SC 13E3

As filed with the Securities and Exchange Commission on November 14, 2007

Registration No. 333-147370

SCHEDULE 13E-3

(RULE 13e-100)

TRANSACTION STATEMENT UNDER SECTION 13(e) OF THE SECURITIES

EXCHANGE ACT OF 1934 AND RULE 13E-3 THEREUNDER

UNITED STATES
SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

RULE 13e-3 TRANSACTION STATEMENT UNDER SECTION 13(e)
OF THE SECURITIES EXCHANGE ACT OF 1934

MARKWEST HYDROCARBON, INC.

(Name of the Issuer)

MARKWEST ENERGY PARTNERS, L.P.

MARKWEST HYDROCARBON, INC.

MARKWEST ENERGY GP, L.L.C.

(Names of Persons Filing Statement)

COMMON STOCK, PAR VALUE $.01 PER SHARE

(Title of Class of Securities)

570762104
(CUSIP Number of Class of Securities)

Andrew L. Schroeder	C. Corwin Bromley	C. Corwin Bromley
MarkWest Energy Partners, L.P.	MarkWest Hydrocarbon, Inc.	MarkWest Energy GP, L.L.C.
1515 Arapahoe Street	1515 Arapahoe Street	1515 Arapahoe Street
Tower 2, Suite 700	Tower 2, Suite 700	Tower 2, Suite 700
Denver, Colorado 80202	Denver, Colorado 80202	Denver, Colorado 80202
(303) 925-9200	(303) 925-9200	(303) 925-9200

(Name, Address, and Telephone Numbers of Person Authorized to Receive

Notices and Communications on Behalf of the Persons Filing Statement)

COPIES TO:

Michael J. Swidler	George A. Hagerty
Vinson & Elkins L.L.P.	Hogan & Hartson LLP
666 Fifth Avenue	One Tabor Center, Suite 1500
26th Floor	1200 Seventeenth Street
New York, New York 10103	Denver, Colorado 80202
(212) 237-0000	(303) 899-7300

This statement is filed in connection with (check the appropriate box):

a.	x	The filing of solicitation materials or an information statement subject to Regulation 14A (§§240.14a-1 through 240.14b-2), Regulation 14C (§§240.14c-1 through 240.14c-101) or Rule 13e-3(c) (§240.13e-3(c)) under the Securities Exchange Act of 1934 (“the Act”).
b.	x	The filing of a registration statement under the Securities Act of 1933.
c.	o	A tender offer.
d.	o	None of the above.

Check the following box if the soliciting materials or information statement referred to in checking box (a) are preliminary copies: x

Calculation of Filing Fee

Transaction valuation*	Amount of filing fee**
$738,910,406	$22,685

*Calculated solely for the purpose of determining the filing fee.  The filing fee was calculated based on the sum of (1) an aggregate cash payment of $240,525,840 for the proposed redemption of 12,026,292 shares of MarkWest Hydrocarbon, Inc.’s common stock, and (2) the proposed maximum aggregate offering price for 15,453,785 common units of MarkWest Energy Partners, L.P. to be issued in connection with the merger of $498,384,566 (the sum of (1) and (2), the “Transaction Valuation”).

**  The amount of the filing fee, calculated in accordance with Exchange Act Rule 0-11(c)(1), was calculated by multiplying the Transaction value by 0.00003070.

xCheck the box if any part of the fee is offset as provided by §240.0-11(a)(2) and identify the filing with which the offsetting fee was previously paid.  Identify the previous filing by registration statement number, or the Form or Schedule and the date of its filing.

(1)Amount Previously Paid: $15,301

(2)Form or Registration No.: Form S-4

(3)Filing Party: MarkWest Energy Partners, L.P.

(4)Date Filed: November 14, 2007

Table of Contents

		Page
Introduction		1
Item 1	Summary Term Sheet	1
Item 2	Subject Company Information	1
Item 3	Identity and Background of Filing Person	2
Item 4	Terms of the Transaction	3
Item 5	Past Contacts, Transactions, Negotiations and Agreements	3
Item 6	Purposes of the Transaction and Plans or Proposals	4
Item 7	Purposes, Alternatives, Reasons and Effects	4
Item 8	Fairness of the Transaction	5
Item 9	Reports, Opinions, Appraisals and Negotiations	5
Item 10	Source and Amounts of Funds and Other Consideration	6
Item 11	Interest in Securities of the Subject Company	6
Item 12	The Solicitation or Recommendation	7
Item 13	Financial Statements	7
Item 14	Persons/Assets, Retained, Employed, Compensated or Used	7
Item 15	Additional information	8
Item 16	Exhibits	8

Introduction

                This Rule 13e-3 Transaction Statement on Schedule 13E-3 (this “Schedule”) is being filed by (i) MarkWest Hydrocarbon, Inc., a Delaware corporation (the “Corporation”) and the issuer of the common stock which is the subject of the Rule 13e-3 transaction, (ii) MarkWest Energy Partners, L.P., a Delaware limited partnership  (the “Partnership”), and (iii) MarkWest Energy GP, L.L.C. (the “General Partner”).  This Schedule relates to the Agreement and Plan of Redemption and Merger, dated as of September 5, 2007, by and among the Partnership, the Corporation and MWEP, L.L.C. (the “Redemption and Merger Agreement”).

                Concurrently with the filing of this Schedule, the Partnership is filing with the Securities and Exchange Commission a joint proxy statement and prospectus (the “Joint Proxy Statement/Prospectus”) under Regulation 14A of the Securities Exchange Act of 1934, as amended (the “Exchange Act”), and under Rule 145 and Section 6 of the Securities Act of 1933, as amended (the “Securities Act”), relating to (i) the special meetings of unitholders of the Partnership and stockholders of the Corporation at which the unitholders of the Partnership and stockholders of the Corporation will consider and vote upon, among other things, a proposal to approve and adopt the Redemption and Merger Agreement and authorize the redemption and merger transaction and related actions contemplated thereby, and (ii) the issuance by the Partnership of common units representing limited partner interests in connection with the merger.  A copy of the Joint Proxy Statement/Prospectus is attached hereto as Exhibit (a)(3) and a copy of the Redemption and Merger Agreement is attached as Annex A to the Joint Proxy Statement/Prospectus.  All references in this Schedule to Items numbered 1001 to 1016 are references to Items contained in Regulation M-A under the Exchange Act.

                The cross references below are being supplied pursuant to General Instruction G to Schedule 13E-3 and show the location in the Joint Proxy Statement/Prospectus of the information required to be included in response to the items of Schedule 13E-3. The information contained in the Joint Proxy Statement/Prospectus, including all appendices thereto and documents incorporated by reference therein, is hereby expressly incorporated herein by reference.  As of the date hereof, the Joint Proxy Statement/Prospectus is in preliminary form and is subject to completion.  Capitalized terms used but not defined in this Schedule shall have the meanings given to them in the Joint Proxy Statement/Prospectus.

Item 1.    Summary Term Sheet.

Item 1001.

The information set forth in the Joint Proxy Statement/Prospectus under the following captions is incorporated by reference pursuant to General Instruction F to Schedule 13E-3 “Questions and Answers about the Redemption and Merger” and “Summary”.

Item 2.    Subject Company Information.

Item 1002.

(a)Name and Address.  The information regarding the parties’ names and addresses set forth under the caption “Important Note about This Joint Proxy Statement/Prospectus” of the Joint Proxy Statement/Prospectus is incorporated by reference pursuant to General Instruction F to Schedule 13E-3.

(b)Securities.  The information set forth under the captions “Summary — Information about the Meetings and Voting,” “Where You Can Find More Information — The Partnership Filings with the SEC” and “Where You Can Find More Information — The Corporation Filings with the SEC” of the Joint Proxy Statement/Prospectus is incorporated by reference pursuant to General Instruction F to Schedule 13E-3.

(c)Trading Market and Price.  The information set forth under the caption “Market Prices and Distribution/Dividend Information” of the Joint Proxy Statement/Prospectus is incorporated by reference pursuant to General Instruction F to Schedule 13E-3.

(d)Dividends.  The information set forth under the caption “Market Prices and Distribution/Dividend Information” of the Joint Proxy Statement/Prospectus is incorporated by reference pursuant to General Instruction F to Schedule 13E-3.

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(e)Prior Public Offerings.  The information set forth under the captions “Where You Can Find More Information — The Partnership Filings with the SEC” and “Where You Can Find More Information — The Corporation Filings with the SEC” is incorporated by reference pursuant to General Instruction F to Schedule 13E-3.

(f)Prior Stock Purchases.  The information set forth under the captions “Where You Can Find More Information — The Partnership Filings with the SEC” and “Where You Can Find More Information — The Corporation Filings with the SEC” is incorporated by reference pursuant to General Instruction F to Schedule 13E-3.

Item 3.    Identity and Background of Filing Person.

Item 1003.

(a)Name and Address.  The information regarding the filing persons and related persons pursuant to General Instruction C to Schedule 13E-3 set forth under the captions “Important Note about This Joint Proxy Statement/Prospectus,” “Directors and Officers of the General Partner Following the Redemption and Merger,” “Interests of Certain Persons in the Redemption and Merger,” “Where You Can Find More Information — The Partnership Filings with the SEC” and “Where You Can Find More Information — The Corporation Filings with the SEC” of the Joint Proxy Statement/Prospectus is incorporated by reference pursuant to General Instruction F to Schedule 13E-3.  The name, business address and telephone number of the General Partner are as follows:

MarkWest Energy GP, L.L.C.

1515 Arapahoe Street

Tower 2, Suite 700

Denver, Colorado 80202

(303) 925-9200

(b)Business and Background of Entities.  The information set forth under the caption “The Merger Parties,” “Where You Can Find More Information — The Partnership Filings with the SEC” and “Where You Can Find More Information — The Corporation Filings with the SEC” of the Joint Proxy Statement/Prospectus is incorporated by reference pursuant to General Instruction F to Schedule 13E-3.  The General Partner is a Delaware limited liability company formed by the Corporation on January 24, 2002.  The General Partner was formed to serve as general partner of the Partnership and govern operations of the Partnership.  Unless stated otherwise herein or in documents incorporated by reference, none of the filing persons have been (i) convicted in a criminal proceeding during the past five years (excluding traffic violations or similar misdemeanors), or (ii) a party to any judicial or administrative proceeding during the past five years (except for matters that were dismissed without sanction or settlement) that resulted in a judgment, decree or final order enjoining the person from future violations of, or prohibiting activities subject to, federal or state securities laws, or a finding of any violation of federal or state securities laws.

(c)Business and Background of Natural Persons.  The information set forth under the captions “The Merger Parties,” “Directors and Officers of the General Partner Following the Redemption and Merger,” “Interests of Certain Persons in the Redemption and Merger — Interests of the Corporation’s Directors and Executive Officers in the Redemption and Merger,” “Where You Can Find More Information — The Partnership Filings with the SEC” and “— The Corporation Filings with the SEC” of the Joint Proxy Statement/Prospectus is incorporated by reference pursuant to General Instruction F to Schedule 13E-3.  Unless stated otherwise herein or in documents incorporated by reference, all natural persons specified in General Instruction C to Schedule 13E-3 (i) are U.S. citizens, (ii) have not been convicted in a criminal proceeding during the past five years (excluding traffic violations or similar misdemeanors) and (iii) have not been a party to any judicial or administrative proceeding during the past five years (except for matters that were dismissed without sanction or settlement) that resulted in a judgment, decree or final order enjoining the person from future violations of, or prohibiting activities subject to, federal or state securities laws, or a finding of any violation of federal or state securities laws.

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Item 4.    Terms of the Transaction.

Item 1004.

(a)Material Terms.  The information set forth under the captions “Information about the Meetings and Voting,” “The Proposed Redemption and Merger,” “The Redemption and Merger Agreement,” “Material Federal Income Tax Consequences of the Redemption and Merger,” “Federal Income Taxation of the Partnership and Its Unitholders” and “Comparison of the Partnership Unitholder Rights and the Corporation Stockholder Rights” of the Joint Proxy Statement/Prospectus is incorporated by reference pursuant to General Instruction F to Schedule 13E-3.

(c)Different Terms.  The merger will dilute the ownership position of the current unitholders of the Partnership.  The information set forth under the captions “The Proposed Redemption and Merger,” “Risk Factors,” “The Redemption and Merger Agreement” and “Interests of Certain Persons in the Redemption and Merger” of the Joint Proxy Statement/Prospectus is incorporated by reference pursuant to General Instruction F to Schedule 13E-3.

(d)Appraisal Rights.  The information set forth under the caption “The Proposed Redemption and Merger — Appraisal Rights” of the Joint Proxy Statement/Prospectus is incorporated by reference pursuant to General Instruction F to Schedule 13E-3.

(e)Provisions for Unaffiliated Security Holders.  With respect to granting unaffiliated security holders access to the files of the Corporation or the Partnership, the information set forth under the caption “Where You Can Find More Information” of the Joint Proxy Statement/Prospectus is incorporated by reference pursuant to General Instruction F to Schedule 13E-3.

(f)Eligibility for Listing or Trading.  The information set forth under the captions “The Proposed Redemption and Merger — Restrictions on Sales of Common Units Received in the Redemption and Merger” and “The Proposed Redemption and Merger — Listing of Common Units; Delisting and Deregistration of Common Stock of the Corporation” of the Joint Proxy Statement/Prospectus is incorporated by reference pursuant to General Instruction F to Schedule 13E-3.

Item 5.    Past Contacts, Transactions, Negotiations and Agreements.

Item 1005.

(a)Transactions.  The information set forth under the captions “Summary — Relationship of the Parties,” “Special Factors — Background of the Redemption and Merger,” “The Merger Parties,” “The Proposed Redemption and Merger,” “Where You Can Find More Information — The Partnership Filings with the SEC” and “Where You Can Find More Information — The Corporation Filings with the SEC” of the Joint Proxy Statement/Prospectus is incorporated by reference pursuant to General Instruction F to Schedule 13E-3.

(b)Significant Corporate Events.  The information set forth under the captions “The Proposed Redemption and Merger,” “Special Factors — Background of the Redemption and Merger,” “Where You Can Find More Information — The Partnership Filings with the SEC” and “Where You Can Find More Information — The Corporation Filings with the SEC” of the Joint Proxy Statement/Prospectus is incorporated by reference pursuant to General Instruction F to Schedule 13E-3.

(c)Negotiations or Contacts.  The information set forth under the captions “The Proposed Redemption and Merger,” “Special Factors — Background of the Redemption and Merger,” “— Financial Projections Provided to the Partnership’s and the Corporation’s Financial Advisors,” “Where You Can Find More Information — The Partnership Filings with the SEC” and “Where You Can Find More Information — The Corporation Filings with the SEC” of the Joint Proxy Statement/Prospectus is incorporated by reference pursuant to General Instruction F to Schedule 13E-3.

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(e)Agreements Involving the Subject Company’s Securities.  The information set forth under the captions “The Proposed Redemption and Merger — Transactions Related to the Redemption and Merger,” “The Proposed Redemption and Merger — General,” “Special Factors — Background of the Redemption and Merger,” “Interests of Certain Persons in the Redemption and Merger,” “Where You Can Find More Information — The Partnership Filings with the SEC” and “Where You Can Find More Information — The Corporation Filings with the SEC” of the Joint Proxy Statement/Prospectus is incorporated by reference pursuant to General Instruction F to Schedule 13E-3.

Item 6.    Purposes of the Transaction and Plans or Proposals.

Item 1006.

(b)Use of Securities Acquired.  The information set forth under the captions “The Proposed Redemption and Merger” and “The Redemption and Merger Agreement” of the Joint Proxy Statement/Prospectus is incorporated by reference pursuant to General Instruction F to Schedule 13E-3.

(c)(1)-(8)Plans.  The information set forth under the captions “The Proposed Redemption and Merger,” “The Redemption and Merger Agreement,” “Special Factors — Purpose and Reasons for the Redemption and Merger for the Corporation and Plans for the Corporation after the Redemption and Merger” and “Special Factors — Effects of the Redemption and Merger” of the Joint Proxy Statement/Prospectus is incorporated by reference pursuant to General Instruction F to Schedule 13E-3.

Item 7.    Purposes, Alternatives, Reasons and Effects.

Item 1013.

(a)Purposes of the Merger. The information set forth under the captions “The Proposed Redemption and Merger — General,” “Special Factors — Background of the Redemption and Merger,” “Special Factors — Recommendation of the General Partner Board and the Conflicts Committee and Their Reasons for the Redemption and Merger,” “Special Factors —Recommendation of the Corporation Board and the Deal Committee and Their Reasons for the Redemption and Merger,” “Special Factors — Purpose and Reasons for the Redemption and Merger for the Partnership,” and “Special Factors — Purpose and Reasons for the Redemption and Merger for the Corporation and Plans for the Corporation after the Redemption and Merger” and “Special Factors — Effects of the Redemption and Merger” of the Joint Proxy Statement/Prospectus is incorporated by reference pursuant to General Instruction F to Schedule 13E-3.

(b)Alternatives. The information set forth under the captions “The Proposed Redemption and Merger,” “Special Factors — Background of the Redemption and Merger,” “Special Factors — Recommendation of the General Partner Board and the Conflicts Committee and Their Reasons for the Redemption and Merger,” “Special Factors —Recommendation of the Corporation Board and the Deal Committee and Their Reasons for the Redemption and Merger,” “Special Factors — Purpose and Reasons for the Redemption and Merger for the Partnership,” “Special Factors — Purpose and Reasons for the Redemption and Merger for the Corporation and Plans for the Corporation after the Redemption and Merger” and “Special Factors — Effects of the Redemption and Merger” of the Joint Proxy Statement/Prospectus is incorporated by reference pursuant to General Instruction F to Schedule 13E-3.

(c)Reasons. The information set forth under the captions “The Proposed Redemption and Merger — Background of the Redemption and Merger,” “Special Factors — Background of the Redemption and Merger,” “Special Factors — Recommendation of the General Partner Board and the Conflicts Committee and Their Reasons for the Redemption and Merger,” “Special Factors — Recommendation of the Corporation Board and the Deal Committee and Their Reasons for the Redemption and Merger,” “Special Factors — Purpose and Reasons for the Redemption and Merger for the Partnership,” “Special Factors — Purpose and Reasons for the Redemption and Merger for the Corporation and Plans for the Corporation after the Redemption and Merger” and “Special Factors — Effects of the Redemption and Merger” of the Joint Proxy Statement/Prospectus is incorporated by reference pursuant to General Instruction F to Schedule 13E-3.

