Activision Blizzard Inc. Chief Executive Bobby Kotick sent a letter to employees Friday, after a majority of quality assurance (QA) employees at subsidiary Raven Software chose to unionize. Kotick said the videogame maker will engage in “good faith negotiations” with the Communications Workers of America representing Raven Software employees, to enter into a collective bargaining agreement. “We begin this process after major investments in our QA team members over the past couple years, including significantly increasing starting pay for QA specialists and converting over 1,100 U.S.-based temporary and contingent QA workers to full-time positions,” Kotick wrote in the letter. “This conversion is providing access to comprehensive company benefits for QA employees and their eligible dependents.” Activision’s stock, which slipped 0.4% in premarket trading Friday, has rallied 15.4% year to date through Thursday, while the S&P 500 has dropped 15.7%.

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