Despite the celebration this week of International Women's Day, which calls attention to the economic, social and political achievements of women around the world, more evidence is emerging that there's still much work not being done.

A study by the World Economic Forum released Monday shows leading companies around the world are not doing enough to achieve gender equality.

In terms of the highest percentage of female employees at all levels among those companies that responded to the survey, the US comes out on top at 52%, followed by Spain (48%), Canada (46%) and Finland (44%).

"The idea that most corporations have become gender-balanced or women-friendly is still a myth," said Saadia Zahidi, co-author of the report and head of the Forum's Women Leaders and Gender Parity Programme.

According to the report, those countries who had the lowest percentage of female employees include India (23%), Japan (24%), Turkey (26%) and Austria (29%).

At the industry level, the findings of the survey confirm that the services sector employs the greatest percentage of women employees, reads a press release on the World Economic Forum’s official website.

Within this sector, the financial services and insurance (60%), professional services (56%) and media and entertainment (42%) industries employ the greatest percentage of women.

The sectors that display the lowest percentage of women in the 20 economies are automotive (18%), mining (18%) and agriculture (21%).

The Gender Gap Report 2010, the first of its kind, is based on a survey of 600 of the heads of Human Resources at the world’s largest employers in 20 countries, benchmarking them against gender equality policies.