DENVER—January 11, 2011—MarkWest Energy Partners, L.P. (NYSE: MWE) announced
today that it priced a public offering of 3,000,000 common units at $41.20 per common unit.
MarkWest intends to use the net proceeds from the offering, after deducting underwriting discounts,
commissions and offering expenses, of approximately $120.1 million, as well as any proceeds from
the exercise of the underwriter’s over-allotment option, to partially fund its ongoing capital
expenditure program, including a portion of the costs associated with the previously announced
acquisition of assets from EQT Gathering, LLC if such transaction is completed. The Partnership
has granted the underwriter a 30-day option to purchase a maximum of 450,000 additional common
units to cover over-allotments, if any.
Morgan Stanley is acting as sole book-running manager for the offering. The 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 underwriter as follows:
Attn: Prospectus Dept.
180 Varick Street, 2nd Floor
New York, New York 10014
Toll-Free: (866) 718-1649
An electronic copy of the preliminary prospectus supplement and the accompanying base
prospectus is available from the Securities and Exchange Commission's (SEC) web site at
http://www.sec.gov. The common units are being offered pursuant to an effective shelf registration
statement that the Partnership previously filed with the SEC.
This press release shall not constitute an offer to sell or the solicitation of an offer to buy nor
shall there be any sale of these securities in any state in which such offer, solicitation, or sale would
be unlawful prior to registration or qualification under the securities laws of such state.
MarkWest Energy Partners, L.P. is a master limited partnership engaged in the gathering, transportation, and processing of
natural gas; the transportation, fractionation, marketing, and storage of natural gas liquids; and the gathering and
transportation of crude oil. MarkWest has extensive natural gas gathering, processing, and transmission operations in the
southwest, Gulf Coast, and northeast regions of the United States, including the Marcellus Shale, and is the largest natural
gas processor in the Appalachian region.
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. 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, 2009, and Quarterly Report on Form
10-Q for the quarter ended September 30, 2010. 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
MarkWest Energy Partners, L.P.
Frank Semple, 866-858-0482
Chairman, President & CEO
Nancy Buese, 866-858-0482
Senior VP and CFO
Dan Campbell, 866-858-0482
VP of Finance & Treasurer