MEMPHIS, Tenn., May 21, 2013 (GLOBE NEWSWIRE) -- AutoZone, Inc. (NYSE:AZO) today reported net sales of $2.2 billion for its third quarter (12 weeks) ended May 4, 2013, an increase of 4.5% from the third quarter of fiscal 2012 (12 weeks). Domestic same store sales, or sales for stores open at least one year, decreased 0.1% for the quarter. Net income for the quarter increased $17.0 million, or 6.8%, over the same period last year to $265.6 million, while diluted earnings increased 15.8% to $7.27 per share from $6.28 per share in the year-ago quarter. For the quarter, gross profit, as a percentage of sales, was 51.8% (versus 51.6% for last year's quarter). The increase in gross margin was primarily driven by lower acquisition costs, partially offset by the inclusion of AutoAnything (39 bps). Operating expenses, as a percentage of sales, were 31.1% (versus 31.4% last year). The improvement in operating expenses, as a percentage of sales, was primarily due to net gains on disposal of certain assets (18 bps) and lower incentive compensation. Under its share repurchase program, AutoZone repurchased 833 thousand shares of its common stock for $325 million during the third quarter, at an average price of $390 per share. At quarter end, the Company had $278 million remaining under its current share repurchase authorization. The Company's inventory increased 6.3% over the same period last year, driven by an increase in store count and continued strategic investments in hard parts assortment. Net inventory, defined as merchandise inventories less accounts payable per store was a negative $63 thousand versus negative $48 thousand last year. "We are pleased to report our twenty-seventh consecutive quarter of double digit earnings per share growth. Our organization executed our game plan and delivered another quarter of solid performance. While sales results for the quarter finished below our expectations, we were pleased to see noticeable improvements in our performance during the final four weeks of the quarter, specifically in our more recently challenged Northeastern and Midwestern markets," said Bill Rhodes, Chairman, President and Chief Executive Officer. "I would like to again thank and congratulate our entire team of 70,000+ AutoZoners for their efforts to deliver strong earnings per share and return on invested capital results in the third quarter. We believe our ongoing efforts to improve our inventory assortment and accelerate its deployment will have meaningful impacts on results for upcoming quarters. We remain committed to our disciplined approach of growing operating earnings while efficiently utilizing our capital."