Casey’s General Stores today announced that it had reached an agreement to buy Buchanan Energy, owner of Bucky’s Convenience Stores located mostly in Nebraska and Illinois. The all-cash transaction totals $580 million, Casey’s announced in a news release. Buchanan Energy was founded in 1980 as a family-owned and -operated business and now operates 94 retail stores and 79 dealer locations. The company also owns numerous undeveloped parcels for future store construction. The acquisition will boost Casey’s footprint to more than 2,300 stores. Ankeny-based Casey’s will finance the transaction with a combination of cash on hand, revolver capacity and bank financing. Casey’s investment represents 10.6 times Bucky’s last 12 months earnings before interest, taxes, depreciation and amortization, according to the news release. In addition, Casey’s expects to achieve $23 million in annual synergies by the third year. The transaction is expected to be completed by the end of December.