Thousands of unionized workers at Samsung Electronics halted work for a second day over a pay raise Tuesday, as part of their three-day strike that marked the biggest labor action in the technology giant's 55-year history.The National Samsung Electronics Union (NSEU), the largest labor union at the world's largest memory chipmaker, launched the three-day strike Monday.It said more than 6,000 members had expressed their intention to participate in the labor action. But police estimated that around 3,000 attended the NSEU's kick-off rally Monday.Despite the strike, Samsung Electronics said there had been no disruptions to production during the first two days of labor action.Since January, the two sides have held several rounds of talks but have been unable to narrow their differences over the wage increase rate, vacation system and bonuses.The union warned that it would stage another five-day strike, starting July 15, if no progress is made during the current strike.As of Monday, the NSEU had repor ted a total membership of 30,000, accounting for approximately 24 percent of Samsung Electronics' total workforce of about 125,000.Source: Yonhap News Agency