Research by recruitment firm Robert Half found that the average chief executive in the FTSE100 is a 54-year-old man - a profile unchanged in the past two years, while 19 are Oxbridge graduates.
The number of women CEOs remains "persistently low" at just four, although one fifth of senior positions in boards are held by women.
Phil Sheridan, managing director at Robert Half, said more advertising and marketing specialists were being appointed to top posts.
But he said: "The old guard of finance still holds sway, with executives with a background in accountancy and finance holding the reins of the UK's top companies.
"The biggest disappointment is that the number of women FTSE100 CEOs has remained consistently low since we began this study in 2008."