(d)Effects. The information set forth under the captions “Special Factors — Recommendation of the General Partner Board and the Conflicts Committee and Their Reasons for the Redemption and

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Merger,” “Special Factors —Recommendation of the Corporation Board and the Deal Committee and Their Reasons for the Redemption and Merger,” “Special Factors — Effects of the Redemption and Merger,” “Special Factors — Financial Projections Provided to the Partnership’s and the Corporation’s Financial Advisors,” “Transaction and Merger-Related Costs,” “Material Federal Income Tax Consequences of the Redemption and Merger” and “Comparison of the Partnership Unitholder Rights and the Corporation Stockholder Rights” of the Joint Proxy Statement/Prospectus is incorporated by reference pursuant to General Instruction F to Schedule 13E-3.

Item 8.    Fairness of the Transaction.

Item 1014.

(a)Fairness.  The information set forth under the captions “Special Factors — Recommendation of the General Partner Board and the Conflicts Committee and Their Reasons for the Redemption and Merger,” “Special Factors — Recommendation of the Corporation Board and the Deal Committee and Their Reasons for the Redemption and Merger” and “Special Factors — Position of the Partnership and the Corporation as to Fairness” of the Joint Proxy Statement/Prospectus is incorporated by reference pursuant to General Instruction F to Schedule 13E-3.

(b)Factors Considered in Determining Fairness.  The information set forth under the captions “Special Factors — Recommendation of the General Partner Board and the Conflicts Committee and Their Reasons for the Redemption and Merger,” “Special Factors — Recommendation of the Corporation Board and the Deal Committee and Their Reasons for the Redemption and Merger” and “Special Factors — Position of the Partnership and the Corporation as to Fairness” of the Joint Proxy Statement/Prospectus is incorporated by reference pursuant to General Instruction F to Schedule 13E-3.

(c)Approval of Security Holders.  The information set forth under the caption “Information about the Meetings and Voting” of the Joint Proxy Statement/Prospectus is incorporated by reference pursuant to General Instruction F to Schedule 13E-3.

(d)Unaffiliated Representative.  The information set forth under the captions “The Proposed Redemption and Merger,” “Special Factors — Background of the Redemption and Merger,” “Special Factors — Recommendation of the General Partner Board and the Conflicts Committee and Their Reasons for the Redemption and Merger” and “Special Factors —Recommendation of the Corporation Board and the Deal Committee and Their Reasons for the Redemption and Merger” of the Joint Proxy Statement/Prospectus is incorporated by reference pursuant to General Instruction F to Schedule 13E-3.

(e)Approval of Directors.  The information set forth under the caption “Special Factors — Recommendation of the Corporation Board and the Deal Committee and Their Reasons for the Redemption and Merger” of the Proxy Statement is incorporated by reference pursuant to General Instruction F to Schedule 13E-3.

(f)Other Offers.  Not applicable.

Item 9.    Reports, Opinions, Appraisals and Negotiations.

Item 1015.

(a)Report, Opinion, or Appraisal.  The information set forth under the captions “Special Factors — Opinion of Lehman Brothers Inc.—Financial Advisor to the Conflicts Committee of the General Partner Board,” “—Opinion of Merrill Lynch, Pierce, Fenner & Smith Incorporated—Financial Advisor to the Deal Committee of the Corporation Board,” “Where You Can Find More Information — The Partnership Filings with the SEC” and “— The Corporation Filings with the SEC” of the Joint Proxy Statement/Prospectus is incorporated by reference pursuant to General Instruction F to Schedule 13E-3.  With respect to the opinion of Lehman Brothers Inc. (“Lehman”), the Conflicts

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Committee of the General Partner board has also received the Lehman presentation dated September 4, 2007, and incorporated herein as Exhibit (c)(i).  With respect to the opinion of Merrill Lynch, Pierce, Fenner & Smith Incorporated (“Merrill”), the Deal Committee of the Corporation board has also received the Merrill presentation dated September 5, 2007, and incorporated herein as Exhibit (c)(ii).

(b)Preparer and Summary of the Report, Opinion, or Appraisal.  The information set forth under the captions “Special Factors — Recommendation of the General Partner Board and the Conflicts Committee and Their Reasons for the Redemption and Merger,” “Special Factors — Recommendation of the Corporation Board and the Deal Committee and Their Reasons for the Redemption and Merger,” “Special Factors — Opinion of Lehman Brothers Inc.—Financial Advisor to the Conflicts Committee of the General Partner Board,” “Special Factors — Opinion of Merrill Lynch, Pierce, Fenner & Smith Incorporated—Financial Advisor to the Deal Committee of the Corporation Board,” “Legal Matters,” “Experts,” “Where You Can Find More Information — The Partnership Filings with the SEC” and “Where You Can Find More Information — The Corporation Filings with the SEC” of the Joint Proxy Statement/Prospectus and in Annex F and Annex G to the Joint Proxy Statement/Prospectus is incorporated by reference pursuant to General Instruction F to Schedule 13E-3.

(c)Availability of Documents. The information set forth under the caption “Where You Can Find More Information” of the Joint Proxy Statement/Prospectus is incorporated by reference pursuant to General Instruction F to Schedule 13E-3.

Item 10. Source and Amounts of Funds or Other Consideration.

Item 1007.

(a)Source of Funds. The information set forth under the captions “Special Factors — Background of the Redemption and Merger,” “The Redemption and Merger Agreement” and “The Proposed Redemption and Merger — Financing” of the Joint Proxy Statement/Prospectus is incorporated by reference pursuant to General Instruction F to Schedule 13E-3.

(b)Conditions. The information set forth under the captions “Special Factors — Background of the Redemption and Merger,” “The Redemption and Merger Agreement” and “The Proposed Redemption and Merger — Financing” of the Joint Proxy Statement/Prospectus is incorporated by reference pursuant to General Instruction F to Schedule 13E-3.

(c)Expenses. The information set forth under the captions “The Redemption and Merger Agreement — Termination Fees and Expenses,” “Transaction and Merger-Related Costs,” “Where You Can Find More Information — The Partnership Filings with the SEC” and “Where You Can Find More Information — The Corporation Filings with the SEC” of the Joint Proxy Statement/Prospectus and in Annex A to the Joint Proxy Statement/Prospectus is incorporated by reference pursuant to General Instruction F to Schedule 13E-3.

(d)Borrowed Funds.  The information set forth under the caption “The Proposed Redemption and Merger — Financing” of the Joint Proxy Statement/Prospectus is incorporated by reference pursuant to General Instruction F to Schedule 13E-3.

Item 11. Interest in Securities of the Subject Company.

Item 1008.

(a)Securities Ownership. The information set forth under the captions “Interests of Certain Persons in the Redemption and Merger,” and “Where You Can Find More Information — The Corporation Filings with the SEC” of the Joint Proxy Statement/Prospectus is incorporated by reference pursuant to General Instruction F to Schedule 13E-3.

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(b)Securities Transactions.  The information set forth under the caption “The Proposed Redemption and Merger — Transactions Related to the Redemption and Merger,” “Where You Can Find More Information — The Partnership Filings with the SEC” and “Where You Can Find More Information — The Corporation Filings with the SEC” of the Joint Proxy Statement/Prospectus is incorporated by reference pursuant to General Instruction F to Schedule 13E-3.

Item 12. The Solicitation or Recommendation.

Item 1012.

(d)Intent to Tender or Vote in a Going-Private Transaction. The information set forth under the captions “Special Factors — Recommendation of the General Partner Board and the Conflicts Committee and Their Reasons for the Redemption and Merger,” “—Recommendation of the Corporation Board and the Deal Committee and Their Reasons for the Redemption and Merger,” “Interests of Certain Persons in the Redemption and Merger,” “The Proposed Redemption and Merger — Transactions Related to the Redemption and Merger,” “Information about the Meetings and Voting” and “Annex E — Voting Agreement by and among MarkWest Energy Partners, L.P., John M. Fox and MWHC Holding, Inc.” of the Joint Proxy Statement/Prospectus is incorporated by reference pursuant to General Instruction F to Schedule 13E-3.

(e)Recommendations of Others. The information set forth under the captions “Special Factors — Recommendation of the General Partner Board and the Conflicts Committee and Their Reasons for the Redemption and Merger,” “—Recommendation of the Corporation Board and the Deal Committee and Their Reasons for the Redemption and Merger,” and “Information about the Meetings and Voting” of the Joint Proxy Statement/Prospectus is incorporated by reference pursuant to General Instruction F to Schedule 13E-3.

Item 13. Financial Statements.

Item 1010.

(a)Financial Information. The information set forth under the caption “Summary Historical and Unaudited Pro Forma Combined Financial and Operating Information” of the Joint Proxy Statement/Prospectus is incorporated by reference pursuant to General Instruction F to Schedule 13E-3.  More complete financial information can be obtained by reference to the information set forth under the captions “Where You Can Find More Information — The Partnership Filings with the SEC” and “Where You Can Find More Information — The Corporation Filings with the SEC” of the Joint Proxy Statement/Prospectus, which is incorporated by reference pursuant to General Instruction F to Schedule 13E-3.

(b)Pro Forma Information.  The information set forth under the caption “Summary Historical and Unaudited Pro Forma Combined Financial and Operating Information” of the Joint Proxy Statement/Prospectus is incorporated by reference pursuant to General Instruction F to Schedule 13E-3.  More complete financial information can be obtained by reference to the information set forth under the captions “Where You Can Find More Information — The Partnership Filings with the SEC” and “Where You Can Find More Information — The Corporation Filings with the SEC” of the Joint Proxy Statement/Prospectus, which is incorporated by reference pursuant to General Instruction F to Schedule 13E-3.

Item 14. Persons/Assets, Retained, Employed, Compensated or Used.

Item 1009.

(a)Solicitations or Recommendations.  The information set forth under the captions “Questions and Answers,” “Information about the Meetings and Voting,” and “Transaction and Merger-Related Costs,” of the Joint Proxy Statement/Prospectus is incorporated by reference pursuant to General Instruction F to Schedule 13E-3.

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(b)Employees and Corporate Assets.  The information set forth under the captions “Information about the Meetings and Voting,” “The Proposed Redemption and Merger” and “The Redemption and Merger Agreement” of the Joint Proxy Statement/Prospectus and in Annex A to the Joint Proxy Statement/Prospectus is incorporated by reference pursuant to General Instruction F to Schedule 13E-3.

Item 15. Additional information.

Item 1011.

(b)           Other Material Information. None.

Item 16. Exhibits.

Item 1016.

(a)(1)	Not applicable.
(a)(2)(i)	Preliminary copy of Joint Letter to Unitholders and Stockholders from MarkWest Energy Partners, L.P., and MarkWest Hydrocarbon, Inc., incorporated by reference to the Joint Proxy Statement/Prospectus.
(a)(2)(ii)	Preliminary copy of Notice of Special Meeting of MarkWest Energy Partners, L.P. Unitholders, incorporated by reference to the Joint Proxy Statement/Prospectus.
(a)(2)(iii)	Preliminary copy of Notice of Special Meeting of Stockholders of MarkWest Hydrocarbon, Inc., incorporated by reference to the Joint Proxy Statement/Prospectus.
(a)(3)	Preliminary Joint Proxy Statement/Prospectus, incorporated by reference to Form S-4 filed by MarkWest Energy Partners, L.P., on November 14, 2007.
(a)(4)	Refer to Exhibit (a)(3), preliminary Joint Proxy Statement/Prospectus.
(a)(5)	Refer to Exhibit (a)(3), preliminary Joint Proxy Statement/Prospectus, and Annexes thereto.
(b)	Not applicable.
(c)(i)	Presentation of Lehman Brothers Inc. to the Conflicts Committee of the General Partner board on September 4, 2007.
(c)(ii)	Presentation of Merrill Lynch, Pierce, Fenner & Smith Incorporated to the Deal Committee of the Corporation board on September 5, 2007.
(c)(iii)	Refer to Exhibit (a)(3), preliminary Joint Proxy Statement/Prospectus, and Annexes thereto.
(d)	Refer to Exhibit (a)(3), preliminary Joint Proxy Statement/Prospectus, and Annexes thereto, including the Agreement and Plan of Redemption and Merger and the Voting Agreement by and among MarkWest Energy Partners, L.P., John M. Fox and MWHC Holding, Inc.
(f)	Dissenter’s rights of appraisal are described in the preliminary Joint Proxy Statement/Prospectus, which is filed herewith as Exhibit (a)(3).
(g)	Not applicable.

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SIGNATURES

After due inquiry and to the best of my knowledge and belief, I certify that the information set forth in this statement is true, complete and correct.

MARKWEST ENERGY PARTNERS, L.P.,
a Delaware limited partnership
By:	/s/ Nancy K. Buese
Name:	Nancy K. Buese
Title:	Senior Vice President and Chief Financial Officer
Date:	November 13, 2007
MARKWEST HYDROCARBON, INC.,
a Delaware corporation
By:	/s/ Nancy K. Buese
Name:	Nancy K. Buese
Title:	Senior Vice President and Chief Financial Officer
Date:	November 13, 2007
MARKWEST ENERGY GP, L.L.C.,
a Delaware limited liability company
By:	/s/ Nancy K. Buese
Name:	Nancy K. Buese
Title:	Senior Vice President and Chief Financial Officer
Date:	November 13, 2007

9

EXHIBIT INDEX

(a)(1)	Not applicable.
(a)(2)(i)	Preliminary copy of Joint Letter to Unitholders and Stockholders from MarkWest Energy Partners, L.P., and MarkWest Hydrocarbon, Inc., incorporated by reference to the Joint Proxy Statement/Prospectus.
(a)(2)(ii)	Preliminary copy of Notice of Special Meeting of MarkWest Energy Partners, L.P. Unitholders, incorporated by reference to the Joint Proxy Statement/Prospectus.
(a)(2)(iii)	Preliminary copy of Notice of Special Meeting of Stockholders of MarkWest Hydrocarbon, Inc., incorporated by reference to the Joint Proxy Statement/Prospectus.
(a)(3)	Preliminary Joint Proxy Statement/Prospectus, incorporated by reference to Form S-4 filed by MarkWest Energy Partners, L.P., on November 14, 2007.
(a)(4)	Refer to Exhibit (a)(3), preliminary Joint Proxy Statement/Prospectus.
(a)(5)	Refer to Exhibit (a)(3), preliminary Joint Proxy Statement/Prospectus, and Annexes thereto.
(b)	Not applicable.
(c)(i)	Presentation of Lehman Brothers Inc. to the Conflicts Committee of the General Partner board on September 4, 2007.
(c)(ii)	Presentation of Merrill Lynch, Pierce, Fenner & Smith Incorporated to the Deal Committee of the Corporation board on September 5, 2007.
(c)(iii)	Refer to Exhibit (a)(3), preliminary Joint Proxy Statement/Prospectus, and Annexes thereto.
(d)	Refer to Exhibit (a)(3), preliminary Joint Proxy Statement/Prospectus, and Annexes thereto, including the Agreement and Plan of Redemption and Merger and the Voting Agreement by and among MarkWest Energy Partners, L.P., John M. Fox and MWHC Holding, Inc.
(f)	Dissenter’s rights of appraisal are described in the preliminary Joint Proxy Statement/Prospectus, which is filed herewith as Exhibit (a)(3).
(g)	Not applicable.

10

EX-99.(C)(I)

Exhibit (c)(i)

The Conflicts Committee of MarkWest Energy GP, L.L.C. Project Solution Discussion Materials September 4, 2007 Confidential Presentation to:

Disclaimer The following pages contain material that was provided to the Conflicts Committee of the Board of Directors of MarkWest Energy GP, L.L.C. (the “Conflicts Committee”) by Lehman Brothers Inc. ("Lehman Brothers"). The accompanying material was compiled or prepared on a confidential basis solely for use by the Conflicts Committee and not with a view toward public disclosure under state and federal securities laws. The information contained in this material was obtained from MarkWest Energy Partners, L.P. (“MWE”), MarkWest Hydrocarbon, Inc. (“MWP”) and/or other publicly available sources, and Lehman Brothers has relied upon such information without independent verification thereof. Any estimates and projections for MWE and/or MWP and the assets associated with Project Solution contained herein have been prepared by management of MWE and/or MWP, or are based upon such estimates and projections. Furthermore, the projections contained herein may or may not be achieved and differences between projected results and those actually achieved may be material. No representation or warranty, expressed or implied, is made as to the accuracy or completeness of such information and nothing contained herein is, or shall be relied upon as, a promise or representation, whether as to the past or the future. Because this material was prepared for use in the context of a presentation to the Conflicts Committee, the material was not prepared to comply with the disclosure standards set forth under state and federal securities laws and, to the extent the material may be used by readers not as familiar with the business and affairs of MWE and/or MWP as the Conflicts Committee, neither MWE and/or MWP nor Lehman Brothers nor any of their respective legal or financial advisors or accountants takes any responsibility for the accuracy or completeness of any of the material when used by persons other than the Conflicts Committee. DRAFT

Table of Contents Agenda Introduction Transaction Overview Pro Forma Analysis Valuation Analysis _____________________________________________________________ Appendices Valuation Analysis Supplement Valuation Sensitivity Supplement Other Considerations

Introduction Lehman Brothers is pleased to meet with the Conflicts Committee of the Board of Directors of MarkWest Energy GP, L.L.C. (the “Conflicts Committee”) to discuss the proposed three-step transaction pursuant to which MarkWest Energy Partners, L.P. (“MarkWest” or “MWE”) will acquire MarkWest Hydrocarbon, Inc. (“MWP” or “Hydrocarbon”) and up to a 10.3% interest in MarkWest Energy GP, L.L.C. (“MWE GP”) owned by a group of individuals principally comprised of certain members of MWE’s management and directors (“the Insider Interest”) Step One: MarkWest will purchase 100% of the common stock of Hydrocarbon for total consideration of $741.5 million, comprised of $20.00 per MWP share in cash and 1.285 MWE common units for each MWP share, valued at $32.31 based on the 20-day volume-weighted average price of MWE common units as of August 31, 2007 (the “20-day VWAP”) The principal assets of Hydrocarbon are an 89.7% interest in MWE GP, 4,938,992 MWE common units (an approximate 13.3% LP interest in MWE) and a natural gas liquids fractionation trading and marketing business (the “NGL Business”) Step Two: MarkWest will purchase the Insider Interest for $51.6 million, comprised of $21.0 million of cash and ~0.95 million MWE common units with an aggregate value of $30.6 million based on the 20-day VWAP as of August 31, 2007 Step Three: MarkWest will exchange [22,500,000] Class A units (the “Class A Units”) for Hydrocarbon’s 89.7% interest in MWE GP (including the related incentive distribution rights) and 4,938,992 MWE common units This step is done following the previous steps and is entirely internal (Hydrocarbon is a wholly-owned subsidiary of MWE at this point) The following pages discuss, among other things, the summary terms of the transaction, the financial consequences thereof and our valuation of MarkWest and Hydrocarbon The following analysis is based on the terms of the transaction as they currently stand Lehman Brothers has been engaged to render its opinion regarding the fairness, from a financial point of view, to the MWE unitholders unaffiliated with MWE GP, of the aggregate consideration to be paid in the transaction by MWE Introduction 1

Strategic Rationale Considerations Benefits Adverse Tax Consequences Reduction in tax shield for existing MWE unitholders Ongoing tax leakage from having MWP C-Corp in MLP chain (this tax leakage exists currently at MWP) Somewhat mitigated by tax shield of interest expense at MWP Commodity Price Exposure MWP’s NGL Business will be acquired by MWE, and although hedging contracts exist, it will add an element of commodity price exposure Reduction in Management Incentives to Achieve Growth IDRs have historically been a powerful incentive to achieve expected growth LTIP added to help Potentially Confusing Structure The Class A Units held at MWP will likely have different distributions than MWE’s Common Units, potentially creating a challenging modeling exercise for investors and research analysts The Class A Units will be treated as Treasury stock and not included in units outstanding, but will be receive a taxable MWE income allocation as well as an allocation of MWE depreciation Significantly Improves Cost of Capital Elimination of the IDRs will reduce MWE’s equity cost of capital Allows MWE to be more competitive in M&A market Reduces internal hurdle rate / enhances returns for organic growth projects Provides meaningful long-term accretion to extent more aggressive acquisition strategy realized Potential Yield Compression / Multiple Expansion Driven by market expectation of higher growth potential Further adds to cost of capital improvement Distributable Cash Flow Accretion The transaction is expected to be accretive to MWE’s unitholders immediately and over the projected period Simplifies Governance and Removes Conflicts of Interest Removes disproportionate consequences, which alleviates conflict of interest issues Potential for Synergies / Cost Reductions Move from two SEC reporting entities to one SEC reporting entity Fulfills Market Expectations for a Transaction The market reacted positively (one-day price appreciation for MWE and Hydrocarbon was 4.6% and 5.1%, respectively) upon a prior statement that the companies were considering a combination Transaction Overview 2

Partnership/Company Overview Summary Information ___________________________ $61.52 is the consideration for MWP based on per share exchange rate of $20.00 in cash and 1.285 shares of MWE valued at the 20-day VWAP of $32.31 per unit. Transaction Overview 3 ($ in millions, except per unit data) Hydrocarbon MWE Standalone MWE Proposal Premium Exchange NYSE NYSE Fiscal Year End December 31 December 31 52-Week High $37.50 $64.30 NA Current Price (8/31/07) 31.88 50.29 $60.97 21.2% 52-Week Low 23.16 25.50 NA 20-Day VWAP $32.31 $51.23 $61.52 20.1% Current Annualized Distribution $2.12 $1.44 $1.44 Yield (8/31/07) 6.65% 2.86% 2.34% Capitalization Equity Value (20-day VWAP) $1,164 $606 $742 Net Debt (6/30/07) 497 (32) (32) Enterprise Value $1,660 $574 $709 Credit Ratings (Moody's / S&P) B1 / B+ NA NA Outlook (Moody's / S&P) Pos. / Stable NA NA (1) (1)

Historic Share Price Performance Transaction Overview January 2004 - today ___________________________ Source: FactSet as of August 31, 2007. 4 (8/8/07) MWE releases 2Q07 results, citing a 19% increase in distributable cash flow over last year's figure (7/25/07) MWE increases quarterly cash distribution to $0.53 per unit (4/24/07) MWE announces $135 million private placement (2/21/07) MWE announces that it will consider strategic options with MWP (1/26/07) MWE declares cash distribution of $1.00 per unit and announces two-for-one split (1/4/07) MWE announces the acquisition of Santa Fe Gathering LLC (11/1/06) MWE announces a $0.97 per unit cash distribution (8/3/06) MWE announces a cash distribution of $0.92 per unit (4/26/06) MWE announces a cash distribution of $0.87 per unit (7/3/06) MWE announces the IPO of its common units (7/11/05) AMEX approves MWE's plan of action to bring the company back into AMEX compliance (7/20/04) MWE announces its intent to acquire American Central's East Texas gathering and processing system (1/8/04) MWP completes the acquisition of Shell Pipeline (4/26/05) MWP announces that it will delay filing of its annual report; AMEX informs the company that such action will will be considered non-compliant with AMEX standards (4/12/04) MWP reveals that its free cash flow for the 12-month period ending Dec 31 was negative $37m 1/1/2004 5/28/2004 10/22/2004 3/22/2005 8/17/2005 1/13/2006 6/9/2006 11/6/2006 4/4/2007 8/31/2007 $0 $10 $20 $30 $40 $50 $60 $70 Price MarkWest Energy Partners L.P. MarkWest Hydrocarbon Inc.

MWE issues [22,500,000] Class A Units to MWP (now an MWE wholly-owned subsidiary) in exchange for MWP’s 89.7% interest in MWE GP and 4,938,992 MWE common units The Class A Units will receive income allocations from MWE based only on earnings associated with MWE’s base business, excluding MWP’s NGL Business Based upon the advice of the Conflicts Committee, Lehman Brothers has assumed that this exchange will not trigger any additional tax liability MWE purchases the Insider Interest of 10.3% in MWE GP owned by various management and directors (2) of MWE and MWP for $51.6 million The $51.6 million purchase price is comprised of $21.0 million of cash and ~0.95 million MWE common units valued at $30.6 million based on the MWE 20-day VWAP as of August 31, 2007 of $32.31 per unit Consideration approximates a mix of 40.0% cash and 60.0% equity MWE purchases 100% of the common stock of Hydrocarbon for $61.52 per share or an aggregate equity value of $741.5 million The $61.52 per share purchase price is comprised of $20.00 per share in cash(1) and 1.285 MWE common units per MWP share, worth $41.52 per share based on the 20-day VWAP of $32.31 per unit In the aggregate, MWE will pay $241.1 million in cash and issue ~15.5 million MWE common units to the MWP shareholders Represents 32.5% cash and 67.5% equity based on the 20-day VWAP Structured as a fixed exchange ratio cash election merger with applicable proration Based upon the advice of the Conflicts Committee, Lehman Brothers has assumed that the exchange of MWP shares for MWE units will not create a tax liability Purchase of the Insider Interest Restructuring Transaction Acquisition of MWP Transaction Overview The Proposed Transaction Will Consist of the Following Steps: Transaction Overview ___________________________ Structurally, the cash will be conveyed to MWP shareholders through a redemption by MWP concurrent with the closing of the transaction. Owners of the Insider Interest include Frank Semple (2.0%), John Fox (1.6%), John Mollenkopf (1.6%), Randy Nickerson (1.6%), Donald Heppermann (1.0%), Nancy Buese (0.2%), Corwin Bromley (0.1%) and others (2.2%). 5

Majority vote of the MWP shareholders (including the vote of Mr. Fox) Majority vote of the unaffiliated unitholders of MWE (those unitholders not affiliated with MWP or the MWE GP) Tax opinions from Vinson & Elkins and Hogan & Hartson The Restructuring Transaction must be completed simultaneously with closing (the acquisition of MWP is not contingent on the purchase of the Insider Interest) HSR and other customary closing conditions John Fox (Chairman of the Board of Directors of Hydrocarbon and Chairman of the Board of Directors of MWE GP) owns ~45% of the outstanding shares of MWP He has pledged to vote in favor of the proposed transaction However, he has a Fiduciary Out in the event the Special Committee of the Board of Directors of Hydrocarbon (the “Deal Committee”) changes its recommendation MWP will remain a C-Corporation held underneath MWE; therefore, any taxable income allocated to the Class A Units held by MWP will be fully taxable Combining Class A Unit taxable income allocations with the projected earnings from MWP’s NGL Business results in tax leakage at the consolidated entity In order to mitigate tax leakage, the portion of the cash proceeds issued to MWP shareholders upon the purchase of MWP by MWE will be raised through the issuance of $236.8 million of debt at MWP The interest expense associated with this debt will partially offset the taxable income generated at MWP through the NGL Business and the Class A Unit taxable income allocations Given that MWE is an MLP and a flow-through entity, its interest expense historically would not have been tax deductible Fox Support Agreement Closing Conditions Tax Transaction Terms Key Terms of the Transaction Transaction Overview 6

The transaction contains a “go-shop” provision for MWP Go-shop period of 30 days Following 30 days, a standard “no-shop” provision is adopted MWE has an indirect right to match a superior proposal due to a 4-day notification period Break-up fee of 1% during the go-shop period and 2% during the no-shop period Deal Protections Transaction Terms Key Terms of the Transaction (Continued) Transaction Overview 7

Transaction Structure Ownership Structure – Pro Forma Ownership Structure – Status Quo MWE Pro Forma Ownership Structure Public / Private 31,162,117 MWE Common Units MarkWest Energy GP, L.L.C. MarkWest Energy Partners, L.P. 36,499,909 Total Common Units 2.0% G.P. Interest and IDRs MarkWest Hydrocarbon, Inc. (1) 4,938,992 MWE Common Units 89.7% Officers / Directors (2) 398,800 MWE Common Units 5,525,909 MWP Common Stock 10.3% 13.3% L.P. Interest 1.1% L.P. Interest 83.7% L.P. Interest Public 6,475,300 MWP Common Stock 53.9% 46.1% (44.6% John Fox) ___________________________ MWP has 12,053,356 total shares outstanding as of August 31, 2007. Includes Frank Semple (2.0%), John Fox (1.6%), John Mollenkopf (1.6%), Randy Nickerson (1.6%), Donald Heppermann (1.0%), Nancy Buese (0.2%), Corwin Bromley (0.1%) and others (2.2%). NGL Business 100.0% MarkWest Operating Subsidiaries 100.0% Interest Transaction Overview 8 MWE Public / Private MWP Shareholders Officers & Directors 31,162,117 MWE Common Units 6,910,018 John Fox 1,344,946 MWE Common Units 8,578,544 other MWP 64.9% 32.3% of which 14.4% 2.8% L.P. Interest L.P. Interest by John Fox L.P. Interest MarkWest Energy GP, L.L.C. Non-Economic Interest MarkWest Energy Partners, L.P. 47,995,625 Total Common Units 22,500,000 Total Class A Units MarkWest MarkWest Hydrocarbon, Inc. Operating 22,500,000 Total Class A Units Subsidiaries $236,820,529 Debt 100.0% Interest NGL Business

Pro Forma Analysis Lehman Brothers has analyzed the impact of the proposed transactions on MWE’s distributable cash flow per L.P. unit and MWE’s credit profile Upon the advice of the Conflicts Committee, Lehman Brothers has assumed the acquisition of Hydrocarbon and the Restructuring Transaction will be tax-free Under the terms of the transaction: MWE acquires the stock of MWP for cash and MWE units with a purchase price of $61.52 per share for MWP, comprised of: $20.00 per share in cash, financed by $236.8 million in new borrowings at MWP (8.75% assumed interest rate) and the remaining cash component paid through excess cash and working capital on MWP’s balance sheet 1.285 MWE common units per share of MWP (15.5 million new MWE units issued) MWP remains a corporation and becomes a subsidiary of MWE MWE acquires the 10.3% Insider Interest for $51.6 million (comprised of $21.0 million of cash and ~0.95 million MWE common units valued at $30.6 million) Immediately following the above acquisitions, the 89.7% interest in MWE GP, 4,938,992 MWE common units held by Hydrocarbon are exchanged for [22.5] million new Class A Units issued by MWE and the 10.3% Insider Interest is dissolved The Class A Units will receive income allocations from MWE based only on earnings associated with MWE’s base business, excluding MWP’s NGL Business The Class A Units will be eligible for cash distributions based solely on distributable cash flow from MWE’s base business, excluding MWP’s NGL Business cash flow All projections were provided by management Pro Forma Assumptions Pro Forma Analysis 9

Pro Forma Analysis We have analyzed the proposed transaction with sensitivities around growth capital and commodity price assumptions Growth Capital: We have used a base growth case agreed to by the Conflicts Committee of unidentified internal growth capital expenditures incremental to MWE’s existing capital budget of $60 million in 2008, $125 million in 2009 and $150 million in 2010 and beyond. We have also analyzed a case where, as a result of the cost of capital benefits of this transaction, pro forma MWE invests an incremental $200 million of capital per year (the “Improved Acquisition Case”) Growth capital invested at 8x EBITDA, with annual maintenance capital expenditures of 4% of EBITDA Financed with 60% equity / 40% debt Equity is issued at a 6.25% distribution yield on a standalone basis and a 5.75% distribution yield on a pro forma basis Debt to finance the growth capital is issued at an 8.75% interest rate Commodity Prices: We have used three sets of commodity price assumptions, including those provided to us by management, strip prices as quoted by Bloomberg L.P. as of August 31, 2007 (the “Strip Price Case”) and a downside case with $50.00 oil and $7.00 natural gas (the “$50 / $7 Case”) Based on management guidance, we have assumed $2.5 million of annual synergies Included in both the base and pro forma projections is an assumed $50 million equity issuance at MWE in 4Q 2007 Cash proceeds used to fund identified organic capital projects in 2008 Pro Forma Assumptions (Continued) Pro Forma Analysis 10

Transaction Capitalization Financing Overview – Management Case ___________________________ Value based on 20-day VWAP of $32.31 per unit. Cash estimate provided by management as of 12/31/2007. Standalone column includes 4,938,992 MWE common units held at Hydrocarbon. Pro forma column assumes Hydrocarbon’s MWE LP interests are exchanged for MWE Class A Units and treated as Treasury stock for capitalization purposes. Sources & Uses Pro Forma Capitalization Pro Forma Analysis (3) 11 ($ in millions, except where noted) Sources Amount % Uses Amount % MWE Common Units Issued $531 66.1% Cash Proceeds $262 32.6% Debt Raised at MWP 237 29.5% MWE Units 531 66.1% Excess Cash at MWP 35 4.4% Transaction Fees / Costs 10 1.2% Total Sources $803 100.0% Total Uses $803 100.0% (1) (1) (2) ($ in millions, except where noted) Market Capitalization MWE Standalone Project Solution Adjustments MWE Pro Forma MWE 20-day VWAP $32.31 $32.31 L.P. Units Outstanding (mm) 36.5 11.5 48.0 Equity Value - L.P. $1,179 $1,551 Net Debt (6/30/07) 497 237 733 Total Enterprise Value $1,676 $2,284

Transaction Capitalization Equity Ownership Pro Forma MWE Equity Ownership – Management Case Pro Forma Analysis (1) ___________________________ Includes 327,898 MWE units (0.7%) and 6,910,018 units owned by John Fox (14.4%) for total of 7,237,916 MWE units (15.1%). (1) 12 (Shares in millions) Standalone Pro Forma Equity Classes Units % Ownership Units % Ownership Common Units - Public / Private 31.2 83.7% 31.2 64.9% Common Units - Held at MWP 4.9 13.3% - - Common Units - Officers and Directors 0.4 1.1% 1.3 2.8% Common Units - Issued to MWP Shareholders - - 15.5 32.3% Total Common L.P. Units 36.5 98.0% 48.0 100.0% Class A Units - Held at MWP - - 22.5 N/A Total L.P. Units 36.5 98.0% 70.5 100.0% General Partner Interest - MWP N/A 1.8% N/A N/A General Partner Interest - Officers and Directors N/A 0.2% N/A N/A Total G.P. Interest N/A 2.0% N/A N/A Total Equity Ownership 36.5 100.0% 70.5 100.0%

MWE Standalone Financial Projections Financial Projections Commodity Price Decks Pro Forma Analysis 13 ($s in millions, except per unit data) 2008E - 2012E 2008E - 2016E 2008E 2009E 2010E 2011E 2012E 2013E 2014E 2015E 2016E CAGR CAGR EBITDA Management Case $214.7 $237.9 $247.8 $270.7 $292.7 $310.5 $325.9 $344.2 $358.4 8.1% 6.6% Wall Street Estimates 205.7 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A Distributable Cash Flow Management Case $157.6 $172.2 $176.2 $193.9 $211.3 $225.5 $238.2 $254.3 $267.0 7.6% 6.8% Wall Street Estimates 163.7 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A DCF / L.P. Unit Management Case $2.73 $2.84 $2.77 $2.86 $2.94 $2.98 $3.00 $3.05 $3.07 1.8% 1.5% Wall Street Estimates 2.71 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A Distributions / L.P. Unit Management Case $2.43 $2.47 $2.47 $2.51 $2.57 $2.60 $2.63 $2.66 $2.67 1.5% 1.2% Wall Street Estimates 2.42 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A DCF to G.P. Interest Management Case $52.5 $58.8 $59.3 $66.5 $73.6 $79.2 $83.9 $90.5 $95.3 8.8% 7.7% Wall Street Estimates 54.2 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A Distributions to G.P. Interest Management Case $40.7 $44.0 $46.5 $51.0 $56.3 $60.5 $64.7 $69.4 $72.9 8.5% 7.6% Wall Street Estimates 39.3 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A ($s in millions, except per unit data) 2008E - 2012E 2008E - 2016E 2008E 2009E 2010E 2011E 2012E 2013E 2014E 2015E 2016E CAGR CAGR Management Case Crude Oil $73.24 $73.16 $72.48 $71.91 $71.35 $70.80 $70.25 $69.71 $69.16 (0.6%) (0.7%) Natural Gas 8.29 8.42 8.22 7.95 8.00 8.00 8.00 8.00 8.00 (0.9%) (0.4%) Strip Price Case Crude Oil $69.95 $68.64 $67.96 $67.68 $67.61 $67.61 $67.61 $67.61 $67.61 (0.8%) (0.4%) Natural Gas 7.78 8.22 8.06 7.83 7.63 7.63 7.63 7.63 7.63 (0.5%) (0.2%) 50/7 Case Crude Oil $50.00 $50.00 $50.00 $50.00 $50.00 $50.00 $50.00 $50.00 $50.00 0.0% 0.0% Natural Gas 7.00 7.00 7.00 7.00 7.00 7.00 7.00 7.00 7.00 0.0% 0.0%

Accretion / (Dilution) Analysis Accretion / (Dilution) – Base Case Accretion / (Dilution) Analysis Pro Forma Analysis 14 ($ in millions except where noted) Pro Forma Standalone Management Improved Acquisition DCF / L.P. Unit Base Case Case Case 2008E $2.73 3.6% 5.6% 2009E $2.84 4.0% 8.9% 2010E $2.77 7.6% 14.8% 2011E $2.86 11.6% 21.0% 2012E $2.94 14.1% 25.6% 2013E $2.98 16.4% 30.0% 2014E $3.00 17.4% 33.2% 2015E $3.05 18.7% 36.4% 2016E $3.07 19.6% 39.3% 2008-11 Average $2.80 6.7% 12.5% 2008-13 Average $2.85 9.5% 17.6% 2008-16 Average $2.92 12.5% 23.9% 3 Yr. CAGR ('08-'11) 1.5% 4.1% 5.8% 5 Yr. CAGR ('08-'13) 1.7% 4.1% 5.5% 8 Yr. CAGR ('08-'16) 1.5% 3.3% 4.6%

Accretion / (Dilution) Sensitivity Analysis Accretion / (Dilution) – Commodity Price Sensitivities Accretion / (Dilution) Analysis – Base Case Pro Forma Analysis 15 ($ in millions except where noted) Pro Forma Management Strip Price $50 / $7 DCF / L.P. Unit Case Case Case 2008E 3.6% 2.6% (0.4%) 2009E 4.0% 2.9% (3.0%) 2010E 7.6% 5.7% (9.9%) 2011E 11.6% 9.5% (9.3%) 2012E 14.1% 12.8% (5.2%) 2013E 16.4% 15.6% (2.1%) 2014E 17.4% 17.2% 0.0% 2015E 18.7% 18.6% 1.7% 2016E 19.6% 20.0% 3.0% 2008-11 Average 6.7% 5.2% (5.6%) 2008-13 Average 9.5% 8.2% (5.0%) 2008-16 Average 12.5% 11.7% (2.8%) 3 Yr. CAGR ('08-'11) 4.1% 3.5% (6.6%) 5 Yr. CAGR ('08-'13) 4.1% 4.2% (1.7%) 8 Yr. CAGR ('08-'16) 3.3% 3.6% (0.2%)

Pro Forma Credit Impact Credit Profile Credit Profile Analysis – Management Case Pro Forma Analysis ___________________________ Note: Assumes $50 million equity raise at MWE in Q4 2007. For illustrative purposes, assumes transaction closes at 6/30/07. (1) (1) (1) (1) 16 Management Strip Price $50 / $7 Case Case Case MWE MWE Inc. Acq. MWE MWE MWE MWE Statistics Standalone Pro Forma Case Standalone Pro Forma Standalone Pro Forma Total Debt LTM (6/30/07) $529.0 $765.9 $765.9 $529.0 $765.9 $529.0 $765.9 2007E $649.8 $886.6 $886.6 $652.7 $889.6 $655.9 $892.7 2008E $698.5 $935.3 $1,015.9 $704.9 $941.7 $708.1 $944.9 EBITDA LTM (6/30/07) $174.0 $194.0 $194.0 $174.0 $194.0 $174.0 $194.0 2007E $173.5 $189.7 $189.7 $174.2 $196.6 $172.9 $180.8 2008E $214.7 $227.8 $237.8 $213.0 $224.7 $218.3 $222.0 Credit Statistics Total Debt / EBITDA LTM (6/30/07) 3.04 x 3.95 x 3.95 x 3.04 x 3.95 x 3.04 x 3.95 x 2007E 3.75 x 4.67 x 4.67 x 3.75 x 4.53 x 3.79 x 4.94 x 2008E 3.25 x 4.11 x 4.27 x 3.31 x 4.19 x 3.24 x 4.26 x EBITDA / Interest Expense LTM (6/30/07) 4.66 x 3.34 x 3.34 x 4.66 x 3.34 x 4.66 x 3.34 x 2007E 4.78 x 3.36 x 3.36 x 4.80 x 3.49 x 4.75 x 3.20 x 2008E 3.94 x 3.04 x 3.11 x 3.89 x 2.99 x 3.95 x 2.94 x

Valuation Analysis Overview of Valuation Methodologies Lehman Brothers has performed the following valuation analyses: A valuation of MWE’s L.P. units using a comparable companies analysis and a discounted cash flow analysis These analyses are used to value the consideration being paid by MWE, as well as the L.P. units held by Hydrocarbon that are being purchased by MWE A valuation of 100% of MWE GP using a comparable companies analysis, a comparable transactions analysis and a discounted cash flow analysis A valuation of Hydrocarbon’s NGL Business using a discounted cash flow analysis Additionally, Lehman Brothers examined the impact of commodity prices on the valuation of the entities being acquired and on the consideration being offered This sensitivity was performed using discounted cash flow analyses Valuation Analysis 17

Valuation Summary Consolidated Valuation vs. Aggregate Consideration Amalgamated Methodologies (Management Commodity Case) Management Case Strip Case $50 / $7 Case Consolidated Valuation Aggregate Consideration Valuation Analysis DCF only Aggregate Consideration based on 20-day VWAP ($758 million) ___________________________ Note: Dotted boxes indicate contributed value from assuming present value of $2.5 million of synergies of $18.3 million to $27.0 million, respectively. Synergy Value $955 $944 $955 $680 18 $682 $677 $847 $928 $400 $500 $600 $700 $800 $900 $1,000 MWP Equity Value ($ mm) $388 $571 $611 $603 $597 $615 $746 $818 $917 $928 $653 $814

MWE L.P. Unit Valuation Summary (Pre-Tax) ___________________________ All MWE statistics are based on data from Wall Street Research. Note: DCF range based on low and high; comparable company range based on average; implied MWE L.P. unit value range based on average of DCF and comparable company low and high. Discounted Cash Flow Analysis Comparable Companies Analysis Valuation Analysis Base Case (Management Commodity Case) 19 Equity Value per Unit Based Discount on Perpetuty Growth Rates of: Rate 0.0% 0.5% 1.0% 9.0% $33.83 $34.84 $35.97 11.0% 27.77 28.34 28.98 13.0% 23.59 23.95 24.34 $23.59 -- $35.97 ($ in millions) Valuation MWE (1) Equity Value Parameter Statistics Relevant Yields Reference Range Distributable Cash Flow 2007E $2.60 8.0% -- 6.5% $32.55 -- $40.06 2008E 2.71 9.0% -- 7.0% 30.08 -- 38.67 Distributions LQA $2.12 7.0% -- 5.5% $30.29 -- $38.55 2007E 2.14 7.0% -- 5.0% 30.60 -- 42.83 2008E 2.42 7.5% -- 6.5% 32.22 -- 37.18 $31.15 -- $39.46 Implied MWE L.P. Unit Value Range of $27.37 - $37.71

MWE GP Valuation (Pre-Tax) Discounted Cash Flow Analysis Comparable Companies Analysis Comparable Transactions Analysis ___________________________ All MWP statistics are based on data from Wall Street Research. Comparable Companies Analysis includes $2.0 million of incremental public company G&A expenses. Assumes cash flow attributable to 100% of the G.P. interest and related IDRs. Valuation Analysis Base Case (Management Commodity Case) 20 Enterprise Value Based Discount on DCF Multiples of: Rate 20.0x 25.0x 30.0x 15.0% $661 $762 $862 16.0% 622 715 808 17.0% 586 672 758 $586 -- $862 ($ in millions) Valuation MWE Equity Value Parameter Statistics (1) Relevant Multiples Reference Range Distributable Cash Flow (After G&A) 2007E $42.4 20.0x -- 25.0x $848 -- $1,061 2008E 52.2 17.0x -- 22.0x 887 -- 1,148 Distributions (After G&A) LQA $25.5 25.0x -- 30.0x $638 -- $765 2007E 34.0 23.5x -- 28.5x 798 -- 968 2008E 37.3 18.5x -- 23.5x 691 -- 877 $772 -- $964 ($ in millions) Valuation MWE GP Equity Value Parameter Statistics (1) Relevant Multiples Reference Range Distributable Cash Flow (Before G&A) LQA $45.8 12.5x -- 16.5x $573 -- $756 2007E 44.4 12.5x -- 16.5x 555 -- 733 Distributions (Before G&A) LQA $27.5 20.0x -- 25.0x $550 -- $688 2007E 36.0 20.0x -- 25.0x 719 -- 899 $599 -- $769

NGL Business Valuation (Pre-Tax) Discounted Cash Flow Analysis – Management Case Valuation Analysis Base Projections Base Case (Management Commodity Case) ___________________________ We have assumes standalone cash SG&A expense of $4 million per management. 21 2008E 2009E 2010E 2011E 2012E 2013E 2014E 2015E 2016E CAGR EBITDA $22.1 $16.6 $20.0 $21.4 $20.0 $18.8 $17.6 $16.4 $15.2 (4.6%) SG&A (1) (4.0) (4.0) (4.0) (4.0) (4.0) (4.0) (4.0) (4.0) (4.0) Distributable Cash Flow $ 18.1 $ 12.6 $ 16.0 $ 17.4 $ 16.0 $ 14.8 $ 13.6 $ 12.4 $ 11.2 (5.9%) Equity Value based on Discount Perpetuity Growth Rate of: Rate (7.5%) (5.0%) (2.5%) 8.0% $130 $138 $149 10.0% 123 129 137 12.0% 116 121 128 $116 -- $149

G&A Calculations Discounted Cash Flow Analysis Valuation Analysis MWP Excess G&A Calculation ___________________________ We have assumes standalone cash SG&A expense of $4 million per management. 22 2008E 2009E 2010E 2011E 2012E 2013E 2014E 2015E 2016E Total G&A $20.3 $20.7 $21.1 $21.5 $22.0 $22.4 $22.9 $23.3 $23.8 Non-cash ($8.8) ($9.0) ($9.2) ($9.3) ($9.5) ($9.7) ($9.9) ($10.1) ($10.3) NGL G&A ($4.0) ($4.0) ($4.0) ($4.0) ($4.0) ($4.0) ($4.0) ($4.0) ($4.0) Total G&A $7.5 $7.7 $8.0 $8.2 $8.4 $8.7 $9.0 $9.2 $9.5 PV of Cash Flows PV of Terminal Value Based Discount per L.P. Unit on Perpetuity Growth Rate of: Equity Value Rate ('08 -'16) (1.0%) 0.0% 1.0% (1.0%) 0.0% 1.0% 10.0% $50.2 $36.2 $40.2 $45.1 $86.3 $90.4 $95.3 12.0% $46.7 $26.0 $28.5 $31.4 $72.7 $75.2 $78.1 14.0% $43.6 $19.2 $20.8 $22.6 $62.8 $64.4 $66.2 $63 -- $95

MWP Tax Calculations Discounted Cash Flow Analysis Valuation Analysis Projections of the NGL Business Base Case (Management Commodity Case) ___________________________ We have assumes standalone cash SG&A expense of $4 million per management. 23 NGL Business Tax Calculation 2008E 2009E 2010E 2011E 2012E 2013E 2014E 2015E 2016E CAGR Revenue $205.3 $198.6 $202.1 $203.2 $201.7 $200.2 $198.7 $200.2 $198.8 (0.4%) Operating Expenses (183.2) (182.1) (182.1) (181.7) (181.7) (181.4) (181.2) (183.9) (183.6) SG&A (20.3) (20.7) (21.1) (21.5) (22.0) (22.4) (22.9) (23.3) (23.8) MLP Equity Income 29.8 34.0 34.6 38.8 43.4 46.3 49.1 52.5 54.9 EBITDA $31.6 $29.9 $33.4 $38.7 $41.4 $42.7 $43.8 $45.5 $46.3 4.9% Taxable Income Interest Income 2.7 3.3 3.9 4.6 5.3 6.0 6.6 7.3 7.9 DDD&A and Other (0.8) (0.5) (0.5) (0.5) (0.5) (0.5) (0.5) (0.5) (0.5) Less MLP Equity Income (29.8) (34.0) (34.6) (38.8) (43.4) (46.3) (49.1) (52.5) (54.9) Plus Allocated MLP Taxable Income 44.9 49.1 50.9 53.9 58.1 60.9 63.3 66.2 68.4 Plus Non-Deductible SG&A 8.8 9.0 9.2 9.3 9.5 9.7 9.9 10.1 10.3 Pre-Tax Income $57.4 $56.7 $62.3 $67.2 $70.4 $72.4 $74.0 $76.1 $77.4 3.8% Tax Rate 37.7% 37.7% 37.7% 37.7% 37.7% 37.7% 37.7% 37.7% 37.7% NGL Business Taxes Paid ($21.6) ($21.4) ($23.5) ($25.4) ($26.6) ($27.3) ($27.9) ($28.7) ($29.2) 3.8% MWP New Debt Tax Shield Calculation 2008E 2009E 2010E 2011E 2012E 2013E 2014E 2015E 2016E CAGR Interest on Acquisition Debt ($20.7) ($20.7) ($20.7) ($20.7) ($20.7) ($20.7) ($20.7) ($20.7) ($20.7) NM Tax Rate 37.7% 37.7% 37.7% 37.7% 37.7% 37.7% 37.7% 37.7% 37.7% MWP New Debt Tax Shield $7.8 $7.8 $7.8 $7.8 $7.8 $7.8 $7.8 $7.8 $7.8 NM PV of Cash Flows PV of Terminal Value Based Discount per L.P. Unit on Perpetuity Growth Rate of: Equity Value Tax Shield Rate ('08 -'16) (1.0%) 0.0% 1.0% (1.0%) 0.0% 1.0% Equity Value 10.0% $ (151) $ (112) $ (124) $ (139) $ (263) $ (275) $ (290) $ 78 12.0% (141) (80) (88) (97) (221) (228) (237) $ 65 14.0% (131) (59) (64) (70) (190) (195) (201) $ 56 $ (225) -- $ (243) $ 66 Actual Tax Impact $ (158) -- $ (177)

Valuation Summary – MWP Value of MWP Valuation Analysis Base Case (Management Commodity Case) 24 ($ in millions, except per unit data) Units Range MWE Common Units Equity Value per Unit Owned Pre-Tax Value DCF Analysis $23.59 -- $35.97 4.9 $117 -- $178 Comparable Companies Analysis $31.15 -- $39.46 4.9 $154 -- $195 MWE Common Unit Value Range $27.37 -- $37.71 4.9 $135 -- $186 Interest Range MWE GP Total Equity Value Owned Pre-Tax Value DCF Analysis $586 -- $862 89.7% $525 -- $774 Comparable Companies Analysis $772 -- $964 89.7% $693 -- $864 Comparable Transactions Analysis $599 -- $769 89.7% $538 -- $690 MWE GP Value Range $585 -- $776 Range NGL Marketing Business Pre-Tax Value DCF Analysis $116 -- $149 Range Excess G&A Pre-Tax Value PV of Excess G&A ($63) -- ($95) MWP Consolidated Valuation Consolidated Pre-Tax Value Range $773 -- $1,016 Less: PV of Taxes Paid at MWP ($225) -- ($243) Plus: PV of Tax Shield of New Debt at MWP 66 -- 66 Net Effect of Taxes ($158) -- ($177) Consolidated After-Tax Value Range $615 -- $839

Insider Interest Valuation Insider Interest Valuation Valuation Analysis Base Case (Management Commodity Case) 25 ($ in millions, except per unit data) Aggregate MWE GP Total Equity Value Interest Pre- and After-Tax Value DCF Analysis $586 -- $862 10.3% $60 -- $89 Comparable Companies Analysis $772 -- $964 10.3% $80 -- $99 Comparable Transactions Analysis $599 -- $769 10.3% $62 -- $79 MWE GP Value Range $67 -- $89

Valuation Summary Consolidated Valuation Valuation Analysis Aggregate Consideration Paid ___________________________ Adjusted for 1.285 exchange ratio. Consolidated Valuation vs. Consideration (Management Commodity Case) 26 MWP Consolidated Valuation Value Range ($mm) Consolidated Pre-Tax Valuation Range $773 -- $1,016 Less Tax Impact (158) (177) Consolidated After-Tax Value Range $615 -- $839 Insider Interest Valuation Pre-Tax / After-Tax Value Range $67 -- $89 Total Consolidated Valuation Range $682 -- $928 Consideration Paid to MWP Value per Unit Units Value Range ($mm) Cash $20.00 -- $20.00 12.05 $241 -- $241 MWE Units $27.37 -- $37.71 15.49 424 -- 584 Total $665 -- $825 Consideration Paid to Insiders Value per Unit Units Value Range ($mm) Cash N/A $21 -- $21 MWE Units $27.37 -- $37.71 0.95 26 -- 36 Total $47 -- $57 Excess Cash and Working Capital ($35) -- ($35) Aggregate Consideration Paid Range $677 -- $847 (1)

Commodity Price Sensitivity – Discounted Cash Flow Valuation Analysis 27 Management Strip Case 50/7 Case Case Case Case MWE Common Units $117 -- $178 $116 -- $176 $103 -- $156 MWE GP (89.7%) 525 -- 774 520 -- 767 444 -- 646 NGL Marketing 116 -- 149 114 -- 152 (77) -- (48) Excess G&A (63) -- (95) (63) -- (95) (63) -- (95) Consolidated Pre-Tax $695 -- $1,005 $686 -- $1,000 $407 -- $658 Taxes (158) -- (177) (142) -- (159) (70) -- (80) Total MWP Valuation $537 -- $828 $543 -- $840 $337 -- $578 Insider Interest 60 -- 89 60 -- 88 51 -- 74 Total Aggregate Valuation $597 -- $917 $603 -- $928 $388 -- $653 Consideration to MWP Shareholders Cash $241 -- $241 $241 -- $241 $241 -- $241 MWE Units 365 -- 557 362 -- 553 324 -- 489 $607 -- $798 $603 -- $794 $565 -- $730 Consideration to Insider Interest Cash $21 -- $21 $21 -- $21 $21 -- $21 MWE Units 22 -- 34 22 -- 34 20 -- 30 $43 -- $55 $43 -- $55 $41 -- $51 Excess Cash and Working Capital ($35) -- ($35) ($35) -- ($35) ($35) -- ($35) Aggregate Consideration Paid $615 -- $818 $611 -- $814 $571 -- $746

