UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM 8-K

CURRENT REPORT

PURSUANT TO SECTION 13 OR 15(d) OF

THE SECURITIES EXCHANGE ACT OF 1934

1515 Arapahoe Street, Tower 2, Suite 700, Denver, CO 80202

(Address of principal executive offices)

Registrant’s telephone number, including area code: 303-925-9200

Not Applicable.

(Former name or former address, if changed since last report.)

Check the appropriate box below if the Form 8-K filing is intended to simultaneously satisfy the filing obligation of the registrant under any of the following provisions (see General Instruction A.2. below):

x    Written Communications pursuant to Rule 425 under the Securities Act (17 CFR 230.425)

o     Soliciting material pursuant to Rule 14a-12 under the Exchange Act (17 CFR 240.14a-12)

o             Pre-Commencement communications pursuant to Rule 14d-2(b) under the Exchange Act (17 CFR 240.14d-2(b))

o             Pre-Commencement communications pursuant to Rule 13e-4(c) under the Exchange Act (17 CFR 240.13e-4(c))

ITEM 8.01.  Other Events.

On November 14, 2007 and November 15, 2007, Frank Semple, President and Chief Executive Officer, and Nancy Buese, Senior Vice President and Chief Financial Officer, of MarkWest Energy Partners, L.P. (the “Partnership”), will give presentations to investors in Houston and Dallas, Texas, respectively, which will  include information regarding the proposed transaction that resulted from the signing of an Agreement and Plan of Redemption and Merger on September 5, 2007, by and among MarkWest Energy Partners L.P., MarkWest Hydrocarbon, Inc. and MWEP, L.L.C.   A press release announcing this presentation is included as Exhibit 99.1.

The information included with this Current Report as Exhibit 99.2 includes graphic images or slides used in the presentation.

                This presentation utilizes the Non-GAAP financial measures of Adjusted EBITDA and Distributable Cash Flow.  We define Adjusted EBITDA as net income or loss before interest, provision for income taxes, depreciation and amortization expense, non-cash compensation expense, and non-cash unrealized derivative gain / loss.  Adjusted EBITDA is not a measure of performance calculated in accordance with GAAP, and should not be considered in isolation or as a substitute for net income, income from operations, or cash flow as reflected in our financial statements. Adjusted EBITDA is presented because such information is relevant and is used by management, industry analysts, investors, lenders, and rating agencies to assess the financial performance and operating results of our fundamental business activities. Management believes that the presentation of Adjusted EBITDA is useful to lenders and investors because of its use in the midstream natural gas industry and for master limited partnerships as an indicator of the strength and performance of our ongoing business operations. Additionally, management believes that Adjusted EBITDA provides additional and useful information to our investors for trending, analyzing, and benchmarking our operating results from period to period as compared to other companies that may have different financing and capital structures. The presentation of Adjusted EBITDA allows investors to view our performance in a manner similar to the methods used by management and provides additional insight to our operating results.  In general, we define Distributable Cash Flow as net income or loss plus (i) depreciation, amortization, and accretion expense; (ii) non-cash earnings from unconsolidated affiliates; (iii) contributions to unconsolidated affiliates net of expansion capital expenditures; (iv) non-cash compensation expense; (v) non-cash derivative activity; (vi) gains and losses on the sale of assets; and (vii) the subtraction of sustaining capital expenditures. Distributable Cash Flow is a significant liquidity metric used by our senior management to compare basic cash flows generated by us to the cash distributions we expect to pay partners. Distributable cash flow is also an important Non-GAAP financial measure for our limited partners since it serves as an indicator of our success in providing a cash return on investment. Distributable cash flow is also a quantitative standard used by the investment community with respect to publicly traded partnerships such as ours because the value of a partnership unit is in part measured by its yield (which in turn is based on the amount of cash distributions a partnership pays to a unit holder). The GAAP measure most directly comparable to Distributable Cash Flow and Adjusted EBITDA is net income.  Please see the Appendix for our calculations of Adjusted EBITDA and Distributable Cash Flow along with the appropriate reconciliations.

Cautionary Statements

                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.  Actual results could vary significantly from those expressed or implied in such statements and are subject to a number of risks and uncertainties.  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/A for the year ended December 31, 2006, as filed with the SEC.  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.”  We do not undertake any duty to update any forward-looking statement.

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                Although we believe that the expectations reflected in the forward-looking statements, specifically those including those referring to future performance, growth, cash flow, operating income, distributable cash flow (DCF), distributions, or other factors, are reasonable, these forward-looking statements are not guarantees of future performance and we can give no assurance that such expectations will prove to be correct and that projected performance or distributions may not be achieved.  Among the factors that could cause results to differ materially are those risks discussed in our Form S-1, as amended, our Annual Report on Form 10-K/A for the year ended December 31, 2006, and our Quarterly Reports on Form 10-Q, as amended, each as filed with the SEC.  You are also urged to carefully review and consider the cautionary statements and other disclosures, including those under the heading “Risk Factors,” made in those filings, which identify and discuss significant risks, uncertainties and various other factors that could cause actual results to vary significantly from those expressed or implied in the forward-looking statements.  We do not undertake any duty to update any forward-looking statement.

                On November 14, 2007, MarkWest Energy Partners and MarkWest Hydrocarbon filed a joint proxy statement/prospectus and other documents with the Securities and Exchange Commission (the “SEC”) in relation to the merger transaction announced on September 5, 2007.  Investors and security holders are urged to read these documents carefully because they contain important information regarding MarkWest Energy Partners, MarkWest Hydrocarbon, and the transaction. A definitive joint proxy statement/prospectus will be sent to security holders of MarkWest Energy Partners and MarkWest Hydrocarbon seeking their approval of the transactions contemplated by the redemption and merger agreement. Investors and security holders may obtain a free copy of the joint proxy statement/prospectus (when it is available) and other documents containing information about MarkWest Energy Partners and MarkWest Hydrocarbon, without charge, at the SEC’s website at www.sec.gov. Copies of the joint proxy statement/prospectus and the SEC filings that will be incorporated by reference in the joint proxy statement/prospectus may also be obtained free of charge by directing a request to the entities’ investor relations department at 866-858-0482, or by accessing their website at www.markwest.com.

                MarkWest Energy Partners, MarkWest Hydrocarbon, the officers and directors of the general partner of MarkWest Energy Partners, and the officers and directors of MarkWest Hydrocarbon may be deemed to be participants in the solicitation of proxies from their security holders. Information about these persons can be found in the Annual Report on Form 10-K/A for the year ended December 31, 2006, for each of MarkWest Energy Partners and MarkWest Hydrocarbon, as filed with the SEC, and additional information about such persons may be obtained from the joint proxy statement/prospectus when it becomes available.

                This document shall not constitute an offer to sell or the solicitation of an offer to buy any securities, nor shall there be any sale of securities in any jurisdiction in which such offer, solicitation, or sale would be unlawful prior to registration or qualification under the securities laws of any such jurisdiction. No offering of securities shall be made except by means of a prospectus meeting the requirements of the Securities Act of 1933, as amended.

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SIGNATURE

                Pursuant to the requirements of the Securities and Exchange Act of 1934, the Registrant has duly caused this report to be signed on its behalf by the undersigned, thereunto duly authorized.

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