Rock-Tenn Co. will acquire the paperboard packaging business of Gulf States Paper Corp. for $540 million. The company will use $50 million of cash on hand and finance the rest of the transaction from a bank facility led by Wachovia Capital Markets, SunTrust Capital Markets and Banc of America Securities. Steven Voorhees, executive v.p. and cfo, said the facility would consist of a term loan and a revolver.