CVS Caremark Corp. today completed its purchase of Longs Drug Stores Corp. for $2.7 billion, making it the largest drug store operator in California and Hawai'i.

The acquisition gives the Woonsocket, R.I.-based company 521 retail drug stores in Nevada, Arizona, California and Hawai'i, as well as Longs pharmacy benefits management service, Rx America.

"We look forward to working with our new Longs colleagues and to serving the millions of loyal customers who shop Longs stores," said Tom Ryan, CVS Caremark chairman, president and chief executive officer in a press statement.

"With the closing now behind us, we are focused on realizing the many benefits of this combination, which accelerates our expansion into key growth markets and strengthens our position as the nation's leading pharmacy services company."