Women aged over 46 years old are earning a third less than their male colleagues, according to a report by the Chartered Management Institute.
The survey of 68,000 managers across the UK showed that the pay gap between men and women aged between 46 and 60 has widened with males on average earning 35 per cent more than their female colleagues at the executive level.
Four decades after the equal pay act was implemented, females over 40 take home on average £16,680 less than males - this rises to an average gap of £21,084 at company director level.
Across all the age ranges, the average wage gap sits at the lower £9,069, with men taking an average salary of £39,461 in comparison to womens' £30,392.
The study found that females under 19 are paid 12 per cent less than males. Between 20 and 25 this figure falls to six per cent. It was found to rise again to eight per cent between 26 and 35. Past 35 years old the pay gap widens dramatically.
Ann Francke, chief executive of the Chartered Management Institute, said: “This is all about apathy and ignorance. Companies think it is not a problem for them, so they don't do anything about it.
“Every company needs to conduct its own survey. It is pretty obvious a lot of the FTSE 350 are paying their women managers less than men for the data to turn out like this. There are very few good guys."
Francke added: “It's not right that women would have to work until almost 80 for the same pay rewards as men. We have to stamp out cultures that excuse this as the result of time out for motherhood and tackle gender bias in pay policies that put too much emphasis on time served.”
This comes after women in the digital industry were found to lag behind their male colleagues by an average of seven per cent earlier this summer, according to a salary survey from Propel.