Standard&Poor's said today that AutoZone Inc.'s (BBB+/Negative/A-2) approval of the repurchase of up to an additional $300 million shares of common stock has no immediate impact on the company's credit rating or outlook. This increase brings AutoZone's total share repurchase authorization to $2 billion, of which $1.66 billion has been utilized. The rating assumes that AutoZone will continue to repurchase shares. However, to maintain the rating, the company will need to manage this share repurchase activity so that it can reduce debt levels to improve its leverage and cash flow coverage ratios.