Summary Valuation Analysis of MWP Premia Paid in Recent Energy Transactions(1) ___________________________ Note: Shading denotes MLP mergers. Transactions greater than $1 billion of enterprise value where the consideration was not 100% cash. Denotes Merger of Equals or disrupted stock price due to market rumours prior the announcement. These transactions are excluded from High, Mean, Median, and Low calculations. Valuation Analysis 28 Transaction Value ($mm) Premium Closed Target Acquiror Consideration Equity Enterprise 1-Day 1-Week 1-Month Pending Western Oil Sands Marathon Oil Cash & Stock $ 5,532.9 $ 6,224.1 21.8% 18.6% 28.1% Pending (2) GlobalSantaFe Transocean Cash & Stock $ 17,226.2 $ 17,300.2 0.1% 3.8% 3.3% Pending Pogo Plains Exploration Cash & Stock $ 3,556.0 $ 5,373.5 18.5% 18.0% 10.7% Pending KCS Energy Petrohowak Energy Cash & Stock 1,611.9 1,967.1 9.6% 18.8% 32.9% 1/7/2007 Houston Exploration Forest Oil Cash & Stock $ 1,500.5 $ 1,655.6 7.8% 0.3% (4.0)% 6/12/2006 Pacific Energy Partners Plains All American Pipeline Cash & Stock 1,395.3 1,984.3 10.6% 10.2% 15.4% 3/31/2006 Burlington Resources ConocoPhillips Cash & Stock 35,194.9 36,400.3 20.9% 22.8% 37.7% 1/30/2006 Vintage Petroleum Occidental Petroleum Cash & Stock 3,569.5 4,118.9 33.4% 29.7% 22.6% 8/10/2005 (2) Unocal Chevron Texaco Cash & Stock 17,186.0 19,898.3 (3.0)% (5.6)% (2.8)% 7/1/2005 Kaneb Services Valero LP Cash Only 518.3 1,154.1 37.9% 34.1% 31.7% 7/1/2005 Kaneb Pipe Line Partners Valero LP Stock Only 1,744.4 2,360.0 21.3% 17.8% 19.1% 6/7/2005 Magnum Hunter Resources Climarex Energy Cash & Stock 1,556.1 2,211.3 27.2% 28.9% 30.5% 5/16/2005 Patina Oil & Gas Nomble Energy Cash & Stock 3,002.0 3,610.0 18.7% 21.5% 25.5% 1/9/2005 Premcor Valero Energy Cash & Stock 6,721.4 7,726.5 25.9% 33.4% 26.5% 9/30/2004 (2) Gulfterra Enterprise Products Partners Cash & Stock 2,550.9 4,550.1 2.2% 3.7% 2.0% 9/28/2004 (2) Evergreen Resources Pioneer Natural Resources Cash & Stock 1,891.2 2,175.0 (4.0)% (7.9)% 15.4% 6/25/2004 Westport Resources Kerr-McGee Stock Only 2,600.0 3,663.7 10.7% 10.9% 13.4% 4/25/2003 (2) Ocean Energy Devon Energy Cash & Stock 3,643.3 5,280.1 3.6% 9.8% 7.0% 8/30/2002 (2) Conoco Phillips Petroleum Stock Only 15,346.0 24,783.0 (0.3)% (10.8)% (2.9)% 1/4/2002 Marine Drilling Pride International Stock Only 1,969.5 1,995.7 13.4% 16.2% 15.8% 11/20/2001 Global Marine Santa Fe International Cash & Stock 3,143.6 3,817.6 16.8% 9.5% 4.2% 11/1/2001 Louis Dreyfus Natural Gas Dominion Resources Cash & Stock 1,840.1 2,359.2 22.0% 20.9% 32.4% 9/19/2001 Tosco Phillips Petroleum Cash & Stock 7,397.8 9,268.0 34.4% 38.8% 45.0% 9/13/2001 HS Resources Kerr-McGee Cash & Stock 1,270.9 1,840.6 20.9% 36.4% 38.0% 8/2/2001 Ultramar Diamond Shamrock Valero Energy Cash & Stock 4,118.7 5,846.6 34.1% 21.1% 48.7% 8/1/2001 (2) Barrett Resources Williams Cos Cash & Stock 2,456.9 2,729.1 5.8% 10.7% 17.6% 5/8/2001 UTI Energy Patterson Energy Stock Only 1,408.5 1,463.9 8.8% 8.0% 21.5% 1/24/2001 Mitchell Energy & Development Devon Energy Cash & Stock 3,086.5 3,502.5 32.3% 31.2% 39.1% 3/6/1998 Santa Fe Pacific Pipeline Kinder Morgan Enegery Paterns Cash & Stock 1,038.0 1,350.9 31.8% 31.8% 38.6% High 37.9% 38.8% 48.7% Mean 21.8% 21.8% 26.1% Median 21.1% 21.0% 27.3% Low 7.8% 0.3% (4.0)%

Appendices

Valuation Analysis Supplement

MWE L.P. Unit Valuation Summary (Pre-Tax) Detailed Projections Valuation Analysis Supplement Base Case (Management Commodity Case) Discounted Cash Flow Analysis 29 2008E 2009E 2010E 2011E 2012E 2013E 2014E 2015E 2016E CAGR EBITDA Base $ 195.6 $ 207.3 $ 200.1 $ 204.4 $ 207.9 $ 207.2 $ 204.1 $ 203.8 $ 199.5 0.2% EBITDA from Acquisitions 3.8 15.3 32.4 51.0 69.5 88.0 106.6 125.1 143.6 37.7% EBITDA 199.4 222.6 232.5 255.4 277.4 295.2 310.6 328.9 343.1 7.0% Plus Non-Cash Phantom Stock Compensation 15.3 15.3 15.3 15.3 15.3 15.3 15.3 15.3 15.3 Base (53.5) (54.5) (56.6) (55.9) (54.6) (52.3) (49.2) (45.5) (41.1) (3.2%) From Acquisitions (1.1) (4.3) (9.1) (14.4) (19.6) (24.9) (30.1) (35.4) (40.6) 57.9% Interest Expense (54.5) (58.8) (65.7) (70.2) (74.2) (77.2) (79.3) (80.9) (81.7) 5.2% Taxes - - - - - - - - - Change in Working Capital - - - - - - - - - Growth Capex - - - - - - - - - Maintenance Capex (4.3) (6.9) (5.9) (6.5) (7.2) (7.8) (8.4) (9.0) (9.7) 10.5% Other 1.8 - - - - - - - - Distributable Cash Flow $ 157.6 $ 172.2 $ 176.2 $ 193.9 $ 211.3 $ 225.5 $ 238.2 $ 254.3 $ 267.0 6.8% DCF / L.P. Unit $ 2.73 $ 2.84 $ 2.77 $ 2.86 $ 2.94 $ 2.98 $ 3.00 $ 3.05 $ 3.07 1.5% PV of Cash Flows PV of Terminal Value Based Equity Value per Unit Based Discount per L.P. Unit on Perpetuity Growth Rate of: on Perpetuty Growth Rates of: Rate ('08 -'16) 0.0% 0.5% 1.0% 0.0% 0.5% 1.0% 9.0% $18.10 $15.72 $16.73 $17.87 $33.83 $34.84 $35.97 11.0% 16.84 10.92 11.50 12.13 27.77 28.34 28.98 13.0% 15.72 7.87 8.23 8.61 23.59 23.95 24.34 $23.59 -- $35.97

Summary of Pipeline MLP Comparables ___________________________ Source: Lehman Brothers Investment Banking. Respective MLP senior unsecured debt rating, where applicable. Otherwise, rating is for the OLP senior unsecured debt. Valuation Sensitivity Supplement Pipeline MLP Comparable Peer Group Selected Pipeline MLPs 30 ($ in millions, except per unit data) Copano DCP Duncan Martin Regency SemGroup Sunoco Targa TC Energy Midstream Energy Hiland Midstream Energy Energy Logistics Resources Pipelines Williams Median Equity Value (as of 8/31/07) $1,648.3 $1,141.8 $496.8 $848.6 $587.8 $1,883.5 $809.7 $1,906.4 $944.8 $1,424.5 $1,900.6 Net Debt 267.1 621.9 164.9 150.5 161.2 405.7 137.5 540.0 274.2 582.9 671.5 Net Market Cap. $1,915.4 $1,763.7 $661.7 $999.2 $749.0 $2,289.2 $947.2 $2,446.4 $1,219.0 $2,007.4 $2,572.1 Unit Price (as of 8/31/07) $38.99 $45.25 $23.98 $50.01 $38.33 $32.00 $30.05 $53.70 $30.00 $37.16 $44.59 Annualized Distr. $1.76 $2.12 $1.60 $2.93 $2.64 $1.52 $1.25 $3.35 $1.35 $2.62 $2.10 Valuation Metrics Disributable Cash Flow 2007E 6.58% 5.07% 6.86% 6.58% 7.79% 5.26% 4.33% 6.25% 7.06% 8.48% 5.59% 6.58% 2008E 6.95% 6.52% 7.23% 7.99% 8.66% 6.87% N/A 6.55% 8.38% 8.96% 7.53% 7.38% Distributions LQA 4.51% 4.69% 6.67% 5.86% 6.89% 4.75% 4.16% 6.24% 4.50% 7.05% 4.71% 4.75% 2007E 4.41% 4.46% 6.67% 5.84% 7.02% 4.84% N/A 6.18% 4.73% 7.14% 4.60% 5.34% 2008E 5.31% 5.90% 6.76% 6.38% 8.04% 5.68% N/A 6.35% 5.83% 7.57% 5.25% 6.13% Net Market Cap./ 2007E EBITDA 14.4 x 16.8 x 8.6 x 17.5 x 10.9 x 15.4 x NA 13.4 x 10.4 x 13.3 x 13.3 x 13.9 x 2008E EBITDA 12.5 x 13.7 x 8.2 x 13.3 x 8.8 x 13.2 x NA 12.5 x 7.2 x 12.2 x 6.8 x 12.3 x Credit Statistics Net Debt / Net Book Cap. 34.1% 65.2% 33.6% 48.2% 39.0% 43.6% 126.8% 48.3% 26.1% 38.8% 83.9% 43.6% Net Debt / Net Market Cap. 13.9% 35.3% 24.9% 15.1% 21.5% 17.7% 14.5% 22.1% 22.5% 29.0% 26.1% 22.1% Total Debt / LTM EBITDA 2.3x 5.6x 2.8x 3.5x 2.8x 3.5x 2.9x 3.3x 3.4x 3.5x 3.9x 3.4x LTM EBITDA / Int. Expense 5.1x 3.8x 5.4x 6.3x 5.9x 2.5x 7.9x 5.4x 4.3x 4.4x 3.4x 4.3x Senior Unsecured Ratings / Outlook (1) Moody's B2/Pos N/R N/R N/R N/R B2/Neg N/R Baa2/Stable N/R N/R Ba3/Stable S&P BB-/Pos N/R N/R N/R N/R N/R N/R BBB/Stable N/R N/R BB+/Pos

MWE GP Valuation (Pre-Tax) Discounted Cash Flow Analysis Valuation Analysis Supplement Detailed Projections Base Case (Management Commodity Case) 31 2008E 2009E 2010E 2011E 2012E 2013E 2014E 2015E 2016E CAGR EBITDA Base $ 195.6 $ 207.3 $ 200.1 $ 204.4 $ 207.9 $ 207.2 $ 204.1 $ 203.8 $ 199.5 0.2% EBITDA from Acquisitions 3.8 15.3 32.4 51.0 69.5 88.0 106.6 125.1 143.6 37.7% EBITDA 199.4 222.6 232.5 255.4 277.4 295.2 310.6 328.9 343.1 7.0% Plus Non-Cash Phantom Stock Compensation 15.3 15.3 15.3 15.3 15.3 15.3 15.3 15.3 15.3 Base (53.5) (54.5) (56.6) (55.9) (54.6) (52.3) (49.2) (45.5) (41.1) (3.2%) From Acquisitions (1.1) (4.3) (9.1) (14.4) (19.6) (24.9) (30.1) (35.4) (40.6) 57.9% Interest Expense (54.5) (58.8) (65.7) (70.2) (74.2) (77.2) (79.3) (80.9) (81.7) 5.2% Taxes - - - - - - - - - Change in Working Capital - - - - - - - - - Growth Capex - - - - - - - - - Maintenance Capex (4.3) (6.9) (5.9) (6.5) (7.2) (7.8) (8.4) (9.0) (9.7) 10.5% Other 1.8 - - - - - - - - Distributable Cash Flow $ 157.6 $ 172.2 $ 176.2 $ 193.9 $ 211.3 $ 225.5 $ 238.2 $ 254.3 $ 267.0 6.8% Distribution - G.P. Interest 40.7 44.0 46.5 51.0 56.3 60.4 64.7 69.4 72.9 Less Standalone G&A (2.0) (2.0) (2.0) (2.0) (2.0) (2.0) (2.0) (2.0) (2.0) Unlevered Free Cash Flow $ 38.7 $ 42.0 $ 44.5 $ 49.0 $ 54.3 $ 58.4 $ 62.7 $ 67.4 $ 70.9 PV of Cash Flows PV of Terminal Value Enterprise Value Based Discount per L.P. Unit Based on DCF Multiples of: on DCF Multiples of: Rate ('08 -'16) 20.0x 25.0x 30.0x 20.0x 25.0x 30.0x 15.0% $258 $403 $504 $604 $661 $762 $862 16.0% $249 373 466 $559 622 715 808 17.0% $241 345 431 $518 586 672 758 $586 -- $862

Summary of G.P. Trading Comparables ___________________________ Source: Lehman Brothers Investment Banking. 1. Market Value of EPE's Other Businesses includes i) 4.4mm TPP common units and ii) 39.0mm ETE common units (both valued as of market close on 08/23/2007) Implied value of EPE’s General Partner Interest reflects value of i) EPD’s General Partner, ii) TPP’s General Partner and iii) 35% of ETE’s General Partner. Hold Co. Value of EPE reflects value of all its cash generating interests. Valuation Sensitivity Supplement G.P. HoldCo Peer Group 32 ($ in millions, except per unit) Currently Trading Alliance Atlas Pipeline Buckeye GP Crosstex Energy Transfer Enterprise GP Hiland Inergy Magellan NuStar GP Penn VA Group Holdings GP Holdings Holdings Energy, Inc. Equity Holdings (1) Holdings GP Holdings Midstream Holdings Holdings GP Holdings Median Avg. Price Per Share (as of 8/31/07) $25.20 $40.69 $31.40 $32.84 $36.75 $38.31 $30.23 $44.98 $28.31 $32.70 $31.42 Equity Value (as of 8/31/07) $1,508.5 $1,115.5 $888.6 $1,510.1 $8,188.9 $5,332.4 $653.0 $899.9 $1,773.5 $1,389.9 $1,227.7 Unconsolidated Net Debt (0.0) 23.1 22.0 (7.9) 1,562.7 1,073.3 0.3 31.4 (0.1) (2.7) (9.7) Enterprise Value $1,508.5 $1,138.6 $910.7 $1,502.2 $9,751.6 $6,405.8 $653.3 $931.3 $1,773.4 $1,387.1 $1,218.0 Common Units Held at Hold Co. 15.5 5.5 0.1 5.3 62.5 13.5 1.3 4.7 - 10.2 19.8 Current Market Price of MLP Units $33.51 $46.40 $49.05 $35.38 $52.04 $29.51 $50.01 $32.57 $43.00 $62.23 $27.84 Market Value of Common Units Held $520.9 $254.1 $3.9 $188.6 $3,252.5 $397.0 $65.1 $153.3 $0.0 $636.4 $551.4 Subordinated Units Held at Hold Co. - - - 11.1 - - 4.1 - - - - Discount Assumed to Market Price 5.0% 5.0% 5.0% 16.6% 5.0% 5.0% 5.0% 5.0% 5.0% 5.0% 5.0% Market Value of Subordinated Units Held $0.0 $0.0 $0.0 $327.1 $0.0 $0.0 $193.8 $0.0 $0.0 $0.0 $0.0 Other EBITDA - - - - - - - - - - - Multiple 5.0x 5.0x 5.0x 5.0x 5.0x 5.0x 5.0x 5.0x 5.0x 5.0x 5.0x Market Value of Other Businesses $0.0 $0.0 $0.0 $0.0 $0.0 $1,609.0 $0.0 $0.0 $0.0 $0.0 $0.0 Total Market Value of L.P. Equity Held $520.9 $254.1 $3.9 $515.8 $3,252.5 $397.0 $258.9 $153.3 $0.0 $636.4 $551.4 Total Market Value of Other Businesses 0.0 0.0 0.0 0.0 0.0 1,609.0 0.0 0.0 0.0 0.0 0.0 Enterprise Value of Hold Co. 1,508.5 1,138.6 910.7 1,502.2 9,751.6 6,405.8 653.3 931.3 1,773.4 1,387.1 1,218.0 Implied Value of General Partner Interest $987.6 $884.5 $906.7 $986.5 $6,499.1 $4,399.7 $394.3 $778.0 $1,773.4 $750.8 $666.6 Implied G.P. Value as a Multiple of: Distributable Cash Flow (After G&A) - 2007E 16.8x 23.5x 23.4x 36.4x 24.7x 21.0x 59.1x 22.6x 19.3x 30.2x 32.1x 23.5x 28.1x 2008E 18.6x 13.5x 22.6x 20.2x 17.4x 19.8x 33.4x 18.1x 17.2x 22.7x 25.3x 19.8x 20.8x Distributions (After G&A) - Latest Annualized 32.5x 28.5x 26.0x 38.5x 27.9x 25.7x 105.2x 24.6x 25.6x 40.5x 55.4x 28.5x 39.1x 2007E 30.6x 26.2x 25.2x 36.9x 26.4x 25.5x 81.0x 23.0x 24.4x 34.5x 55.4x 26.4x 35.4x 2008E 22.8x 19.0x 22.8x 21.3x 18.7x 22.3x 49.0x 19.9x 20.8x 31.9x 38.7x 22.3x 26.1x Hold Co. Value as a Multiple of: Distributable Cash Flow (After G&A) - 2007E 14.3x 18.8x 23.4x 29.8x 20.4x 19.1x 27.1x 20.4x 19.3x 20.4x 21.1x 20.4x 21.3x 2008E 15.5x 12.5x 22.5x 20.1x 15.5x 17.1x 20.8x 16.9x 17.2x 17.0x 18.5x 17.1x 17.6x Distributions (After G&A) - Latest Annualized 23.1x 22.7x 25.9x 31.0x 22.5x 24.0x 33.5x 21.8x 25.6x 24.2x 26.9x 24.2x 25.6x 2007E 22.2x 21.4x 25.2x 30.1x 21.5x 22.3x 30.7x 20.6x 24.4x 22.1x 26.9x 22.3x 24.3x 2008E 18.0x 16.9x 22.8x 21.0x 16.5x 19.5x 25.4x 18.3x 20.8x 21.1x 23.1x 20.8x 20.3x Latest Annualized HoldCo Dividend / Distribution $1.06 $1.04 $1.00 $0.92 $1.49 $1.52 $0.88 $2.04 $1.10 $1.36 $1.12 Implied Pre-Tax Yield 4.21% 2.56% 3.18% 2.80% 4.05% 3.97% 2.91% 4.54% 3.90% 4.16% 3.56% 3.90% 3.62% Expected MLP Distribution CAGR 12.0% 5.0% 6.0% 8.0% 18.0% 8.0% 10.0% 6.0% 9.0% 7.0% 8.0% 8.0% 8.8% Resulting Holdco Distribution CAGR 18.5% 14.2% 10.0% 12.9% 23.4% 16.9% 18.3% 14.3% 17.6% 10.6% 16.0% 16.0% 15.7% Multiplier 1.5x 2.8x 1.7x 1.6x 1.3x 2.1x 1.8x 2.4x 2.0x 1.5x 2.0x 1.8x 1.9x

