The Investment Association has written to 35 FTSE-350 companies asking them to explain their poor female representation at leadership level, as investors urge groups to move towards targets set out in the Hampton-Alexander Review.
FTSE 100 companies with all-male executive committees, such as BP and Smurfit Kappa Group, and companies whose combined executive committees and direct reports have low proportions of women, such as Persimmon and TUI, have been singled out to explain the steps they are taking to move towards an improvement in diversity.
In addition, the IA and the Hampton-Alexander Review have also written to 11 companies in the FTSE 250 who have all-male boards, including Sports Direct and Stobart Group, and ten companies who chose not to report their gender diversity data to the Hampton-Alexander Review last year, including The AA, J D Wetherspoon and Wizz Air.
The Hampton Alexander Review was initially published in 2016, and then again in 2017. Sir Philip Hampton and the late Dame Helen Alexander were commissioned by the government to look at ways to ensure that talented women at the top of business are recognised, promoted and rewarded, with a focus on senior women below the company board.
It aims to increase the number of women in senior positions in FTSE 350 companies to 33% by 2020.
The IA said UK investment managers collectively own one third of the FTSE and should be holding the biggest listed companies to account as investors want boards and leadership teams that are gender diverse. Diverse companies typically outperform their less diverse competitors and make better long-term decisions, said the trade body.
Chris Cummings, chief executive of the Investment Association, said: "The body of research is clear: firms with a diverse management team and pipeline make better decisions and drive innovation. The target of 33% for women in senior leadership positions by 2020 absolutely aligns with investors' desire to see the companies they invest in recognising diversity as a critical business issue.
"The Hampton-Alexander recommendations have now been in place since November 2016. Investors are becoming restless and want companies to take action.
"A number of key investors have told us that they will vote against AGM resolutions on the grounds of gender representation. With the AGM season now in full swing, companies who are falling short should take urgent steps to outline what they plan to do to increase diversity."
Sir Philip Hampton, chair of the Hampton-Alexander Review, added: "Whilst the majority of FTSE companies are taking great strides to address the lack of women on boards and in their leadership teams, it is disappointing to see a significant minority of companies still making slow or no progress. The gap between those working hard to improve gender balance and those doing very little, has never been more obvious.
"All FTSE companies adrift from 33% women's representation on their boards and in leadership, need to rise to today's challenge from the investment community and take swift action to address the lack of women in their top teams."
Meanwhile, Andrew Griffiths, Business Minister, commented: "Diversity at the very top of businesses has proven time and again to make for more effective leadership.
"While some of the UK's largest companies have made great strides in recent years to improve diversity in the boardroom, we need all FTSE 350 firms to pull their weight if we're to become a world leader on gender diversity."
The comments come as L&G Investment Management said it would be voting against boards that do not have 25% female representation.
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