Morgan Stanley (MS) chairman and CEO John Mack will step down from his CEO role at the end of the year after steering the firm through one of the most significant financial crises since the Great Depression. He will be replaced by current Morgan Stanley co-president James Gorman. Mack, 64, will retain his position as chairman, and Gorman will join the firm’s board of directors. Morgan Stanley’s second co-president Walid Chammah will assume the role of chairman of Morgan Stanley International and will continue to be based in London. The changes take effect Jan. 1, 2010. Mack spent more than 20 years of his career at the firm, but left in 2001. He returned to take the reigns as CEO in 2005 and has been responsible for stabilizing Morgan Stanley during the financial crisis, board director Robert Kidder said, including overseeing the firm’s conversion to a bank holding company, strengthening the company’s capital position and repaying the its Troubled Asset Relief Program (TARP) infusion. Mack notified the board 18 months ago of his intent to step down from the CEO role after his upcoming 65th birthday in November. “Given our tremendous progress, we believe now is the right time for that transition, and all of us on the board - and across the firm - are grateful that we will continue to benefit from John's insights and experience in his critical role as chairman,” Kidder said. Gorman, 51, has served as co-president of the firm since 2007, charged with overseeing Morgan Stanley’s global wealth management business, investment management business and operations and technology group. Earlier this year, he was named chairman of the Morgan Stanley Smith Barney joint venture. “Succession has been a top priority for me since my return to Morgan Stanley, and I am confident that James is the right person to lead the firm forward,” Mack said. Write to Austin Kilgore.