Data from the Professional Boards Forum shows that 16.7 per cent of FTSE 100 board seats are now held by women, up from 12.5 per cent in 2010.
This makes it increasingly likely that a government-approved diversity of employment target of having 25 per cent female directors by 2015 will be met, said the organisation.
One in four FTSE 100 companies have already reached the target set out in Lord Davies’s review, while only eight all-male boards remain, down from 21 when the target was initially set last year.
“The figures contradict recent reports that chairmen only recruit mirror images of themselves,” commented Elin Hurvenes, founder of The Professional Boards Forum.
“It also puts to rest the argument that board-ready women don’t exist. UK chairmen are doing a good job.”
Drinks brand owner Diageo currently has the highest proportion of female board representatives at 44 per cent, followed by Burberry (38 per cent), Pearson (33 per cent), GlaxoSmithKline (31 per cent) and Marks and Spencer (31 per cent).
However, noticeably less progress has been made among FTSE 250 companies, where just 10.9 per cent of board members are female, up from 7.8 per cent this time last year.
Some 98 (39.2 per cent) of boards among FTSE 250 representatives are entirely male boards, down from 52.4 per cent in 2011.
However, the figures reveal that here too the tide has began to shift towards greater gender equality, with 40 per cent of FTSE 250 board appointments since March 1st going to women.
The Professional Boards Forum’s report follows a recent study by Deloitte, which found that more than three-quarters of companies are actively trying to increase the number of women at board level.