Jordan Novet / CNBC: IBM CEO Ginni Rometty to step down on April 6, to be replaced by SVP of Cloud and Cognitive Software Arvind Krishna; Jim Whitehurst to become President  —  - Ginni Rometty has been executive chairman, president and CEO since 2012.  — Rometty has been at IBM for almost four decades; the next one has been there for three decades.