Almost a third of board members of the 20 biggest publicly listed companies in Ireland are now women, up from 18% four years ago.

However, new data from the Balance for Better Business (B4BB) campaign also shows that across the boards of the other publicly listed firms here, the average rate of female board representation is 23%.

The research shows that 19 of the 39 listed boards have now met the key representation target level of 30%.

Four have passed the 40% representation mark, while a further two now have boards that are split 50:50 female to male.

"Continued progress towards targets is very encouraging and supports our view that the voluntary target approach is working for Irish business," said Julie Sinnamon, co-chair of B4BB.

"We would like to see many more individual companies reaching targets and enhancing their gender representation at all levels in their pipelines to ensure a consistent supply of future talent for leadership teams and for boards."

At leadership team level, B4BB said 26% of top executives in ISEQ20 companies are now women.

Across listed companies though, this figure drops to 21%.

When it comes to appointments, 38% of appointees to boards in listed businesses are women and on leadership teams the rate falls to 29%.

"We are pleased to see that the metrics are moving in the right direction however, the gap between progress on boards and that of leadership teams highlights the need for a programmatic and measurable approach to be put in place to address this issue," said co-chair Aongus Hegarty.

"The positive trend demonstrates that change can be achieved but in order to have long-term, sustainable progress we need a focus on succession planning at both board and leadership levels."

"The fact that the number of female Chair, CEO and CFO appointments is low shows that there is still a significant amount of work to be done."

The numbers were released by B4BB to mark International Women's Day.

Set up four years ago by the Government and led by business groups, B4BB aims to ensure that more women play a role at board level and in senior leadership teams.

"I launched Balance for Better Business in 2018 and although we have seen some significant progress since then, the share of women on the largest listed company boards has gone from 18% in 2018 to 32% today, for example, there is still much more to do," said Tánaiste and Minister for Enterprise, Trade and Employment, Leo Varadkar.