BHP Billiton's Tender Offer to Acquire Petrohawk Energy Corporation Completed

BHP Billiton

announced today that all conditions to the closing of the tender offer by BHP Billiton Limited, BHP Billiton Petroleum (North America) Inc. and North America Holdings II Inc., to acquire all outstanding shares of common stock of Petrohawk Energy Corporation

for US$38.75 per Petrohawk share net to the seller in cash, without interest, less any applicable withholding taxes, have been satisfied. The depositary for the tender offer has advised that, as of the expiration of the Offer at 12:00 midnight, New York City time, at the end of Friday, 19 August 2011, approximately 293.9 million Petrohawk shares had been validly tendered and not withdrawn pursuant to the Offer, including approximately 36.0 million Petrohawk shares tendered by guaranteed delivery, which tendered shares represent approximately 97.4 percent of the outstanding shares of Petrohawk. BHP Billiton has accepted for payment, and expects to promptly pay for, all shares validly tendered and not withdrawn on or prior to the expiration of the Offer. As the final step of the acquisition process and following payment for all shares validly tendered and not withdrawn on or prior to the expiration of the Offer, BHP Billiton expects to effect a short-form merger under Delaware law as promptly as practicable. At the effective time of the merger, each share issued and outstanding immediately prior to the effective time (other than shares then owned by BHP Billiton, Petrohawk or any of their wholly owned subsidiaries (in each case other than on behalf of third parties) and shares that are held by any stockholders who properly demand appraisal in connection with the merger) will cease to be issued and outstanding and will be converted into the right to receive an amount in cash equal to the Offer price of US$38.75, without interest, less any applicable withholding taxes. Petrohawk will be the surviving corporation in the merger and will become an indirect wholly owned subsidiary of BHP Billiton. Following the merger, Petrohawk shares will be delisted and will cease to trade on the New York Stock Exchange.