Despite a continued push for equality, men still earn more than women with the difference in wage remaining at 9.4%, the same level as in 2017/18, when figures were first published.
The analysis looked at a company’s median pay gap – the difference in pay between the middle-ranking woman and the middle-ranking man.
This is different to unequal pay – paying women less for the same work – which is illegal.
Equality charity The Fawcett Society said employers needed to “do more” to close pay gaps.
“If we are to see meaningful progress on closing the pervasive pay gap, employers must go further than data sharing,” said Jemima Olchawski, the organisation’s chief executive, who added companies needed to take concrete action.
By law, companies, charities and public sector departments of 250 employees or more must publish their gender pay gap figures on the Gender Pay Gap Service website.
It is part of a government initiative to force businesses to be more transparent about pay – by Tuesday afternoon, 9,824 employers had reported.
Banking and finance remain among the worst offenders, with women earning, on average, 22% less than their male colleagues. The industry has narrowed the gap by just 0.5 percentage points compared with five years ago.
The construction sector, meanwhile, narrowed the gap by 2.7 percentage points, but it remained highly unequal, with the average woman earning 78p for each pound a man earned. There are some businesses that pay women more than men including Airbus Operations (17.7%), Azebra Pay (16.9%) and DHL Services (12%).
But for many sectors, the gender pay gap has continued to widen. For example, in education, the pay gap has increased by 0.9 percentage points.
Ms Olchawski, from the Fawcett Society, said all employers needed to create an action plan which set out how they will improve gender equality in their workplace.
“Reporting is a good way of identifying pay inequalities, but taking action is key,” she said.
Large businesses that have some of the widest gaps in pay between men and women include Easyjet, Lloyds Bank, Savills and CVS pharmacy.
At Easyjet, despite an improvement from last year, the average woman takes home just 53p for every £1 earned by men.
Mona Abdelatti, a pilot for Easyjet, said that part of the challenge is more men than women are interested in professions like hers.
“For most people when they see a female pilot, it’s like a huge deal,” she said.
She acknowledged the training was an investment: “What I would say is that unless you love it, don’t make the investment, just because it is so much money.”