Korea has the most unfriendly working conditions among the member countries of the Organization for Economic Cooperation and Development, with the longest working hours and the biggest gap between male and female salaries, according to an OECD report released Wednesday.

Using data from 2005, the "Policies for Balancing Work and Family" report found that 77 percent of Korean women workers toil more than 40 hours a week, the highest rate among 30 OECD member nations. The OECD average was 49 percent. In the U.S. 66 percent of women put in more than 40 hours a week at work. The figure in Japan was 48 percent while for Italy and Sweden it was 44 percent and 40 percent, respectively. Korea also ranked first in the number of male workers who put in more than 40 hours at their jobs, with 87 percent, but the difference between Korea's proportion and that of the U.S. (84 percent) and Japan (80 percent) was not so wide.

The report also showed that Korea women get paid 40 percent less than what their male counterparts get, more than double the OECD average wage gap of 18.3 percent. Korean women are discouraged from finding jobs by the fact that a third of women workers are irregular and only eight percent of them hold managerial positions, the report said.

Korea is the only OECD member where the employment rate for women with college degrees or above is lower than that for women with high school diplomas or less. Despite high rates of college enrollment among women, only 57 percent of female college graduates are employed compared to 59 percent of women with high school diplomas or lower.

In the U.S., Australia, Germany, and Britain, the percentage of women with college degrees or above who join the workforce is 20 percent higher than those with less education.