(KPL/Yonhap) The unions of Seoul Metro, the operator of subway lines 1-8, launched a slowdown protest on Monday after their wage hike negotiations fell through.

The "work-to-rule" protest by two of Seoul Metro's three unions, which account for three-quarters of all employees, caused no major disruption to commuters, though there were minor train delays at some stations.

Protest participants staged a fight for safety by securing more stop times than usual and refused to perform work that is not required by regulations.

The company's Unions 1 and 2, which have 9,036 members and 2,577 members, respectively, took the collective action demanding a pay hike of 3 percent, suspension of manpower downsizing and expansion of new hiring. But the management has stuck to a wage increase of 1.8 percent, citing financial straits.

Seoul Metro's Unions 1 and 3 have threatened to go on a general strike, beginning Dec. 12, if the management and the Seoul city government do not present a more advanced proposal, while Union 2 is reportedly discussing a general strike in the middle of this month. Union 3 has 1,988 members.

Seoul Metro said there were no major train delays on Monday morning but congestion is expected to increase particularly during peak commute hours due to the labor slowdown.

Commuters interviewed by Yonhap News Agency at busy Line 2 stations, such as Sindorim and Gangnam, said the platforms were crowded with passengers as usual during the morning rush hours.

Around 8 a.m., some train departures were delayed at Yeouido Station on Line 5, as the train stoppage time, which is usually around 30 seconds during rush hour, exceeded 50 seconds.

KPL