Women in Europe may be better educated or work harder than men, but they are paid much less, according to the International Labour Organisation.
The gender pay gap in Europe ranges from about 100 euros (79 pounds) to 700 euros per month, the ILO report suggested.
In the UK, women earn about 28% less than men on average, the UN body found.
In all the countries studied around the world, a proportion of the pay gap is unexplained, implying discrimination, it said.
“The actual gap varies from about 4 per cent to 36 per cent across all of the 38 countries we looked at,” ILO economist Kristen Sobeck was quoted as saying by the BBC.
In Europe in 2010, the bottom-earning 10% of women workers earned about 100 euros per month less than the bottom 10% of men.
And the top 10 per cent of high-earning women earned close to 700 euros per month less than the top 10% of men.
The ILO looked at education, experience, seniority, work sector, location and work intensity. It found that in about half of the countries studied around the world women had a stronger or better combination of those characteristics, yet were paid substantially less than men.
“For example, in the case of Sweden, what we see is that the overall gap is about 4%, but when you look at the characteristics of women and what they would be paid otherwise, the gap would turn the other way, and women would actually earn about 12% more than men,” Sobeck said.
In the UK, about one-third of the pay gap can be explained by men having attributes such as more experience or more seniority, but there is still “a huge gap” that Sobeck said could be due to discrimination.
The ILO recommended a number of ways to overcome the difference in pay between men and women, including wage policies and equality legislation, the report said.