The acquisition consideration included about $1bn of cash and the issuance of 19.95 million unregistered MarkWest Class B units to EMG.
MarkWest chairman, president and CEO Frank Semple said the Liberty joint venture has been successful in leveraging its first-mover advantage to become the largest provider of world-class midstream infrastructure critical to the development of the liquids-rich area of the Marcellus shale.
MarkWest and EMG are also forming a new Utica shale midstream joint venture to develop natural gas processing and NGL fractionation, transportation and marketing infrastructure in eastern Ohio beginning in 2012.