Summary of G.P. Transactions ___________________________ Based on public disclosure or Lehman Brothers estimates. Assumes 5% discount to last trade on June 15, 2007; includes 16.7 million subordinated units owned by HM Capital and 1.1 million subordinated units owned by Management. Net of 4.4 million L.P. units valued at unit price of $45.38 as of May 7, 2007. Net of 13.5 million L.P. units valued at unit price of $26.60 as of January 13, 2005. Net of 5.1 million L.P. units valued at the L.P. unit offering price of $61.50 per unit, a premium of 21% over the closing price of $50.76 per unit as of October 29, 2004. Assumes that 500,000 L.P. units purchased in conjunction with general partner interest were valued at par to closing price of $41.05 per unit as of September 16, 2004. While 42.25% of the G.P. was sold, only 10.0% of the IDRs were sold. Total transaction value consists of $510 million cash at closing, assumption of a $19 million environmental liability, an additional $2 million from first post-closing unitholder distribution and $50 million of assumed G&A cap. Implied G.P. value calculated using discount of 5% on 1.1 million common units, 15% discount on 5.7 million subordinated units and 20% discount on 7.8 million Class A units Valuation Sensitivity Supplement 33 ($ millions) Implied Distributable Cash Flow Distributed Cash Flow Total GP Interest GP Value Percent of Implied Annualized Implied Announce Transaction as % GP Interest LTM DCF GP DCF Implied Distribution Distribution Implied Date Acquirer / Target Value (1) of Total Sold to GP Multiple Yield to GP Multiple Yield 6/19/07 GE Energy Financial Services $603.0 $176.0 (2) 29% 100% $1.2 145.7x 0.7% $1.5 115.8x 0.9% Regency GP LP (the G.P.) 5/7/07 Enterprise GP Holdings L.P. $1,100.0 $900.3 (3) 82% 100% $70.3 12.8x 7.8% $48.3 18.6x 5.4% Texas Eastern Products Pipeline Company, LLC 4/4/07 ArcLight Capital Parnters, Kelso & Company and Lehman Brothers n.a. n.a. n.a. 63% $27.5 n.m. n.m. $31.0 n.m. n.m. Buckeye GP Holdings (the G.P.) 10/19/06 Suburban Propane Partners, L.P. $75.0 $75.0 100% 100% $5.1 14.7x 6.8% $3.0 25.0x 4.0% Suburban Energy Services Group LLC (the G.P.) 6/12/06 Plains All American Pipeline, L.P. $2,324.9 $328.5 14% 100% $2.6 n.m. n.m. $3.2 n.m. n.m. Pacific Energy Partners, L.P. 2/15/06 ONEOK, Inc. $40.0 $40.0 100% 18% $18.5 12.4x 8.1% $11.2 20.5x 4.9% TransCanada's GP Interest in Norther Border Partners, L.P. 2/24/05 EPCO, Inc. $1,100.0 $1,100.0 100% 100% $68.2 16.1x 6.2% $67.7 16.3x 6.2% TEPPCO 1/14/05 EPCO, Inc. $425.0 $67.1 (4) 16% 10% $87.9 7.7x 13.0% $67.8 10.0x 10.0% Enterprise Products GP LLC 11/1/04 Valero L.P. $545.2 $231.7 (5) 43% 100% $14.8 15.6x 6.4% $11.0 21.2x 4.7% Kaneb Pipe Line Partners, L.P. 10/29/04 LB Pacific, L.P. (not disclosed) n.a. n.a. n.a. 100% $1.7 n.a. n.a. $1.2 n.a. n.a. Pacific Energy Partners, L.P. 9/17/04 ONEOK, Inc. $175.0 $154.5 (6) 88% 83% $17.8 10.5x 9.5% $11.2 16.8x 6.0% Northern Plains (G.P. of Northern Border Partners, L.P.) 3/5/04 Carlyle/Riverstone $235.0 $235.0 100% 100% $13.4 17.5x 5.7% $14.2 16.6x 6.0% Glenmoor, Ltd. (parent of G.P. of Buckeye Partners, L.P.) 12/22/03 First Reserve / Corbin Robertson / Mgmt. $115.0 $4.0 3% 42% (7) $2.1 7.3x 13.6% $1.0 9.4x 10.6% Arch Coal, Inc.'s G.P. interest in Natural Resource Partners, L.P. 12/15/03 Enterprise Products Partners L.P. $4,633.4 $425.0 9% 50% $82.8 10.3x 9.7% $84.5 10.1x 9.9% GulfTerra Energy Partners, L.P. 11/20/03 Vulcan Capital $470.4 $78.0 17% 44% $11.2 15.9x 6.3% $10.7 16.5x 6.0% Plains Resources Inc. 11/6/03 Energy Transfer Company $130.0 $30.0 23% 100% $4.6 6.5x 15.5% $2.3 13.3x 7.5% U.S. Propane L.P. (G.P. of Heritage Propane Partners, L.P.) 10/3/03 Goldman Sachs n.a. $88.0 n.a. 10% $77.8 11.4x 8.8% $71.3 12.5x 8.0% GulfTerra Energy Partners, L.P. 4/21/03 Madison Dearborn / Riverstone $581.0 (8) $133.2 (9) 23% 100% $18.7 7.1x 14.1% $5.3 25.2x 4.0% Williams Energy Partners L.P. Mean of 2006-2007 transactions 46.4x 0.1x 45.0x 3.8% Median of 2006-2007 transactions 13.8x 0.1x 22.7x 4.4% Mean of 2004-2007 transactions 28.1x 7.1% 29.0x 5.3% Median of 2004-2007 transactions 14.7x 6.8% 18.6x 5.4% Mean of all transactions 20.8x 8.8% 23.2x 6.3% Median of all transactions 12.4x 8.1% 16.6x 6.0% Value Transaction

NGL Business Valuation (Pre-Tax) Valuation Analysis Detailed Projections Discounted Cash Flow Analysis Base Case (Management Commodity Case) ___________________________ We have assumed standalone cash SG&A expense of $4 million per management. 34 2008E 2009E 2010E 2011E 2012E 2013E 2014E 2015E 2016E CAGR EBITDA $22.1 $16.6 $20.0 $21.4 $20.0 $18.8 $17.6 $16.4 $15.2 (4.6%) SG&A (1) (4.0) (4.0) (4.0) (4.0) (4.0) (4.0) (4.0) (4.0) (4.0) Distributable Cash Flow $ 18.1 $ 12.6 $ 16.0 $ 17.4 $ 16.0 $ 14.8 $ 13.6 $ 12.4 $ 11.2 (5.9%) PV of Cash Flows PV of Terminal Value Based per L.P. Unit on Perpetuity Growth Rate of: ('08 -'16) (7.5%) (5.0%) (2.5%) $97 $33 $41 $52 94 29 35 44 91 25 30 37 Equity Value based on Discount Perpetuity Growth Rate of: Rate (7.5%) (5.0%) (2.5%) 8.0% $130 $138 $149 10.0% 123 129 137 12.0% 116 121 128 $116 -- $149

Valuation Sensitivity Supplement

MWE L.P. Unit Valuation Summary (Pre-Tax) Detailed Projections Valuation Analysis Supplement Discounted Cash Flow Analysis Strip Price Case 35 2008E 2009E 2010E 2011E 2012E 2013E 2014E 2015E 2016E CAGR EBITDA Base $ 194.0 $ 204.1 $ 196.1 $ 200.5 $ 203.9 $ 204.0 $ 201.7 $ 198.2 $ 194.7 0.0% EBITDA from Acquisitions 3.8 15.3 32.4 51.0 69.5 88.0 106.6 125.1 143.6 37.7% EBITDA 197.7 219.4 228.5 251.5 273.4 292.0 308.2 323.2 338.3 6.9% Plus Non-Cash Phantom Stock Compensation 15.3 15.3 15.3 15.3 15.3 15.3 15.3 15.3 15.3 Base (53.7) (54.8) (56.8) (56.0) (54.1) (51.1) (46.9) (42.0) (36.4) (4.8%) From Acquisitions (1.1) (4.3) (9.1) (14.4) (19.6) (24.9) (30.1) (35.4) (40.6) 57.9% Interest Expense (54.8) (59.1) (65.9) (70.3) (73.7) (75.9) (77.0) (77.4) (77.0) 4.3% Taxes - - - - - - - - - Change in Working Capital - - - - - - - - - Growth Capex - - - - - - - - - Maintenance Capex (4.3) (6.9) (5.9) (6.5) (7.2) (7.8) (8.4) (9.0) (9.7) 10.5% Other 1.8 - - - - - - - - Distributable Cash Flow $ 155.7 $ 168.7 $ 172.0 $ 190.0 $ 207.8 $ 223.6 $ 238.1 $ 252.1 $ 267.0 7.0% PV of Cash Flows PV of Terminal Value Based Equity Value per Unit Based Discount per L.P. Unit on Perpetuity Growth Rate of: on Perpetuty Growth Rates of: Rate ('08 -'16) 0.0% 0.5% 1.0% 0.0% 0.5% 1.0% 9.0% $17.90 $15.68 $16.69 $17.82 $33.58 $34.58 $35.71 11.0% 16.65 10.89 11.47 12.10 27.54 28.12 28.75 13.0% 15.54 7.85 8.20 8.59 23.39 23.74 24.13 $23.39 -- $35.71

MWE GP Valuation (Pre-Tax) Discounted Cash Flow Analysis Valuation Analysis Supplement Detailed Projections Strip Price Case 36 2008E 2009E 2010E 2011E 2012E 2013E 2014E 2015E 2016E CAGR EBITDA Base $ 194.0 $ 204.1 $ 196.1 $ 200.5 $ 203.9 $ 204.0 $ 201.7 $ 198.2 $ 194.7 0.0% EBITDA from Acquisitions 3.8 15.3 32.4 51.0 69.5 88.0 106.6 125.1 143.6 37.7% EBITDA 197.7 219.4 228.5 251.5 273.4 292.0 308.2 323.2 338.3 6.9% Plus Non-Cash Phantom Stock Compensation 15.3 15.3 15.3 15.3 15.3 15.3 15.3 15.3 15.3 Base (53.7) (54.8) (56.8) (56.0) (54.1) (51.1) (46.9) (42.0) (36.4) (4.8%) From Acquisitions (1.1) (4.3) (9.1) (14.4) (19.6) (24.9) (30.1) (35.4) (40.6) 57.9% Interest Expense (54.8) (59.1) (65.9) (70.3) (73.7) (75.9) (77.0) (77.4) (77.0) 4.3% Taxes - - - - - - - - - Change in Working Capital - - - - - - - - - Growth Capex - - - - - - - - - Maintenance Capex (4.3) (6.9) (5.9) (6.5) (7.2) (7.8) (8.4) (9.0) (9.7) 10.5% Other 1.8 - - - - - - - - Distributable Cash Flow $ 155.7 $ 168.7 $ 172.0 $ 190.0 $ 207.8 $ 223.6 $ 238.1 $ 252.1 $ 267.0 7.0% Distribution - G.P. Interest 39.6 42.4 44.8 49.5 54.9 59.8 64.2 68.7 72.7 Less Standalone G&A (2.0) (2.0) (2.0) (2.0) (2.0) (2.0) (2.0) (2.0) (2.0) Unlevered Free Cash Flow $ 37.6 $ 40.4 $ 42.8 $ 47.5 $ 52.9 $ 57.8 $ 62.2 $ 66.7 $ 70.7 PV of Cash Flows PV of Terminal Value Enterprise Value Based Discount per L.P. Unit Based on DCF Multiples of: on DCF Multiples of: Rate ('08 -'16) 20.0x 25.0x 30.0x 20.0x 25.0x 30.0x 15.0% $252 $402 $502 $603 $654 $755 $855 16.0% $243 372 465 $558 615 708 801 17.0% $235 344 430 $516 579 665 751 $579 -- $855

NGL Business Valuation (Pre-Tax) Valuation Analysis Detailed Projections Discounted Cash Flow Analysis ___________________________ We have assumed standalone cash SG&A expense of $4 million per management. Strip Price Case 37 2008E 2009E 2010E 2011E 2012E 2013E 2014E 2015E 2016E CAGR EBITDA $20.7 $15.4 $17.2 $18.0 $18.3 $18.1 $17.8 $17.5 $17.3 (2.2%) SG&A (1) (4.0) (4.0) (4.0) (4.0) (4.0) (4.0) (4.0) (4.0) (4.0) Distributable Cash Flow $ 16.7 $ 11.4 $ 13.2 $ 14.0 $ 14.3 $ 14.1 $ 13.8 $ 13.5 $ 13.3 (2.8%) PV of Cash Flows PV of Terminal Value Based per L.P. Unit on Perpetuity Growth Rate of: ('08 -'16) (7.5%) (5.0%) (2.5%) $90 $40 $48 $62 87 34 41 52 84 30 36 44 Equity Value based on Discount Perpetuity Growth Rate of: Rate (7.5%) (5.0%) (2.5%) 8.0% $130 $138 $152 10.0% 121 128 139 12.0% 114 119 128 $114 -- $152

MWP Tax Calculations Discounted Cash Flow Analysis Valuation Analysis Projections of the NGL Business ___________________________ We have assumes standalone cash SG&A expense of $4 million per management. Strip Price Case 38 NGL Business Tax Calculation 2008E 2009E 2010E 2011E 2012E 2013E 2014E 2015E 2016E CAGR Revenue $200.8 $193.6 $193.7 $194.5 $194.3 $194.3 $194.3 $194.3 $194.3 (0.4%) Operating Expenses (180.1) (178.2) (176.5) (176.5) (176.0) (176.3) (176.5) (176.8) (177.1) SG&A (20.3) (20.7) (21.1) (21.5) (22.0) (22.4) (22.9) (23.3) (23.8) MLP Equity Income 29.1 31.6 32.0 34.9 37.8 40.4 42.8 45.2 47.7 EBITDA $29.4 $26.3 $28.1 $31.4 $34.2 $36.0 $37.8 $39.4 $41.1 4.3% Taxable Income Interest Income 2.9 3.6 4.2 4.8 5.5 6.2 6.9 7.6 8.3 DDD&A and Other (0.8) (0.5) (0.5) (0.5) (0.5) (0.5) (0.5) (0.5) (0.5) Less MLP Equity Income (29.1) (31.6) (32.0) (34.9) (37.8) (40.4) (42.8) (45.2) (47.7) Plus Allocated MLP Taxable Income 45.3 46.9 48.6 50.6 52.6 54.6 56.6 58.6 60.5 Plus Non-Deductible SG&A 8.8 9.0 9.2 9.3 9.5 9.7 9.9 10.1 10.3 Pre-Tax Income $56.6 $53.6 $57.5 $60.7 $63.5 $65.6 $67.8 $69.9 $72.1 3.1% Tax Rate 37.7% 37.7% 37.7% 37.7% 37.7% 37.7% 37.7% 37.7% 37.7% NGL Business Taxes Paid ($21.3) ($20.2) ($21.7) ($22.9) ($23.9) ($24.8) ($25.6) ($26.4) ($27.2) 3.1% MWP New Debt Tax Shield Calculation 2008E 2009E 2010E 2011E 2012E 2013E 2014E 2015E 2016E CAGR Interest on Acquisition Debt ($20.7) ($20.7) ($20.7) ($20.7) ($20.7) ($20.7) ($20.7) ($20.7) ($20.7) NM Tax Rate 37.7% 37.7% 37.7% 37.7% 37.7% 37.7% 37.7% 37.7% 37.7% MWP New Debt Tax Shield $7.8 $7.8 $7.8 $7.8 $7.8 $7.8 $7.8 $7.8 $7.8 NM PV of Cash Flows PV of Terminal Value Based Discount per L.P. Unit on Perpetuity Growth Rate of: Equity Value Tax Shield Rate ('08 -'16) (1.0%) 0.0% 1.0% (1.0%) 0.0% 1.0% Equity Value 10.0% $ (140) $ (104) $ (115) $ (129) $ (244) $ (256) $ (270) $ 78 12.0% (130) (75) (82) (90) (205) (212) (221) $ 65 14.0% (122) (55) (60) (65) (177) (181) (187) $ 56 $ (209) -- $ (226) $ 66 Actual Tax Impact $ (142) -- $ (159)

