Supermarket giant Asda has vowed to shore up the number of women in top-level positions after revealing a 53% gap in the bonuses paid to men and women.
The Walmart-owned retailer said the yawning chasm was caused by more men working in senior roles, with women holding 35% of the jobs found in the upper echelons of the company.
Despite the disparity, its gender pay gap for all workers beat the national average, hitting 12.5% for mean hourly pay compared with a UK-wide figure of 17.4%.
On a median basis - which takes the middle number from a list of the lowest and highest values - the gap was 8.9%, in contrast with a national reading of 18.4%.
Hayley Tatum, Asda's senior vice president of people, said: "Rates of pay and access to benefits and opportunities are the same at Asda, regardless of gender.
"Whilst our gender pay gap is better than the national average, we recognise that, like many businesses, we have challenges when it comes to female representation in more senior roles - and that is something we're committed to addressing."
Asda, which has a 149,000-strong UK workforce, reported a mean and a median bonus gap of 52.5% and 21.5% respectively, despite offering a bonus scheme to all staff in the business.
The Government has demanded all organisations with a workforce of 250 or more people reveal their gender pay gap figures.
While the move is designed to highlight the pay gulf between the sexes, it is different from equal pay which tackles the difference between men and women who carry out the same job.
More than 1,000 organisations have published gender pay gap figures, with Government data showing around three in four are paying male employees more than female colleagues.
Based on median hourly earnings, 74% of companies pay men more than women, while 15% pay women more than men and 11% report no difference.