The largest labor union at Samsung Electronics has decided to effectively end its weekslong strike and instructed its members to return to work by Monday, after wage negotiations with management fell through.

The National Samsung Electronics Union(NSEU) made the announcement through its YouTube channel on Thursday, saying it will transition into a long-term fight of partial "guerilla strikes" and work-to-rule to minimize members' wage losses.

The union and management held the latest round of wage talks for three days from Monday, without striking an agreement.

The NSEU, representing about 24 percent of the workforce at Samsung Electronics, is demanding a five-point-six-percent basic pay raise, in contrast to the management's offer of a five-point-one-percent wage hike.

Earlier in the day, the union staged a rally in front of Samsung Electronics Chairman Lee Jae-yong's residence in Seoul's Yongsan District, urging Lee to lead efforts to resolve the labor dispute.