Concho agrees to pay $9.5 billion in stock for RSP Permian

Concho Resources Inc. says it's buying shale-drilling energy producer RSP Permian Inc. for about $9.5 billion in stock, sending RSP shares up more than 15 percent.

Concho said Tuesday that the combined company will have the biggest drilling operation in the energy-rich Permian Basin of Texas and New Mexico, with 27 rigs spread over 640,000 acres.

The deal, if approved by RSP shareholders, will immediately increase Concho's earnings per share, according to the company.

But a Wood Mackenzie analyst says Concho is paying a rich premium of 29 percent and will be challenged to meet its $2 billion goal for boosting RSP's efficiency.

RSP shares rose $6.08 to close at $45, while Concho shares fell $13.75, or 8.8 percent, to $143.25.