MarkWest Energy Prices $1B Offering Senior Notes

MarkWest Energy Partners, L.P.

(the "Partnership") and its subsidiary MarkWest Energy Finance Corporation announced today that they have priced at par an offering of $1,000,000,000 in aggregate principal amount of 4.5% senior unsecured notes due 2023 (the "Notes"). The offering of the Notes is expected to settle on January 10, 2013, subject to customary closing conditions. Barclays, BofA Merrill Lynch, Citigroup, Goldman, Sachs & Co., J.P. Morgan, Morgan Stanley, Natixis, RBC Capital Markets, SunTrust Robinson Humphrey, UBS Investment Bank, US Bancorp, and Wells Fargo Securities are acting as joint book-running managers for the Notes offering. The Notes offering is being made only by means of a prospectus supplement and accompanying base prospectus. A copy of the prospectus supplement and accompanying base prospectus associated with this offering may be obtained from the underwriters as follows: