Standard&Poor's Ratings Services said today that AutoZone Inc.'s (BBB+/Positive/A-2) announcement that it has increased its share repurchase authorization by $500 million has no immediate impact on the rating and outlook. Standard&Poor's had previously factored additional share repurchase activity into its rating and outlook on the company. As AutoZone continues to achieve positive same-store sales and improve operating efficiencies, this share repurchase activity is expected to be managed so as not to significantly impact credit protection measures.