Morgan Stanley announced late Thursday current CEO John J. Mack will step down in January 2010 but will continue as chairman.

Mack,64, will be succeeded by Co-President James P. Gorman.

Robert Kidder, lead director of Morgan Stanley, said in a statement that Mack told the board 18 months ago he wanted to step back from the CEO role when he turns 65 in November.

Morgan Stanley has been under Mack's leadership for four years.

Mack guided Morgan Stanley through the financial crisis that claimed competitors Lehman Brothers and Bear Stearns.