She was chairman of Incisive Media between October 2009 and December 2014 and played a key role in the development of the business.
Dame Alexander held a number of influential business roles during her career including chief executive of The Economist Group between 1997 and 2008, and board roles at Rolls-Royce and Centrica. She also led the CBI between 2009 and 2011 in the wake of the financial crisis.
Throughout her career, Dame Alexander was seen as a trailblazer for women in business. Alongside Sir Philip Hampton, she headed the Hampton Alexander Review, which focused on boosting the role of women in senior business positions.
Among her many roles, Oxford-educated Dame Helen was a non-executive director of PA Group, parent company of the Press Association, and at BT Group and Huawei UK.
“Her success owed much to a leadership style that lacked fireworks and did not seek fame, but deserved more recognition, for both its humanity and effectiveness,” the newspaper said in an article on its website.