BlackBerry maker Research In Motion's co-chief executives, Jim Balsillie and Mike Lazaridis, are stepping down, the company said.
RIM said the pair, who founded the company, would be replaced by Thorsten Heins, a chief operating officer who joined RIM four years ago from Siemens AG.
Mr Balsillie and Mr Lazaridis have headed Ontario-based RIM together for the past two decades.
The company took a big slide in 2011, dropping behind its peers in the lightning-paced smartphone market, suffering through the worst service blackout in its history and losing tens of billions in market value.
In addition, the PlayBook tablet, RIM's answer to the Apple iPad, failed to gain consumer support, forcing the company to give it deep discounts to move the devices off store shelves.
"There comes a time in the growth of every successful company when the founders recognise 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," Mr Lazaridis said in a statement.
The company has suffered a series of setbacks and has lost tens of billions in market value. It was once worth more than 70 billion dollars (£45 billion) a few years ago, but now has a market value of 8.9 billion (£5.7 billion).
Mr Lazaridis will take on a new role as vice chairman of RIM's board and chairman of the board's new innovation committee. Mr Balsillie remains a member of the board.
"I agree this is the right time to pass the baton to new leadership, and I have complete confidence in Thorsten, the management team and the company," Mr Balsillie said in the statement.
"I remain a significant shareholder and a director and, of course, they will have my full support."
© 2012 Press Association