IBM announces first female CEO

Palmisano said Rometty would be perfect to lead IBM into its second century. "She has spurred us to keep pace with the needs and aspirations of our customers by deepening our expertise and industry knowledge. Ginni's [Virginia] long-term strategic thinking and client focus are seen in our growth initiatives, from cloud computing and analytics to the commercialisation of Watson [an artificial intelligence computer system capable of answering questions posed in natural language]."

Rometty is currently responsible for sales, revenue and profit in 170 global markets. She joined IBM in 1981 as a system engineer, holding a bachelor of science with honours in computer science and electrical engineering from Northwest University. She later became senior vice president for Global Business Services, in which role she lead the integration of PricewaterhouseCoopers Consulting to create a team of 100,000 business consultants and services experts.

"Sam had the courage to transform the company based on his belief that computing innovation, our industry, even world economies would shift in historic ways. All of that has come to pass. Today, IBM's strategies and business model are correct," Rometty said.