Members of the Kakao labor union hold a rally at KakaoBank's headquarters in Seongnam, Gyeonggi Province, July 21, hours before unionized workers at KakaoBank announced a one-day strike set for July 31. Yonhap

Unionized workers at KakaoBank are set to stage what would be the first strike at a Korean internet-only bank on Friday, putting the spotlight on labor relations across the country's digital banking sector, industry officials said Monday.

The walkout follows seven months of wage and collective bargaining talks that began in January but ended without an agreement.

The union said 95 percent of participating members voted in favor of a one-day walkout. Instead of holding rallies, employees plan to use their annual leave to join the strike.

Ahead of the strike, the union on Monday said more than half of the total employees at the bank joined the group, noting that this reflected growing employee dissatisfaction with management's approach to negotiations and the compensation system.