Female FTSE 100 directors earn on average 73% less than their male counterparts, according to analysis by New Street Consulting Group.
Its research found that the average pay package for a female director in the FTSE 100 is £237,000, compared to £875,900 for male directors.
Claire Carter, a director at the consultancy, said the focus on boosting female director numbers in top companies was not going far enough.
“Focusing solely on percentages of directors that are women is not enough when trying to approach equality,” she said.
Ninety-one percent of female directors in FTSE 100 companies are in non-executive roles, which could also explain the wage gap.
Where women were in executive director roles, their average pay was £1.5 million, compared to £2.5 million for their male counterparts.
Research by recruitment specialists Green Park earlier this month revealed that the number of white men in the ‘top 40’ positions in FTSE 100 companies is on the rise, despite efforts to improve boardroom diversity.
Female and ethnic minority leaders were largely consigned to roles in HR, diversity and marketing, it found, commanding lower salaries and less influence.
“Most businesses want to end the old boys club that exists at the top. The key to doing that will be ensuring that women have more executive responsibilities and are trained and prepared properly for taking on that responsibility,” Carter added.
“Ultimately the catalyst for change lies with the boards themselves.It will be a case of their examining whether there are any barriers that are preventing females from reaching the very top at their organisation, and if there’s anything they can do to help overcome these.”