- Video report by ITV News Correspondent Juliet Bremner
New gender pay gap figures show women's average hourly salary is as much as 52% less than men's at some companies.
More than 500 organisations have published their gender pay gap figures, which reveal the difference in the average pay and bonuses for female and male employees.
At easyJet, the mean hourly rate for women was 52% lower than for men, while the figure stood at 15% lower for Ladbrokes and 33% lower at Virgin Money.
All three firms said men and women in the same roles were paid the same, and attributed the discrepancy in pay to having more men in higher-paid positions.
At airline easyJet just 6% of its pilots - who earn an average salary of £92,400 - are women, while females make up 69% of its cabin crew, earning £24,800 on average.
The firm said it was actively seeking to recruit more female pilots, with a target of 20% of new entrant pilots being women by 2020.
Ladbrokes Coral Group said the gender pay gap was "largely a function of weak representation at our senior levels", and said it was looking to improve gender representation.
Virgin Money said it was aiming to achieve a 50:50 gender balance by 2020 as it revealed that just 35% of employees in the highest paid quartile were women, compared to 73% in the lowest quartile.
The government made it mandatory for all organisations with 250 or more workers to report annually on their gender pay gap. Companies are required to publish the first set of data by April.
The gender pay gap is different to "equal pay", which deals with the pay differences between men and women who carry out the same jobs.
The BBC reported its mean hourly rate for women was 10.7% lower than for men, while the figure was 30% lower for the Co-operative Bank.
Steven Pickering, chief risk officer at the Co-operative Bank, said: "Like many banks, our gender profile means that we have a pay gap which reflects the number of men in senior roles compared to the number of women.
"Through our five-point action plan, we aim to achieve a material increase in the number of women in senior roles, which, in turn, will help reduce our gender pay gap."
Several of the organisations to have already published their figures reported low or no gender pay gap, including the British Museum (0%) and the UK Armed Forces (0.9%).
Cambridgeshire Police revealed women had a mean hourly pay of 13% more than men.