Exhibit 99.1

MarkWest Energy Partners, L.P.	Contact:	Frank Semple, President & CEO
155 Inverness Drive West, Suite 200		James Ivey, CFO
Englewood, CO 80112-5000		Andy Schroeder, VP Finance & Treasurer
(800) 730-8388	Phone:	(303) 290-8700
(303) 290-8700	E-mail:	investorrelations@markwest.com
(303) 290-8769 Fax	Website:	www.markwest.com

MarkWest Energy Partners, L.P. Announces Completion of Private Placement

DENVER—November 10, 2005—MarkWest Energy Partners, L.P. (AMEX: MWE), announced that on November 9, 2005 it completed a private placement of 1,644,065 common units. The units were issued at a purchase price of $44.21 per unit, raising approximately $74 million including the general partner’s contribution. MarkWest also entered into a registration rights agreement with the investors in the private placement requiring MarkWest to file with the SEC a registration statement covering the common units issued by April 10, 2006. The proceeds of this private placement will be used to repay a portion of the funds borrowed under the Partnership’s credit facility and term loan facility used to finance the Javelina acquisition on November 1, 2005.

The securities offered in the private placement have not been registered under the Securities Act of 1933, as amended, (the “Securities Act”), or any state securities laws, and unless so registered, the securities may not be offered or sold in the United States except pursuant to an exemption from, or in a transaction not subject to, the registration requirements of the Securities Act and applicable state securities laws. This announcement shall not constitute an offer to sell or a solicitation of an offer to buy any of these securities.

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MarkWest Energy Partners, L.P. is a publicly traded master limited partnership with a solid core of midstream assets and a growing core of gas transmission assets. It is the largest processor of natural gas in the Northeast and is the largest gas gatherer of natural gas in the prolific Carthage field in east Texas. It also has a growing number of other gas gathering and intrastate gas transmission assets in the Southwest, primarily in Texas and Oklahoma.

This press release includes “forward-looking statements” within the meaning of Section 27A of the Securities Act of 1933, as amended, and Section 21E of the Securities Exchange Act of 1934, as amended. All statements other than statements of historical facts included or incorporated herein may constitute forward-looking statements. Although we believe that the expectations reflected in the forward-looking statements are reasonable, we can give no assurance that such expectations will prove to be correct. The forward-looking statements involve risks and uncertainties that affect our operations, financial performance and other factors as discussed in our filings with the Securities and Exchange Commission. Among the factors that could cause results to differ materially are those risks discussed in our Form 10-K for the year ended December 31, 2003, and our Forms 10-Q, as filed with the SEC.