This is a summary. To read the whole story subscribe to BostonGlobe.com
AutoZone Inc.’s first-quarter earnings rose 7.2 percent on continued sales growth and slightly stronger margins. The nation’s largest auto parts retailer has seen its performance benefit from new stores in the United States and Mexico and a growing commercial business. The company last year began a plan to enter the Brazilian market — the fourth-largest auto market in the world. AutoZone said profit reached $218.1 million, or $6.29 a share, up from $203.5 million, or $5.41, a year earlier. Domestic same-store sales rose 0.9 percent.