South Korean female workers were paid on average two-thirds of the wages of their male counterparts in the first half of 2022, data showed Wednesday.

The average monthly salary of female workers during the cited period came to 2.2 million won ($1,600), which stood at 65 percent that of male workers' 3.39 million won, according to data gathered by the Korea Confederation of Trade Unions' research institute.

The fact that a greater proportion of women than men are underpaid, with a monthly salary less than 1.66 million won -- two-thirds of Koreans' median salary -- contributes to this trend. Nearly 30 percent of women in Korea were categorized as underpaid in the first half of 2022, standing in contrast to the 9.9 percent of men who are.

The data also indicated that 43 percent of female employees are hired as temporary workers -- a higher proportion than the 30 percent of men who are temporary employees. Moreover, the average number of years of employment for women came to 4.81, shorter than that of men at 6.92 years.

These discrepancies stem from the structural problem of gender discrimination in the hiring process, according to the Korea Confederation of Trade Unions. The umbrella labor union held a demonstration at around 3 p.m. Wednesday in Daehangno, central Seoul, calling on the government to address and close the gender gap in the workplace.

The findings came from data on 21.5 million paid workers, including 11.8 million men and 9.7 million women.

Almost two-thirds of female employees were employed as office clerks, caregivers, cashiers, sanitation workers, cooks, social workers, production workers, school teachers or nurses, among others.

Except for office clerks, nurses and teachers, these jobs offer monthly salaries of less than the average for all paid workers, 2.86 million won, and the gender gap in salaries tended to remain wide within the same job categories.

The findings also resonate with the Global Gender Gap Index 2022 by the World Economic Forum. Korea ranked 115th out of 146 countries surveyed in terms of the gap in economic participation and opportunities between men and women.

Korea's gender wage gap was the worst of all 38 member countries of the Organization for Economic Cooperation and Development as of 2021, according to the December 2022 estimate. In the glass-ceiling index by The Economist, Korea ranked last in terms of the role and influence of women in the workplace, out of the 29 countries surveyed.

The gender gap in average pay comes despite the fact that Korean firms in principle must provide equal employment opportunities for both genders, as well as provide equal pay for equal-value work.

The Yoon Suk Yeol administration pledged to make it mandatory for companies in Korea to disclose data related to hiring, employment and retirement by gender. In January, the Ministry of Employment and Labor laid out plans to have state-run institutions carry out such gender-based data disclosures beginning in the second half of 2023.