Employees believe ageism, not sexism, is the most common form of discrimination at work, according to research by Lee Hecht Harrison Penna, the business management consultants.
One in five professionals said they experienced discrimination during the promotion process and 39 per cent believed it was because of their age.
While just 26 per cent cited sexism as reason for inequality, the survey revealed that HR managers are more focused on tackling sexism and not ageism.
The study canvassed the views of just over 2,000 UK employees and 100 HR managers, with 94 per cent of HR professionals saying promotion processes at their organisations were fair.
This compares to 29 per cent of respondents, who believed the promotion process at their company was unfair.
Workers who said promotion processes were biased were most likely to attribute the issue to a lack of guidance on how to climb the ranks.
More women reported feeling they had not been giving sufficient career guidance, with 40 per cent citing this as a problem compared to 26 per cent of men.
Meanwhile, 65 per cent of HR professionals believed promoting diversity leads to an improved workforce. However, 51 per cent said they support it because it is expected within today’s society and 74 per cent of employees said they would consider leaving a company if it appeared to lack diversity among its workforce.
Nicola Sullivan, senior director at Lee Hecht Harrison Penna, said: “There is a clear disconnect between the positive action HR professionals believe they are taking and how this is perceived by employees.
“To create a promotion process seen as fairer and more inclusive by its employees, HR professionals and senior management need to develop a unique solution tailored to the nature of both the organisation and staff.”