Under the deal, Chesapeake will make a cash tender offer to acquire all outstanding shares of Bronco’s common stock at a price of $11 per share.

The transaction has been approved by the boards of directors of both companies.

Bronco currently owns 22 drilling rigs primarily operating in the Williston and Anadarko basins, including the three that are under contract with Chesapeake.

Following the closing of the transaction, Bronco’s 22 rigs will be integrated into Chesapeake’s wholly owned subsidiary, Nomac Drilling.

Chesapeake said that the acquisition will satisfy the vast majority of its anticipated rig investment needs through 2012.