Coat grill rack with cooking spray; place on grill over medium-hot coals (350° to 400°).
While grill heats, position knife blade in food processor bowl; add olives and next 5 ingredients. Process until smooth; set aside.
Place fillets on rack; grill, uncovered, 5 minutes on one side. Turn fillets. Spread 2 tablespoons olive mixture over each fillet. Grill 5 additional minutes or until fish flakes easily when tested with a fork.