IBM says its board has elected as its new chairman Virginia Rometty to succeed Samuel Palmisano when he steps down on October 1.

Ms Rometty, currently IBM's president and chief executive officer, will add the title of chairman at the US computing giant.

Mr Palmisano, who began his career with IBM in 1973 and became chairman in 2003, will remain a senior adviser to the company until he retires on December 1, an IBM statement on Tuesday said.

Ms Rometty, 55, began her career with IBM in 1981 in Detroit, Michigan, and was appointed chief executive on January 1.