Metro’s largest union is seeking court help to enforce binding arbitration that called on the transit agency to give its bus and train operators 3 percent wage increases.

An arbitration panel last week settled a contract dispute by calling on Metro to give the union’s 7,700 employees a 3 percent raise each year over the next three years. But Metro officials immediately said they planned to appeal the arbitrators’ decision, arguing they could not afford to pay $96 million in raises during such tight economic times.