More than 10,000 employers had published their gender pay gap reports, which the Guardian said showed women were being paid a median hourly rate which, on average, was 9.7% less than male staff. However, when all of its United Kingdom business was taken into consideration, it paid women on average 2% more than men.
A Guardian analysis of the data shows that in companies where women are fairly or slightly overrepresented in the top pay band, the median gender pay gap shrinks relative to the composition of the company as a whole.
Clear Channel UK for one may have to rebalance its pay scales in favour of men.
For Ticketmaster, the split in the top quartile for pay is more skewed in favour of men - 79% of the best-paid roles went to men.
Sam Smethers, chief executive of the Fawcett Society, described gender pay gap reporting as a "game changer" for workplace culture and practices.
More men receive bonuses at Ticketmaster - 56% compared to 45% - and there's a bonus gap of 64% (mean) and 31% based on the median measurement.
"Businesses should see reporting gender pay gap data as just the first step on the road to creating fairer and more equal workplaces across the United Kingdom", she said. More specifically, this means that women earn 36p for every £1 earned by a man.
In the legal sector U.S. law firm Kirkland & Ellis, the richest in the world, had a mean gender pay gap of 33.2 per cent and a median gender pay gap of 68.2 per cent, meaning that women earn 32p for every £1 men earn.
What is the gender pay gap?
WEF researchers have said it would take 217 years for disparities in the pay and employment opportunities of men and women to come to end, much longer than the 170 years they previously calculated no more than a year ago.
Elsewhere, the DfT-owned Highways England reported an average hourly pay rate for women that was 5.4% lower than for men.
"At first glance our mean bonus gap looks high".
It said it aimed to recruit an increasing number of women in graduate and experienced roles. Thirty one per cent of the most highly paid employees in the chain are women.
Women also earn considerably less in the energy sector, with a gap of 19.3 per cent at SSE, 30.5 per cent at Scottish Power, and 36.1 per cent at Scottish Hydroelectric Transmission.
Bonus pay was also massively gendered with women's mean bonus pay 62.3 per cent lower than men's and median bonus pay 74.3 per cent lower.
The figures from The Drum's sample show that United Kingdom marketing businesses have a median hourly pay gap of 16.2% in favour of men - slightly better than the UK-wide median of 18.4% - while media companies fared better, with an average median of 13.5%. By contrast, Adur district council reported a gap of 50.3% in favour of women.
"The challenge for employers is to decide whether to be sector leaders and demonstrate their commitment to gender equality, or to risk reputational damage by doing nothing", she added. "What we found out was, actually it's not about having more and more and more women, but it's having a balance of males and females which creates the maximum dynamic and creates a psychologically safe atmosphere".