.