Mining giant BHP Billiton has announced the finalisation of its US$12.1 billion acquisition deal to purchase Houston-based Petrohawk Energy Corp.


BHP announced that all conditions to the closing tender had been made by BHP Billiton Petroleum (North America), with the company paying US$38.75 per share for the Petrohawk’s 239.9 million shares.


The deal has been finalised in little under a month, with BHP planning to expand rapidly in the US energy market.


“The acquisition of Petrohawk is consistent with our well defined, upstream, Tier 1 strategy and provides us with even greater exposure to the world’s largest energy market, while also broadening our geographic and customer spread.,” BHP Billiton CEO, Marius Kloppers, said


BHP Billiton has cited Petrohawk’s substantial natural gas assets as key to its acquisition strategy, saying that three world-class onshore natural gas and liquids rich shale assets were key to the deal.


Petrohawk’s assets cover approximately 1,000,000 net acres in Texas and Louisiana, with estimated 2011 net production of approximately 950 million cubic feet equivalent per day or 158 thousand barrels of oil equivalent per day.


Following the merger, Petrohawk shares will be delisted and will cease to trade on the New York Stock Exchange.


BHP’s acquisition comes as the company recently launched a $10 billion  share buyback bid on the back of its record profits, with the company recording its highest profit in its history after posting a first-half net profit of $10.6 billion, representing a 71 per cent jump in profits.