MWE L.P. Unit Valuation Summary (Pre-Tax) Detailed Projections Valuation Analysis Supplement Discounted Cash Flow Analysis $50 / $7 Case 39 2008E 2009E 2010E 2011E 2012E 2013E 2014E 2015E 2016E CAGR EBITDA Base $ 199.2 $ 190.4 $ 176.1 $ 174.9 $ 178.5 $ 178.7 $ 176.4 $ 173.1 $ 169.8 (2.0%) EBITDA from Acquisitions 3.8 15.3 32.4 51.0 69.5 88.0 106.6 125.1 143.6 37.7% EBITDA 203.0 205.7 208.5 225.8 248.0 266.7 283.0 298.2 313.4 5.6% Plus Non-Cash Phantom Stock Compensation 15.3 15.3 15.3 15.3 15.3 15.3 15.3 15.3 15.3 Base (54.2) (55.5) (58.5) (59.8) (60.6) (60.4) (59.4) (57.9) (56.0) 0.4% From Acquisitions (1.1) (4.3) (9.1) (14.4) (19.6) (24.9) (30.1) (35.4) (40.6) 57.9% Interest Expense (55.2) (59.8) (67.6) (74.1) (80.2) (85.3) (89.5) (93.3) (96.6) 7.2% Taxes - - - - - - - - - Change in Working Capital - - - - - - - - - Growth Capex - - - - - - - - - Maintenance Capex (4.3) (6.9) (5.9) (6.5) (7.2) (7.8) (8.4) (9.0) (9.7) 10.5% Other 1.8 - - - - - - - - Distributable Cash Flow $ 160.5 $ 154.3 $ 150.4 $ 160.4 $ 176.0 $ 188.9 $ 200.4 $ 211.2 $ 222.4 4.2% PV of Cash Flows PV of Terminal Value Based Equity Value per Unit Based Discount per L.P. Unit on Perpetuity Growth Rate of: on Perpetuty Growth Rates of: Rate ('08 -'16) 0.0% 0.5% 1.0% 0.0% 0.5% 1.0% 9.0% $16.25 $13.50 $14.36 $15.33 $29.75 $30.61 $31.59 11.0% 15.15 9.37 9.87 10.42 24.53 25.02 25.57 13.0% 14.18 6.75 7.06 7.39 20.93 21.24 21.57 $20.93 -- $31.59

MWE GP Valuation (Pre-Tax) Discounted Cash Flow Analysis Valuation Analysis Supplement Detailed Projections $50 / $7 Case 40 2008E 2009E 2010E 2011E 2012E 2013E 2014E 2015E 2016E CAGR EBITDA Base $ 199.2 $ 190.4 $ 176.1 $ 174.9 $ 178.5 $ 178.7 $ 176.4 $ 173.1 $ 169.8 (2.0%) EBITDA from Acquisitions 3.8 15.3 32.4 51.0 69.5 88.0 106.6 125.1 143.6 37.7% EBITDA 203.0 205.7 208.5 225.8 248.0 266.7 283.0 298.2 313.4 5.6% Plus Non-Cash Phantom Stock Compensation 15.3 15.3 15.3 15.3 15.3 15.3 15.3 15.3 15.3 Base (54.2) (55.5) (58.5) (59.8) (60.6) (60.4) (59.4) (57.9) (56.0) 0.4% From Acquisitions (1.1) (4.3) (9.1) (14.4) (19.6) (24.9) (30.1) (35.4) (40.6) 57.9% Interest Expense (55.2) (59.8) (67.6) (74.1) (80.2) (85.3) (89.5) (93.3) (96.6) 7.2% Taxes - - - - - - - - - Change in Working Capital - - - - - - - - - Growth Capex - - - - - - - - - Maintenance Capex (4.3) (6.9) (5.9) (6.5) (7.2) (7.8) (8.4) (9.0) (9.7) 10.5% Other 1.8 - - - - - - - - Distributable Cash Flow $ 160.5 $ 154.3 $ 150.4 $ 160.4 $ 176.0 $ 188.9 $ 200.4 $ 211.2 $ 222.4 4.2% Distribution - G.P. Interest 40.1 41.7 44.0 46.6 49.1 51.7 54.3 56.8 59.4 Less Standalone G&A (2.0) (2.0) (2.0) (2.0) (2.0) (2.0) (2.0) (2.0) (2.0) Unlevered Free Cash Flow $ 38.1 $ 39.7 $ 42.0 $ 44.6 $ 47.1 $ 49.7 $ 52.3 $ 54.8 $ 57.4 PV of Cash Flows PV of Terminal Value Enterprise Value Based Discount per L.P. Unit Based on DCF Multiples of: on DCF Multiples of: Rate ('08 -'16) 20.0x 25.0x 30.0x 20.0x 25.0x 30.0x 15.0% $231 $326 $408 $489 $557 $639 $720 16.0% $223 302 377 $453 525 600 676 17.0% $216 279 349 $419 495 565 635 $495 -- $720

NGL Business Valuation (Pre-Tax) Valuation Analysis Detailed Projections Discounted Cash Flow Analysis ___________________________ We have assumed standalone cash SG&A expense of $4 million per management. $50 / $7 Case 41 2008E 2009E 2010E 2011E 2012E 2013E 2014E 2015E 2016E CAGR EBITDA $12.8 $9.0 ($0.5) ($5.2) ($5.5) ($5.7) ($6.0) ($6.3) ($6.6) NA SG&A (1) (4.0) (4.0) (4.0) (4.0) (4.0) (4.0) (4.0) (4.0) (4.0) Distributable Cash Flow $ 8.8 $ 5.0 $ (4.5) $ (9.2) $ (9.5) $ (9.7) $ (10.0) $ (10.3) $ (10.6) NA PV of Cash Flows PV of Terminal Value Based per L.P. Unit on Perpetuity Growth Rate of: ('08 -'16) (7.5%) (5.0%) (2.5%) $(28) $(32) $(39) $(49) (26) (27) (33) (41) (25) (24) (28) (35) Equity Value based on Discount Perpetuity Growth Rate of: Rate (7.5%) (5.0%) (2.5%) 8.0% $(60) $(67) $(77) 10.0% (54) (59) (68) 12.0% (48) (53) (59) $(77) -- $(48)

MWP Tax Calculations Discounted Cash Flow Analysis Valuation Analysis Projections of the NGL Business ___________________________ We have assumes standalone cash SG&A expense of $4 million per management. $50 / $7 Case 42 NGL Business Tax Calculation 2008E 2009E 2010E 2011E 2012E 2013E 2014E 2015E 2016E CAGR Revenue $177.0 $169.6 $155.2 $150.0 $150.0 $150.0 $150.0 $150.0 $150.0 (2.1%) Operating Expenses (164.2) (160.6) (155.7) (155.2) (155.4) (155.7) (156.0) (156.2) (156.5) SG&A (20.3) (20.7) (21.1) (21.5) (22.0) (22.4) (22.9) (23.3) (23.8) MLP Equity Income 29.8 29.5 29.1 31.1 33.8 36.2 38.4 40.6 42.8 EBITDA $22.2 $17.8 $7.4 $4.3 $6.3 $8.0 $9.6 $11.0 $12.5 (7.0%) Taxable Income Interest Income 2.4 2.9 3.3 3.4 3.4 3.5 3.5 3.5 3.6 DDD&A and Other (0.8) (0.5) (0.5) (0.5) (0.5) (0.5) (0.5) (0.5) (0.5) Less MLP Equity Income (29.8) (29.5) (29.1) (31.1) (33.8) (36.2) (38.4) (40.6) (42.8) Plus Allocated MLP Taxable Income 45.3 46.9 48.6 50.6 52.6 54.6 56.6 58.6 60.5 Plus Non-Deductible SG&A 8.8 9.0 9.2 9.3 9.5 9.7 9.9 10.1 10.3 Pre-Tax Income $48.2 $46.5 $38.9 $36.0 $37.6 $39.1 $40.6 $42.1 $43.5 (1.3%) Tax Rate 37.7% 37.7% 37.7% 37.7% 37.7% 37.7% 37.7% 37.7% 37.7% NGL Business Taxes Paid ($18.2) ($17.5) ($14.7) ($13.6) ($14.2) ($14.7) ($15.3) ($15.9) ($16.4) (1.3%) MWP New Debt Tax Shield Calculation 2008E 2009E 2010E 2011E 2012E 2013E 2014E 2015E 2016E CAGR Interest on Acquisition Debt ($20.7) ($20.7) ($20.7) ($20.7) ($20.7) ($20.7) ($20.7) ($20.7) ($20.7) NM Tax Rate 37.7% 37.7% 37.7% 37.7% 37.7% 37.7% 37.7% 37.7% 37.7% MWP New Debt Tax Shield $7.8 $7.8 $7.8 $7.8 $7.8 $7.8 $7.8 $7.8 $7.8 NM PV of Cash Flows PV of Terminal Value Based Discount per L.P. Unit on Perpetuity Growth Rate of: Equity Value Tax Shield Rate ('08 -'16) (1.0%) 0.0% 1.0% (1.0%) 0.0% 1.0% Equity Value 10.0% $ (95) $ (63) $ (70) $ (78) $ (158) $ (165) $ (173) $ 78 12.0% (89) (45) (49) (54) (134) (138) (143) $ 65 14.0% (84) (33) (36) (39) (117) (120) (123) $ 56 $ (136) -- $ (146) $ 66 Actual Tax Impact $ (70) -- $ (80)

Other Considerations

Increasingly Competitive M&A Market is Driving MLPs to Evaluate Their Cost of Capital Other Considerations Enterprise Products Partners L.P. In December 2002, EPD permanently capped its splits at 25% At the time, EPD was in the 25% split level Valero L.P. In March 2004, VLI permanently capped its splits at 25% At the time, VLI was in the 10% split level TEPPCO Partners, L.P. In December 2006, TPP permanently capped its splits at 25% (received unitholder approval on 12/8/06) At the time, TPP was currently in the 50% split level General partner received L.P. units in exchange for split reduction on a cash flow neutral basis Suburban Propane Partners, L.P. The MLP agreed to recapitalize the General Partner’s economic interest and IDRs The G.P. of SPH was capped at the 15% split level prior to the recapitalization Consideration given was common units Permanent Magellan Midstream Partners, L.P. In connection with the acquisition of assets from Shell in June 2004, MMP’s general partner agreed to a temporary reduction in its portion of cash distributions $1.25 million in 2004; $5 million in 2005; $3 million in 2006 Plains All American Pipeline, L.P. As part of the agreement to buy Pacific Energy Partners, L.P., Plains’ general partner agreed to reduce its incentive distribution right payments by an aggregate of $65 million through 2011 Transaction-Driven, Temporary IDR Modifications MLPs have taken two primary approaches: (i) permanent reduction, cap or elimination of the splits and (ii) transaction-driven temporary modifications There has also been one “option” to reset the IDR levels, as discussed below The temporary modifications have both been undertaken to better match cash flows from growth projects Enterprise Products Partners, L.P. As part of the Gulfterra acquisition, EPCO contributed its 50% ownership interest to EPD for no consideration DCP Midstream Partners, L.P. General partner has the option to reset the splits to 98%/2% in exchange for L.P. equity on a cash flow neutral basis Other IDR Modifications Other Considerations 43

One commonly used method of calculating the cost of an MLP’s equity capital is dividing the MLP’s L.P. 2007E distributable cash flow yield by (1 - current IDR split %) This calculation attempts to capture the “true” L.P. cost of equity, fully burdened by the marginal G.P. take Currently, among selected small-capitalization midstream MLPs, only Atlas and Hiland have a higher cost of capital than MWE Among the group shown below, notably, Copano does not have any IDRs Some of the other MLPs with a low cost of equity capital are newly-formed and lower in their respective IDR structures The 8.2% “MWE Without IDRs” equity cost of capital assumes the IDRs are eliminated and the 2007E DCF yield is held constant While we have held the DCF yield constant at 8.2% for illustrative purposes, we believe MWE could also potentially benefit from a tightening of yield – although given the announcement, the market yield already reflects some tightening due to transaction anticipation This analysis is designed to be illustrative, as we believe there are numerous factors that are reflected in an MLP’s yield such as commodity price volatility, drop-down stories, organic growth, perceived future success in M&A market, management track record, etc. Nonetheless, taken in isolation, an MLP’s yield should improve with the removal of its IDRs as ability to grow LP DCF is enhanced Other Considerations Removing the IDRs Should Improve MWE’s Cost of Capital Other Considerations Selected Illustrative MLP Equity Costs of Capital (1) ___________________________ Equity cost of capital calculated as 2007E L.P. distributable cash flow yield divided by (1 - current IDR split %). 2007E estimates per Wall Street Research. 44 4.40% 5.40% 6.60% 7.00% 7.20% 8.20% 10.20% 10.40% 11.20% 13.20% 16.30% 0% 2% 4% 6% 8% 10% 12% 14% 16% 18% SGLP RGNC CPNO DEP NGLS MWE DPM MMLP WPZ HLND MWE Cost of Capital DCF Yield Current Split Level 4.3% 5.3% 6.6% 6.9% 7.1% 8.2% 5.1% 7.8% 5.6% 6.6% 8.2% 2.0% 2.0% 0.0% 2.0% 2.0% 0.0% 50.0% 25.0% 50.0% 50.0% 50.0%

Other Considerations Ownership structure as of July 31, 2007 Other Considerations MWP MWE ___________________________ Source: Thomson Financial. 45 Pos. Name Shares as % 1 JOHN M. FOX 5,377,446 44.6% 2 KAYNE ANDERSON CAP ADVISORS 647,413 5.4% 3 BEAR STEARNS ASSET MGMT 560,435 4.6% 4 SWANK GROUP 542,467 4.5% 5 HENNESSY ADVISORS 413,700 3.4% 6 FRIEDMAN BILLINGS RAMSEY 397,890 3.3% 7 RENAISSANCE TECHNOLOGIES 378,340 3.1% 8 AKRE CAPITAL MANAGEMENT 361,998 3.0% 9 BARCLAYS GBL INVESTORS 306,281 2.5% 10 DIMENSIONAL FD ADVISORS 291,740 2.4% 11 STATE STR GLOBAL 196,810 1.6% 12 GPS PARTNERS 195,733 1.6% 13 AMERICAN CENT INVESTMENT 179,890 1.5% 14 VANGUARD GROUP 177,844 1.5% 15 WELLS CAPITAL MANAGEMENT 114,889 1.0% 16 DALTON GREINER HARTMAN MAHER 105,448 0.9% 17 AMERICAN CENT INVT MGMT 96,199 0.8% 18 COLLEGE RETIREMENT EQUITIES 78,348 0.7% 19 CNA INSURANCE COMPANIES 71,849 0.6% 20 ZIMMER LUCAS PARTNERS 50,015 0.4% Top 20 10,544,735 87.5% Pos. Name Shares as % 1 MARKWEST HYDROCARBON, INC. 4,938,992 13.3% 2 TORTOISE CAPITAL ADVISORS 3,495,330 9.4% 3 KAYNE ANDERSON CAP ADVISORS 3,284,500 8.8% 4 SWANK GROUP 2,457,163 6.6% 5 NEUBERGER BERMAN 2,009,287 5.4% 6 FIDUCIARY ASSET MGMT 689,150 1.9% 7 GPS PARTNERS 663,544 1.8% 8 LEHMAN BROTHERS 631,665 1.7% 9 MORGAN STANLEY INV MGMT 533,645 1.4% 10 ZIMMER LUCAS PARTNERS 296,879 0.8% 11 DEUTSCHE ASSET MGMT AMERICAS 259,410 0.7% 12 EAGLE GLOBAL ADVISORS 240,420 0.6% 13 CITI INVESTMENT RESEARCH 226,025 0.6% 14 JOHN M. FOX 180,924 0.5% 15 CNA INSURANCE COMPANIES 176,000 0.5% 16 RR ADVISORS 147,520 0.4% 17 GOLDMAN SACHS & COMPANY 130,603 0.4% 18 RENAISSANCE TECHNOLOGIES 84,300 0.2% 19 WOOD & COMPANY 79,128 0.2% 20 SEMPLE (FRANK M) 67,484 0.2% Top 20 20,591,969 55.5%

EX-99.(C)(II)

Exhibit (c)(ii)

DRAFT Deal Committee of the Board of Directors of MarkWest Hydrocarbon, Inc. Materials Prepared for: September 5, 2007 CONFIDENTIAL

Table of Contents Materials Prepared for the Deal Committee of the Board of Directors of MarkWest Hydrocarbon, Inc. 1. Situation Analysis 1 2. Overview of Transaction 10 3. Summary Valuation 15 A. Discounted Cash Flow Analysis 29 B. Comparable Company Trading Analysis 34 C. Comparable Acquisition Analysis 39 D. Cost of Equity 44 4. Pro Forma Analysis 46

Situation Analysis

1 Situation Analysis Overview Merrill Lynch & Co. (“Merrill Lynch”) has been retained by the Deal Committee (the “Deal Committee”) of the Board of Directors of MarkWest Hydrocarbon, Inc. (“MWP”) to act as financial advisor and render a fairness opinion (the “Opinion”) in connection with the acquisition of MWP by MarkWest Energy Partners, L.P. (“MWE”) pursuant to the Agreement and Plan of Redemption and Merger (the “Agreement”). The acquisition has 2-steps: (i) a first step redemption by MWP for cash (the “Redemption”) of those shares of MWP common stock electing to receive the cash consideration followed immediately by (ii) the merger (the “Merger” and, together with the Redemption, the “Transaction”) of a wholly owned subsidiary of MWE with and into MWP with MWP surviving such transaction as a wholly owned subsidiary of MWE. Each outstanding share of MWP’s common stock (other than certain shares as set forth in the Agreement) will be converted into the right to receive, at the election of the holder thereof: (i) stated consideration fixed at $20.00 in cash from MWP plus 1.285 common units of MWE; (ii) common units of MWE; or (iii) cash from MWP, both (ii) and (iii) are subject to proration and other adjustments set forth in the Agreement, and in either case have a value equal to the sum of $20.00 plus the value of 1.285 MWE units (the “Merger/Redemption Consideration”). Based on MWE’s closing unit price of $31.88 on August 31, 2007, the Merger/Redemption Consideration is equal to $60.97 per MWP share, or a 21.2% premium to MWP’s price per share as of August 31, 2007 of $50.29 Merrill Lynch has been asked whether the Merger/Redemption Consideration if fair from a financial point to the holders of MWP shares other than the Fox Family Holders and their respective affiliates (as such terms are defined in the Agreement) and the respective officers and directors of MWP and the MWE GP general partner of MWE. The materials herein contain: An update of the events and the market dynamics affecting the Transaction to date; An overview of the Transaction; A summary valuation of MWP; and A review of the pro forma impact of the Transaction on MWE.

