Hewlett-Packard Co. said Tuesday that Patricia Dunn will step down as chairwoman of the San Jose, Calif.-based computer and printer maker in January amid a widening scandal involving a possibly illegal probe into media leaks. She will be succeeded by CEO Mark Hurd.

Hurd will retain his existing positions as chief executive and president, and Dunn will remain as a director after she relinquishes the chair on Jan. 18.