Members of the Samsung Electronics workers' union shout slogans at a general strike held in front of Samsung Electronics' Hwaseong plant in Hwaseong, Gyeonggi Province, on Monday. (Yonhap)

Unionized workers of Samsung Electronics launched their first-ever strike Monday, demanding higher pay and warning of potential further action if the country's largest conglomerate does not meet their demands.

The National Samsung Electronics Union, the nation's biggest labor union with over 30,000 members which make up some 25 percent of the workforce, said it kicked off the strike starting with a rally at 11:00 a.m. in front of the main entrance of the company's facility in Hwaseong, Gyeonggi Province. The strike is scheduled to last through Wednesday.

The union said that 6,540 members participated in the general strike, of which 5,211 workers are reportedly in semiconductor facilities, manufacturing and development. The total number of union members was tallied to 36,657 as of 11 a.m., exceeding the 30,000 threshold for the first time, the union said.

Since January, several rounds of negotiations have taken place but both sides have remained at an impasse over the wage increase rate, vacation system and bonuses.

After securing the right to strike when the National Labor Relations Commission decided to suspend mediation and have the members of the union vote for and against the strike, the union declared a collective action for the first time on May 29th.

The union had previously demanded a higher wage increase for all members, fulfillment of the promise of paid leave and improvement of the standard for "Overall Performance Incentive" based on Economic Value Added, a financial metric estimating a firm's economic profit as well as compensation for wage losses caused by the strike.

"The company did not accept all of our demands during the two weeks of post-adjustment talks after June 13," said the union, claiming that "the company's post-adjustment plan does not consider workers' equal relationship and still treats laborers like expendable resources for the company."

"We are holding the company accountable for all of this through a general strike," it said, adding, "The company is solely responsible for all business losses incurred as a result of this strike."

As there were no production disruptions as feared with last month's collective action when union members coordinated annual leave to effectively stage a mass walkout, it is widely believed that this week's strike is unlikely to impact business activity.

The union said it is open to a second strike for five days from next Monday if the negotiations do not progress during this strike.

By Choi Jeong-yoon (jychoi@heraldcorp.com)