Autozone ( AZO) reported a spike in quarterly earnings on Tuesday after the closing bell. The retailer of auto parts posted a net income of $126 million in its third quarter, compared with $102.3 million last year. Its earnings per share increased to $1.30 from 96 cents. Sales grew to $1.29 billion from $1.22 billion in the year-earlier period. Same-store sales, or sales of domestic companies that have been open for more than a year, increased 2.8%. "Not only have we continued to add valued local commercial customers, we have added valued chain accounts," said Steve Odland, Autozone's chairman, president and chief executive, in a statement.