The gender wage gap in Germany is even higher than the European average of 18 percent, with men earning an average of 23.8 percent more than women. In the 27 European Union member countries, only women in Estonia, the Czech Republic, Austria and the Netherlands fared worse. ´

"This is unacceptable," EU Commissioner Viviane Reding told the German daily Die Welt.

"Germany is one of the most economically developed countries and should lead by example, instead of lagging behind."

On Friday, Commission President Jose Manuel Barosso and Justice Commissioner Reding presented a 'Charter for Women,' which outlines plans to advance women's equality throughout Europe.

"Only by achieving real equality can we boost growth in Europe," said President Barroso.

On average, women in Europe earn almost one fifth (18 percent) less than their male counterparts, according to the statistical office of the European Commission.

"This difference has hardly shrunk in the past 15 years," said Viviane Reding in Brussels on Friday.

Wage discrepancy is not just a gender equality issue, Reding stressed, but an economic one as well. An elimination of wage differentials could increase the German GDP by 30 percent, she told the daily Die Welt.

No simple answer

The pay disparity between men and women could be due to multiple factors, said Claudia Finke of the Federal Bureau of Statistics.

"It may be differences in education, the comparatively high number of women who work part-time, or the fact that women traditionally enter lower-paying fields," Finke told Deutsche Welle.

In Germany in particular, a large number of women work only part-time. According to the Federal Office of Statistics, 69 percent of employed mothers worked part-time in 2009. Ten years ago, it was only 53 percent.

Old boys' club

Not everyone believes that career choices are responsible for pay disparities. Myriam van Varenbergh, the secretary of the European Women's Lawyers' Association, said much of the gender wage gap is due to the way salaries are negotiated.

"It's because it's always men who are around the table at the moment of negotiations... and they are not aware of the problem," van Varenbergh told Deutsche Welle.

Still, says van Varenbergh, women have to take more responsibility for speaking up to themselves.

"Women are not asking as the first question, 'What will be my salary?' so employers have the feeling they can give less."

More work ahead

Van Varenbergh said the EU was on the right track by setting the agenda to encourage people to talk about the issue. She added that in countries where the gap was smaller, it was largely because women were more aware of the problem.

EU President Barroso has made women's rights a key platform, pushing member states to appoint women to the EU's ruling body. Currently, nine of the EU's 27 commissioners are women.

Author: Sarah Harman

Editor: Susan Houlton