Pinnacle Entertainment ( PNK) agreed to buy fellow casino owner Aztar ( AZR) for $38 a share, a price that represents a 24% premium to its closing price last Friday. The deal is worth about $1.45 billion. Pinnacle also plans to assume around $723 million of Aztar debt. "Combining Pinnacle and Aztar makes tremendous sense," said Daniel R. Lee, Pinnacle's chairman and CEO. "This transaction will enable Pinnacle to further broaden and diversify its geographic presence and cash flows, as well as generate cross-marketing synergies. We intend to create a nationwide casino network, not unlike that of some of our larger competitors." The companies expect to close the deal by the end of the year. Pinnacle owns casinos in Nevada, Louisiana, Indiana and Argentina. Aztar operates the Tropicana Casino and Resort in Atlantic City, N.J., the Tropicana Resort and Casino in Las Vegas and other properties. Shares of Aztar were up $6.62, or 21.6%, to $37.32. Pinnacle was rising $1.84, or 6.6%, to $29.80.