The United Auto Workers said more than 600 of its members walked off the job early Thursday at GE Aerospace’s jet-engine plant in Evendale, Ohio, and a nearby distribution hub in Erlanger, Kentucky, after talks on a new labor contract broke down. UAW President Shawn Fain said picketing will continue until the union secures an agreement that addresses pay, healthcare and retirement benefits. GE Aerospace said it remains committed to reaching a deal that keeps its operations running. Separately, the union declared that workers at BlueOval SK, Ford Motor’s battery joint venture with South Korea’s SK On in Kentucky, voted in favor of UAW representation. The union contends the outcome should stand despite 41 challenged ballots that it argues were improperly cast. Certification of the vote rests with the National Labor Relations Board; Ford has yet to comment. The organizing push underscores the UAW’s strategy to expand its footprint in electric-vehicle manufacturing after last year’s auto-industry strikes.