The 7-Eleven convenience store chain is about to get even larger. The company announced a deal to acquire 1,100 stores — primarily along the East Coast and Texas — from Sunoco in a deal valued at $3.3 billion. As part of the deal, 7-Eleven has agreed to purchase 2.2 billion gallons of gasoline from Sunoco on an annual basis. Sunoco made the deal to focus on its gasoline supply business.