The chief financial officer role is the main route to the boardroom for women, the author of the study of the number of women on boards told CFO World.
Dr Ruth Sealy, author of the Cranfield School of Management report Milestone or Millstone?, said a higher proportion of female executive directors came from a financial background than their male counterparts.
Of the 20 female executive directors in FTSE 100 companies, nine were in the CFO role. Among those companies with female CFOs were Diageo, British Land, Standard Life and Cairn Energy.
"For women to get to executive director, the CFO route seems to be the 'easiest' way to do it," Sealy said
"If you look at the proportion of female executives who have come through the CFO route, it is substantially more than the proportion of male directors. It seems to be something that is quite important for women who want to get to that level."
Sealy said Cranfield has begun another piece of research looking at the role of financial qualifications in getting more women on to the board, in conjunction with ACCA. The interim report will be released next month.
The percentage of female directors in the FTSE 100 increased to 15 percent from a three-year plateau of 12 percent, according to Sealy's latest report published on Tuesday. However, the percentage of women in executive directorship roles lagged those of non-executive positions, the report said.
Sealy said that recruiting more women into executive director roles will "take more application on the part of the organisations".
"It's a longer term [process] but that will provide the sustainability for keeping the percentages good," she added.
"It requires different actions and they are not yet being addressed properly."
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