MarkWest Energy Partners Announces Acquisition of Keystone Midstream Services for $512M

MarkWest Energy Partners, L.P. (MarkWest) MWE today announced that it is acquiring 100% of the ownership interests of Keystone Midstream Services, LLC (Keystone), for consideration of $512 million. The transaction is expected to close during the second quarter of 2012. Keystone is owned by Stonehenge Energy Resources, LP, and affiliates of Rex Energy Corporation (Rex Energy) REXX and Sumitomo Corporation (Sumitomo). Keystone's existing assets are located in Butler County, Pennsylvania and include two cryogenic gas processing plants totaling 90 million cubic feet per day (MMcfd) of capacity, a gas gathering system and associated field compression. Rex Energy and Sumitomo have dedicated an 895 square mile area to MarkWest. To date they have jointly leased 68,400 highly prospective acres in Butler County, an acreage position that continues to grow. MarkWest will gather and process the rich gas and fractionate the NGLs under long-term fee-based agreements.