Mix Marinade Mix, oil, orange peel and juice in small bowl. Reserve 2 tablespoons marinade for brushing. Place chicken in large resealable plastic bag or glass dish. Add remaining marinade; turn to coat well.
Refrigerate 15 minutes or longer for extra flavor. Remove chicken from marinade. Discard any remaining marinade.
Grill chicken over medium-high heat 6 to 7 minutes per side or until cooked through, turning occasionally and brushing with reserved marinade. Grill orange slices 30 seconds per side. Serve chicken with grilled orange slices.