Unionized office workers at SK hynix Inc., the world's second-largest memory chip maker, have agreed on a 5.7 percent wage hike with the company, industry sources said Wednesday.Some 78.6 percent of 539 representatives from SK hynix office workers' union voted in favor of this year's tentative wage deal between the company and the labor union, according to the sources.Last week, the company and the union had tentatively reached an agreement on a 5.7 percent pay raise, along with an increase in medical payments and other benefits.The new wage increase marks a slight rise from last year's 4.5 percent.Meanwhile, a separate labor union representing SK hynix's manufacturing workers rejected a similar tentative wage deal earlier this week.The company said it will continue working toward an agreement with the manufacturing workers' union.Source: Yonhap News Agency