AutoZone Inc. (AZO), the largest U.S. auto parts retail chain, Wednesday said quarterly earnings slipped 1.3 percent, hurt by spending to improve store appearance and train employees, sending shares down almost 7 percent.

Net income fell to $206.6 million for the fourth quarter that ended Aug. 27, from $209.4 million a year earlier. Earnings per share rose to $2.66 from $2.53 due to share repurchases, the company said.

Analysts, on average, expected Memphis, Tenn.-based AutoZone to earn $2.83 per share, according to Reuters Estimates.

Total sales rose to 2.5 percent from a year earlier to $1.882 billion, AutoZone said. It had 3,592 stores in the United States and 81 in Mexico at the end of the quarter.

Sales at domestic stores open at least one year, or same-store sales, fell 1 percent in the quarter, the company said.

In New York Stock Exchange (search) trading, AutoZone shares fell 6.71 percent, or $6.06 to $84.21.