WATERLOO,Ontario ( TheStreet) -- Research In Motion ( RIMM) said its co-CEOs Jim Balsillie and Mike Lazaridis have stepped down and been replaced by Thorsten Heins, the BlackBerry maker's chief operating officer. The resignations of Balsillie and Lazaridis come as smartphone users turn to devices made by Apple ( AAPL) and Google ( GOOG). "There comes a time in the growth of every successful company when the founders recognize the need to pass the baton to new leadership. Jim and I went to the board and told them that we thought that time was now," said Lazaridis, in a statement. Lazaridis has been named vice chairman of RIM's board and chair of the board's new innovation committee. Balsillie remains a board director. Both Lazaridis and Balsillie remain two of the company's largest shareholders. Heins, who joined RIM four years ago from Siemens, takes over for a company which has seen sales plunge and its stock tumble almost 90% from its peak in 2008. The stock closed Friday at $17, down 3.2%. Shares are rising to $17.99 in premarket trading Monday. -- Written by Joseph Woelfel >To contact the writer of this article, click here: Joseph Woelfel >To submit a news tip, send an email to: firstname.lastname@example.org.