Dr Ruth Sealy, author of the , 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.