A Research in Motion management shake-up has swapped out its co-CEOs for a new top exec following a challenging period for the gadget maker.

Jim Balsillie and Mike Lazaridis, RIM's co-chief executives, have stepped aside after 20 years at the trouble biz, and the company on Monday named Thorsten Heins as president and CEO.

Lazaridis co-founded RIM in 1984 while Balsillie joined in 1992. A relatively unknown insider, Heins joined RIM in 2007 from Siemens' Communications Division and served as chief operating officer of product engineering.

Lazaridis and Balsillie are not entirely gone, however; Lazaridis remains on RIM's board as vice-chairman and as chair of the board's new innovation committee while Balsillie remains simply as a board member.

The pair have finally resigned as their company's troubles mounted.

Sales have dropped and profits have fallen, disappointing shareholders and prompting calls for changes to strategy and direction. One factor for discontent was the disappointing PlayBook, RIM's supposed answer to the super-soaraway Apple iPad. Launched with a flourish and much promise by management, sales fizzled and RIM was forced to cut prices simply to shift units.

The PlayBook was a strategic play for RIM; in 2010 it bought QNX Software Systems whose Neutrino embedded operating system became the basis of the PlayBook's OS.

While the PlayBook sank, RIM's traditional phone business has also been under pressure: market share for the BlackBerry has been under attack from Apple's iPhone and devices running Google's Android, and RIM has seen its market share decline. ®