Seoul: Unionized workers of Kakao Corp., South Korea's well-known messenger app operator, took a day off en masse on Monday in a sign of protest amid a continued gridlock in wage negotiations.

According to Yonhap News Agency, in their second collective action, unionized members staged what they called a "Log-out Day" by taking simultaneous annual leave. Approximately 2,100 workers from five units of Kakao, including its headquarters, Kakao Pay, and Kakao Enterprise, participated in the protest, as reported by the labor union.

Wage talks between Kakao's labor union and management have been at a standstill since May after the two sides failed to reach an agreement on performance-based incentives. The union is reportedly demanding that the company pay around 13 to 14 percent of operating profit as bonuses. However, the management has rejected such demands, arguing that they would impose too much burden on the company.

On June 10, workers staged their first-ever strike, with about 1,500 union members walking out from their jobs for four hours and rallying near the company's headquarters in Pangyo, south of Seoul. Industry watchers are closely monitoring the latest industrial action from Kakao's union to see if it could cause disruptions to the company's key services, such as the popular messenger app KakaoTalk.

Kakao's management has stated it plans to continue negotiations with the union while remaining on standby to ensure stable service operations.