(Telecompaper) BlackBerry's COO, CFO and CMO are stepping down, following the recently announced departure of CEO Thorsten Heins and completion of the smartphone maker's strategic review. The company did not announce replacements for COO Kristian Tear or CMO Frank Boulben. John Chen, BlackBerry's new CEO, said he will work more directly with the engineering and sales and marketing teams, suggesting the top marketing and operating positions will be eliminated. James Yersh, previously senior VP, controller and head of compliance at BlackBerry, will replace Brian Bidulka as CFO. Bidulka will stay on as a special advisor to the CEO for the remainder of the fiscal year to assist with the transition. BlackBerry also announced that Roger Martin, a board member since 2007, has resigned. The company said it will provide more details when it reports quarterly results on 20 December.