MarkWest Energy Partners, L.P. (NYSE: MWE) and MarkWest Liberty Ethane Pipeline, L.L.C. (“MarkWest Liberty”), collectively “MarkWest,” has extended the binding open season for the previously announced Liberty Ethane Pipeline until 5:00 p.m. Mountain Time on Friday, December 13, 2013. Subject to the outcome of the binding open season and all of the necessary regulatory authorizations, the Liberty Ethane Pipeline will transport purity ethane from Majorsville, Pennsylvania, to Houston, Pennsylvania. From there, shippers will have direct access to multiple, major ethane takeaway projects including Mariner West, Mariner East, and ATEX. The Liberty Ethane Pipeline is expected to become operational in the fourth quarter of 2013. The binding open season will allow interested parties to make volume commitments and execute long-term transportation contracts with MarkWest Liberty for transportation on the Liberty Ethane Pipeline. Shippers electing to make long-term volume commitments to MarkWest Liberty will be eligible to receive priority transportation service at a premium transportation rate for their committed volumes. Parties interested in participating in the open season and shipping on the Liberty Ethane Pipeline should contact Joshua Hallenbeck, Vice President of Finance and Treasurer at (866) 858-0482 or firstname.lastname@example.org. Information on the Liberty Ethane Pipeline and the binding open season can also be found on MarkWest’s website at: http://www.markwest.com/operations/ferc-pipelines/liberty-ethane-pipeline/. MarkWest Energy Partners, L.P. is a master limited partnership engaged in the gathering, processing and transportation of natural gas; the gathering, transportation, fractionation, storage and marketing of natural gas liquids; and the gathering and transportation of crude oil. MarkWest has a leading presence in many unconventional gas plays including the Marcellus Shale, Utica Shale, Huron/Berea Shale, Haynesville Shale, Woodford Shale and Granite Wash formation. This press release includes “forward-looking statements.” All statements other than statements of historical facts included or incorporated herein may constitute forward-looking statements. Actual results could vary significantly from those expressed or implied in such statements and are subject to a number of risks and uncertainties. Although MarkWest believes that the expectations reflected in the forward-looking statements are reasonable, MarkWest can give no assurance that such expectations will prove to be correct. The forward-looking statements involve risks and uncertainties that affect operations, financial performance, and other factors as discussed in filings with the Securities and Exchange Commission (SEC). Among the factors that could cause results to differ materially are those risks discussed in the periodic reports filed with the SEC, including MarkWest’s Annual Report on Form 10-K for the year ended December 31, 2012 and our Quarterly Report on Form 10-Q for the quarter ended September 30, 2013. You are urged to carefully review and consider the cautionary statements and other disclosures made in those filings, specifically those under the heading “Risk Factors.” MarkWest does not undertake any duty to update any forward-looking statement except as required by law.