Eric Risberg, File, Associated Press
FILE - In this Oct. 18, 2011 file photo, Mike Lazaridis, co-CEO of Research in Motion gestures at the end of his keynote address to the BlackBerry DevCon Americas conference in San Francisco. Research In Motion Ltd. reports quarterly financial results Thursday, Dec. 15, 2011, after the market close

TORONTO — BlackBerry maker Research in Motion's co-CEOs, Jim Balsillie and Mike Lazaridis, announced Sunday they are stepping down from the once-iconic company that has struggled to compete in recent years.

The RIM founders will be replaced by Thorsten Heins, a chief operating officer who joined RIM four years ago from Siemens AG, RIM said.

Balsillie and Lazaridis have headed Waterloo, Ontario-based RIM together for the past two decades.

The Canadian company has suffered a series of setbacks and has lost tens of billions in market value.

RIM said last month that new phones deemed critical to the company's future would be delayed until late this year. And its 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.

Many shareholders and analysts have said a change has been needed, blaming Balsillie and Lazaridis for poor performance. A company that was worth more than $70 billion a few years ago now has a market value of $8.9 billion.

"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," Lazaridis said in a statement.

Lazaridis will take on a new role as vice chairman of RIM's board and chairman of the board's new innovation committee. 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," Balsillie said in the statement. "I remain a significant shareholder and a director and, of course, they will have my full support."

Analysts have said RIM's future depends on its much-delayed new software platform. RIM needs to come up with a compelling BlackBerry as U.S. users have moved on to flashier touch-screen phones such as Apple's iPhone and various competing models that run Google's Android software.

Heins said Lazaridis and Balsillie took RIM in the right direction and said he's committed to the new software platform.

"We are more confident than ever that was the right path. It is Mike and Jim's continued unwillingness to sacrifice long-term value for short-term gain which has made RIM the great company that it is today. I share that philosophy and am very excited about the company's future," Heins said.

Barbara Stymiest, a former chief operating officer of the Royal Bank of Canada who has been a member of RIM's board since 2007, has been named the independent board chair.

Balsillie and Lazaridis have long been celebrated as Canadian heroes, even appearing in the country's citizenship guide for new immigrants as models of success.