FTSE 100 companies fail to promote women to the roles most likely to lead to the top job as chief executive, according to a new study.

Research by campaign group 25×25, an organisation working to increase the number of female CEOs, says that the route to a CEO’s office is generally through a position as a divisional head.

Currently, 44% of the FTSE 100 CEOs are former divisional heads. Yet the study finds that women account for only 19% of the divisional head roles currently in the UK’s largest companies. Only 9% of the FTSE 100 companies are led by women.

Tara Cemlyn-Jones, 25×25’s chief executive, says the root cause of why so few women reach the top—despite women representing 48% of the UK workforce—may run deep.

“Executive gender balance is a good indicator of how robust an organisation’s succession and talent planning is, because women account for almost half the working population,” she says.

“If no woman is getting through to a senior decision-making position, this suggests a structural or cultural issue.”

The report by 25×25 finds that while 44% of FTSE 100 CEOs were once divisional heads, 19% were previously CFOs, 14% heads of operations and supply, while 13% were CEOs in a previous role.

The study shows only 19% of current divisional heads are women, though 25% of FTSE 100 CFOs are women. Women also hold 21% of operations and supply roles.

Falling flat

The report concludes that “the concept that talented women will ‘bubble up’ into senior positions by virtue of volume is unfounded.”

Given the lack of women in CEO feeder roles, 25×25 says gender imbalances have become a “self-perpetuating cycle”.

The report says: “This means that if boards aren’t tracking their [talent] pipelines accurately, the number of women achieving senior decision-making roles will remain too low.”

It adds: “The fact is, whatever the longer-term ambition, CEOs and boards need to keep focused on probable pathways if they wish to improve their executive gender balance in the near future.”

At the time of the study this year, only 4.9% of FTSE 350 CEOs were women. That compares to 33% of MPs in the House of Commons, 47% of permanent secretaries, 40% of barristers, 53% of solicitors and 42% of judges.

There has been some progress in improving the gender balance on boards, though that tends to be through the appointment of female non-executive directors.

However, it has been recognised for some time that the same progress was failing to happen at executive level.

In recent months, the issue of boardroom gender balance has become controversial after studies claiming diverse boards improve company performance came under fire for building conclusions from poor methodologies.

Ethical considerations

Many have argued that the argument for women and other minority groups on boards should shift from claims about improved performance to ethical and representational arguments.

In October, UK parliamentarians called for all listed companies to reach a target of having 40% of their executive positions held by women. The MPs also called for companies to report on post-maternity retention rates.

Conservative MP and chair of the committee Alexander Stafford said at the time: “The materiality of equality is indisputable and this needs to feed through to our corporate governance regime.

“We are seeing positive signs, but we can go further.”

Solving problems is mostly achieved through addressing root causes; 25×25’s report goes some way to shining a light on why women are not reaching the top jobs at FTSE 100 firms.