MEMPHIS, Tenn. ( TheStreet) -- AutoZone's ( AZO) second-quarter earnings turned out better than expected as the company opened new stores and sales increased. Net income for the quarter increased by 6.4% year over year to $123.3 million, while earnings per share increased 21.2% to $2.46. AutoZone said operating expenses for the quarter were negatively impacted by higher pension expense, but partially offset by a favorable credit card class action settlement. A survey of Thomson Reuters analysts arrived at an earnings estimate of $2.35 a share on revenue of $1.49 billion. AutoZone reported second-quarter net sales of $1.5 billion, up 4%. Domestic same-store sales increased 1%. During the period, the company opened 24 new stores in the U.S. and nine new stores in Mexico. AutoZone also repurchased 565,000 common shares for $88 million during the second quarter, at an average price of $155 a share. -- Reported by Andrea Tse in New York Follow TheStreet.com on Twitter and become a fan on Facebook.