The founders and co-CEOs of Canadian telecoms company Research In Motion, Jim Balsillie and Mike Lazaridis resigned, paving the way for a change at the helm of the BlackBerry phone-maker. \"There comes a time in the growth of every successful company when the founders recognize the need to pass the baton to new leadership,\" Lazaridis said in a statement. He added that the company was \"entering a new phase, and we felt it was time for a new leader to take it through that phase and beyond.\" Lazaridis will continue working at the company as vice chairman of its board and chairman of a new innovation committee, offering \"strategic counsel\" and promoting the BlackBerry brand worldwide. Balsillie will remain a member of the board of directors. \"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,\" he said. German-native Thorsten Heins, who joined RIM in December 2007 from the industrial conglomerate Siemens AG, will become the new president and chief executive officer. Prior to Sunday\'s announcement, he was one of RIM\'s two chief operating officers and, before that, senior vice president for the Handheld Business Unit. In a statement, Heins said he was confident that RIM was on the right path. \"We have a strong balance sheet with approximately $1.5 billion in cash at the end of the last quarter and negligible debt,\" he noted. \"We reported revenue of $5.2 billion in our last quarter, up 24 percent from the prior quarter, and a 35-percent year-to-year increase in the BlackBerry subscriber base, which is now over 75 million.\" But according to industry tracker comScore, BlackBerry maker Research In Motion\'s share of the US smartphone market declined during the three months ending in November, while Apple and Google\'s Android platform both made gains. The Waterloo, Ontario-based RIM saw its share of US smartphone subscribers fall to 16.6 percent at the end of November from 19.7 percent at the end of August, according to comScore. Android was the top smartphone platform with a 46.9 percent share of the US market at the end of November, up from 43.8 percent. Apple\'s market share also rose during the period -- by 1.4 percentage points to 28.7 percent. Microsoft, meanwhile, saw its share of the smartphone market fall to 5.2 percent from 5.7 percent. RIM has been struggling in recent months and has been the subject of persistent takeover speculation.