2 Situation Analysis Current Ownership Structure Public 6,374,142 MWP Shares MarkWest Hydrocarbon, Inc. 4,938,992 MWE Common Units Officers / Directors 523,490 MWE Common Units 5,627,067 MWP Shares MarkWest Energy GP, L.L.C. Public 31,037,427 MWE Common Units MarkWest Energy Partners, L.P. 36,499,909 Total Common Units 53.1% 46.9% 89.7% 10.3% 85.0% L.P. Interest 13.5% L.P. Interest 2.0% G.P. Interest and IDRs 1.4% L.P. Interest ____________________ (1) Includes Frank Semple, John Mollenkopf, Randy Nickerson, Donald Heppermann, Nancy Buese, Corwin Bromley and others. John Fox 180,924 MWE Common Units 5,382,537 MWP Shares Other Officers / Directors(1) 342,566 MWE Common Units 244,530 MWP Shares

3 Situation Analysis Timeline of Events February 21, 2007 – MWP announced the appointment of an independent committee of its Board of Directors to review a possible sale to, business combination with, or other potential restructuring alternatives involving MWE. April 13, 2007 – The Deal Committee received a proposal from MWE to acquire 100% of the stock of MWP for $52.50 per share, consisting of $12.50 per share of cash and $40.00 per share in newly issued MWE common units (1.166 MWE common units per MWP share). Deal Committee rejected this proposal. April 26, 2007 – Board resolution defining the role of the Deal Committee is expanded to include reviewing potential third party proposals, among other things. May 1, 2007 –The Deal Committee received a proposal from MWE to purchase 100% of the stock of MWP for $12.50 in cash and 1.28 MWE common units per MWP share, or $60.50 per MWP share based on MWE's closing unit price on April 30, 2007 of $37.50, which was an all time high. Deal Committee rejected this proposal. May 21, 2007 – The Deal Committee received a proposal from MWE to acquire 100% of the stock of MWP for $16.75 in cash and 1.34 MWE common units per MWP share, or $62.48 per MWP share based on MWE's closing unit price on May 21, 2007 of $34.13; a proposal characterized by MWE as “final” with an expiration of May 25, 2007.

4 Situation Analysis Timeline of Events (cont'd) May 25, 2007 – The Deal Committee sent a response letter to the conflicts committee (“Conflicts Committee”) of the Board of Directors of the general partner of MWE (the “MWE GP”) rejecting its May 21, 2007 proposal and countering with a value of $68.00 per MWP share. June 9, 2007 – The Deal Committee received proposal from the Conflicts Committee to acquire 100% of the stock of MWP for $20.00 in cash and 1.235 MWE common units per share, or $62.98 per MWP share based on MWE's closing unit price on June 8, 2007 of $34.80; a proposal characterized by the Conflicts Committee as “best”. June 10, 2007 – The Deal Committee extended a counter proposal (verbal) to the Conflicts Committee of 1.325 common units of MWE and $20.00 in cash per MWP share. June 11, 2007 – The Deal Committee received a verbal proposal from the Conflicts Committee to acquire 100% of the stock of MWP for $20.00 in cash and 1.285 MWE common units per share, or $64.65 per MWP share based MWE's closing unit price on June 11, 2007 of $34.75. July 22, 2007 – The Deal Committee received a reiteration of the previous proposal made on June 11, 2007 from the Conflicts Committee to acquire 100% of the stock of MWP for $20.00 in cash and 1.285 MWE common units per share, or $66.29 per MWP share based on MWE’s closing unit price on July 26, 2007 of $36.02.

5 Situation Analysis Timeline of Events (cont'd) Subsequent to the June 11 offer, MWP, MWE and their financial and legal advisors have primarily been addressing tax issues related to the transaction as well as negotiating terms of the Agreement summarized further herein. Since the offer of $20.00 in cash and 1.285 MWE common units per MWP share on June 11, the financial terms of the offer have not changed. However, the implied value of the offer has decreased from $64.65 to $60.97 per MWP share, or by approximately 5.7%, due to the MWE unit price decreasing from $34.75 to $31.88 During that period, the MWP share price has also declined from $56.62 per share to $50.29 per share As a result, the Merger/Redemption Consideration currently reflects a 21.2% premium to MWP’s share price as of August 31, 2007

6 Situation Analysis Recent Market Performance Since Merrill Lynch last presented to the Deal Committee on May 22, 2007, broader equity markets are relatively flat, despite significant interim volatility. This movement is largely attributable to credit market volatility and concerns The MLP equity market has experienced a substantial decline in recent weeks which many have attributed to hedge funds selling due to reduced access to leverage and the MLP equity market’s relative illiquidity resulting in the Alerian MLP index declining by 10.8% from its all time high on July 13, 2007 and 7.5% since May 21, 2007. The 10-year Treasury Yield has declined by 14 bps since May 21, 2007. Since May 21, MWP significantly underperformed the Alerian MLP Index declining by 16.8% while MWE has slightly outperformed the Alerian MLP index declining by 6.6%. February 21, March 30, % change May 21, % change August 31, % change 2007 2007 2/21 - 3/30 2007 3/30 - 5/21 2007 5/21 - 8/31 DJIA 12,738 12,354 (3.0%) 13,543 9.6% 13,358 (1.4%) Nasdaq 2,518 2,422 (3.8%) 2,579 6.5% 2,596 0.7% S&P 500 Energy Index 446 463 3.8% 523 12.8% 532 1.7% Alerian MLP Index 299 315 5.2% 330 4.9% 305 (7.5%) 10-Year Treasury Yield 4.69% 4.65% -4 bps 4.67% 2 bps 4.53% -14 bps Natural Gas Price ($/MMBtu at Henry Hub) $7.50 $7.50 0.0% $7.58 1.1% $5.56 (26.6%) WTI Crude Oil ($/Bbl) 59.47 65.87 10.8% 63.19 (4.1%) 71.71 13.5% MWP 58.30 62.00 6.3% 60.47 (2.5%) 50.29 (16.8%) MWE 31.05 35.50 14.3% 34.13 (3.9%) 31.88 (6.6%)

(3.2%) 7 Situation Analysis Relative Share/Unit Price Performance – Latest Twelve Months Relative Share/Unit Price Performance Relative Share/Unit Price Performance - Since February 21, 2007 86.5% 33.3% 16.6% 12.4% (13.7%) 2.7% 2.0% 1.1% 6.3% MWE Alerian Index S&P 500 MLP Comp Group(1) ____________________ (1) Includes Atlas Pipeline Partners, Copano Energy, L.L.C., Crosstex Energy, DCP Midstream Partners, Duncan Energy Partners LP, Eagle Rock Energy Parnters, Hiland Partners LC, Regency Energy Partners, Targa Resource Partners and Williams Partners. 60 80 100 120 140 160 180 200 220 240 260 9/1/06 10/6/06 11/10/06 12/15/06 1/19/07 2/23/07 3/30/07 5/4/07 6/8/07 7/13/07 8/13/07 60 80 100 120 140 2/21/07 3/14/07 4/4/07 4/25/07 5/16/07 6/6/07 6/27/07 7/18/07 8/4/07 8/21/07

8 Situation Analysis MLP Yield Comparison Since the February 21, 2007 announcement of a review of potential restructuring alternatives involving MWE, yields for MLPs in the 2% GP IDR tier have declined by an average of 66 bps while yields for MLPs currently above the 2% GP IDR tier have increased by over 18 bps on average. During this period, MWE’s yield has increased by 25 bps, in-line with MLPs in the 50% GP IDR tier. The result of such movement has been a wider yield disparity between MLPs in the 2% GP IDR tier and those in the 50% IDR tier GP IDR Current Yield Prior Change in MLP Tier Yield to Feb. 21 Ann. Yield Atlas Pipeline Partners 50.0% 7.5% 7.0% 49 bps Crosstex Energy 50.0% 6.4% 6.0% 46 bps DCP Midstream Partners 50.0% 4.7% 5.0% -31 bps Energy Transfer Partners 50.0% 6.2% 6.0% 18 bps Hiland Partners 50.0% 5.9% 5.1% 79 bps Kinder Morgan Energy Partners 50.0% 6.8% 6.6% 16 bps Magellan Midstream Partners 50.0% 5.9% 5.8% 2 bps ONEOK Partners 50.0% 6.2% 6.1% 18 bps Plains All American 50.0% 5.8% 5.9% -18 bps Sunoco Logistics 50.0% 6.2% 5.7% 50 bps Buckeye Partners 45.0% 6.6% 6.3% 28 bps Mean 6.2% 6.0% 23 bps Median 6.2% 6.0% 18 bps Enbridge Energy Partners 25.0% 7.3% 7.0% 22 bps Enterprise Products Partners 25.0% 6.5% 6.3% 21 bps Holly Energy Partners 25.0% 6.0% 6.0% 2 bps Martin Midstream 25.0% 6.9% 6.9% -6 bps NuStar Energy L.P. 25.0% 6.1% 5.6% 49 bps TC PipeLines 25.0% 7.1% 7.0% 9 bps TEPPCO Partners 25.0% 6.8% 6.5% 37 bps Williams Partners 25.0% 4.7% 4.6% 10 bps Boardwalk Pipeline Partners 15.0% 5.3% 4.8% 50 bps Global Partners LP 15.0% 5.9% 6.7% -80 bps Transmontaigne Partners 15.0% 6.2% 5.8% 32 bps Mean 6.3% 6.1% 13 bps Median 6.2% 6.3% 21 bps Duncan Energy Partners 2.0% 6.7% 6.7% -3 bps Eagle Rock Energy Partners 2.0% 6.6% 7.2% -61 bps Genesis Energy LP 2.0% 3.7% 4.6% -91 bps Regency Energy Partners 2.0% 4.8% 5.5% -79 bps Targa Resource Partners 2.0% 4.5% 5.6% -110 bps Exterran Partners 2.0% 4.1% 4.8% -71 bps Copano Energy, L.L.C. NA 4.5% 5.0% -51 bps Mean 5.0% 5.6% -66 bps Median 4.5% 5.5% -71 bps MWE 50.0% 6.6% 6.4% 25 bps

9 Situation Analysis GP Yield Comparison ____________________ (1) Note: Denotes that the GP is held in a C-Corporation. (1) Since February 21, 2007, GP yields have declined on average by 70 bps. During that period, MWP’s yield has increased by 78 bps from 2.08% to 2.86%, moving MWP from having the lowest GP yield to having the third lowest yield among all public GPs. GP IDR Current Yield Prior Change in GP Tier Yield to Feb. 21 Ann. Yield Alliance Holdings GP, L.P. 50.0% 4.21% 4.60% -39 bps Atlas Pipeline Holdings, L.P. 50.0% 2.56% 3.98% -142 bps Buckeye GP Holdings, L.P. 45.0% 3.18% 5.22% -203 bps Crosstex Energy Inc. (1) 50.0% 2.80% 2.90% -10 bps Energy Transfer Equity L.P. 50.0% 4.05% 4.51% -46 bps Enterprise GP Holdings L.P. 25.0% 3.97% 4.09% -12 bps Hiland Holdings GP, L.P. 50.0% 2.91% 2.90% 1 bps Inergy Holdings, L.P. 50.0% 4.54% 5.00% -47 bps Magellan Midstream Holdings, L.P. 50.0% 3.90% 4.48% -58 bps Nustar GP Holdings, LLC 25.0% 4.16% 5.06% -90 bps Penn Virginia GP, L.P. 50.0% 3.56% 4.79% -122 bps Mean 3.62% 4.32% -70 bps Median 3.90% 4.51% -47 bps MWP (1) 50.0% 2.86% 2.08% 78 bps

Overview of Transaction

10 Overview of Merger/Redemption Consideration The following sets forth an overview of the Merger/Redemption Consideration. Overview of Transaction ____________________ (1) Based on 30 day MWE VWAP of $33.58. (2) GP cash flows taxed at a 37.7%tax rate. MWE Price at 08/31/2007 $31.88 Proposed Exchange Ratio 1.285 Value in MWE Units $40.97 Cash Consideration per MWP Common Share from MWP 20.00 Implied Merger/Redemption Consideration per MWP Common Share $60.97 MWP Shares Outstanding 12.1 Implied Total Aggregate Consideration $734.8 Less: Cash (52.3) Implied Total Consideration $682.5 Implied Merger/Redemption Consideration per MWP Common Share Premium: Price Premium Current $50.29 21.2% Prior 5 Day Average 50.75 20.1% 30 Day Average 52.62 15.9% 60 Day Average 54.87 11.1% Implied Multiple to Current GP Run-Rate Distribution: Implied Total Consideration $682.5 (46.0) (1) (166.9) Implied Value of 89.7% interest in GP $469.6 Current After-tax General Partner Run-Rate Distribution to 89.7% Interest (2) $16.0 Implied Multiple of GP Cash Flow 29.3x Less: Assumed Value of MWE Units Owned by MWP Less: Assumed Value of Frac Spread Business

August 28, 2007: Proposal from MWE Deal Committee representing $60.48 per MWP Share 11 LTM MWP Share Price Performance Overview of Transaction Implied Merger/Redemption Consideration: $60.97 per MWP share April 13, 2007: Initial proposal representing $52.50 per MWP Share May 1, 2007: Second proposal representing $60.50 per MWP Share May 21, 2007: Third proposal representing $62.48 per MWP Share June 9, 2007: Fourth proposal representing $62.98 per MWP Share $20.00 $25.00 $30.00 $35.00 $40.00 $45.00 $50.00 $55.00 $60.00 $65.00 $70.00 9/1/2006 11/2/2006 1/3/2007 3/6/2007 5/7/2007 7/8/2007 MWP Share Price

12 MWP/MWE LTM Historical Trading Ratio Overview of Transaction 1.046x = LTM Average Adjusted Exchange Ratio(1) 1.557x = LTM Average Unadjusted Exchange Ratio 1.285x = Merger/Redemption Consideration Ratio Adjusted Exchange Ratio(1) Unadjusted Exchange Ratio ____________________ (1) Adjusted for MWE units equaling approximately 67.2% of total consideration. The following sets forth the latest twelve months MWP/MWE trading ratio both on: (i) an unadjusted basis as well as (ii) an adjusted basis with MWE units equaling approximately 67.2% of total consideration representing the MWE unit portion of the Merger/Redemption Consideration based on MWE’s closing unit price of $31.88 on August 31, 2007. 0.50x 0.75x 1.00x 1.25x 1.50x 1.75x 2.00x 9/1/06 10/16/06 11/28/06 1/10/07 2/22/07 4/6/07 5/21/07 7/3/07 8/9/07

13 Overview of Transaction (in thousands) MWP – MWE Trading and Liquidity Analysis Daily Trading Summary MWP 30-Day Avg. 60-Day Avg. 90-Day Avg. 180-Day Avg. LTM Avg. Daily Volume 44 39 37 47 41 Float 6,370 6,370 6,370 6,370 6,370 % of Float 0.69% 0.60% 0.58% 0.74% 0.65% Daily Trading Value $2,303 $2,114 $2,076 $2,641 $2,036 % of Current Market Value 0.38% 0.35% 0.34% 0.44% 0.34% MWE Daily Volume 106 91 87 91 88 Float 31,039 31,039 31,039 28,175 28,843 % of Float 0.34% 0.29% 0.28% 0.29% 0.28% Daily Trading Value $3,575 $3,142 $3,016 $3,043 $2,753 % of Current Market Value 0.32% 0.28% 0.27% 0.27% 0.24%

14 Overview of Key Terms of the Agreement Overview of Transaction Item Comment Consideration $20.00 per share of cash consideration to come from MWP in a redemption plus 1.285 units of MWE for each outstanding share of MWP ($6 0 . 97 as of close on August 31 , 2007) Structure 2 - step transaction: (i) Redemption of cash elec ting shares followed immediately by (ii) the merger of the sub of MWE with and into MWP , with MWP surviving as a wholly - owned subsidiary of MWE. U nit portion of consideration tax - free to MWP shareholders Voting Agreements John Fox and MWHC Holding, Inc. Governance 3 existing MWP directors on pro forma board , 2 of whom must be independent Go Shop Provision /Fiduciary Out 30 day go shop period , including a reduced termination fee of $7.5 million (~ 1% of equity value ) , if during that period the Deal Committ ee recommends a superior proposal that is subsequently approved by the Board of MWP or at any time if MWP does a deal with an excluded party – After 30 days if deal not with an excluded party , termination fee increases to $15.0 million (~ 2% of equity value ) Termination · By mutual agreement · If transaction has not closed by February 2 7 , 2008 · F ailure to obtain government or equity holder approval · Upon a change in R ecommendation by MWP or MWE (but only by MWP with respect to its C I R in connection with a Super ior Proposal) Conditions to Closing · Equity holder vote by both MWP and MWE · Governmental approvals (e.g. HSR) · Effective registration statement · Tax opinions to both MWP and MWE; no change in tax laws · Valuation opinion for exchange of MWP’s MWE units and ge neral partner of the economic interest in its 2% GP inte rest in MWE and IDRs for Class A Common Units Other Customary terms and conditions

Summary Valuation

15 Summary Valuation Overview The materials herein contain a summary valuation of MWP and MWE prepared by Merrill Lynch based on financial projections for MWE and MWP as provided by management and adjusted by Merrill Lynch and analyzed based on various growth capital expenditures/acquisitions sensitivities. To derive a valuation for MWP, Merrill Lynch has utilized a sum-of-the-parts valuation approach, whereby MWP's value consists of the sum of the values of its primary assets: (i) 89.7% MWE GP interest; (ii) 4.9 million MWE LP units; (iii) Frac Spread Business; and (iv) net cash projected to be on hand as of December 31, 2007 A discounted cash flow analysis ("DCF Analysis"); a comparable company trading analysis ("CompCo Analysis") and a Comparable Acquisition Analysis ("CompAcq Analysis") have been utilized to value the 89.7% MWE GP interest MWP's 4.9 million MWE LP units have been valued utilizing a DCF Analysis, CompCo Analysis and a CompAcq Analysis, assuming a tax liability based on a negative $8.90 tax basis per MWE unit and a 37.7% tax rate upon sale Given the lack of publicly-traded companies comparable to the Frac Spread Business and a lack of historical acquisitions of businesses similar to the Frac Spread Business, the Frac Spread Business has been valued utilizing a DCF Analysis

16 Summary Valuation Assumptions Overview of MWE Financial Projections The MWE projections utilized for the analysis herein are based on MWE management estimates as of July 2007 as adjusted for the following assumptions: 2008E – 2012E commodity pricing based on the NYMEX strip as of August 31, 2007 As an adjustment to management estimates of $50 million of growth capital expenditures/acquisitions throughout the forecast period, Merrill Lynch has assumed $100 million of incremental annual growth capital expenditures/acquisitions for a total of $150 million of annual growth capital expenditures/acquisitions throughout the forecast period Growth capital expenditures/acquisitions assumed to be completed at 8.0x multiple of current year EBITDA Maintenance capital expenditures for growth capital expenditures/acquisitions are assumed to equal 4% of growth capital expenditures/acquisitions EBITDA Growth capital expenditures/acquisitions financed 60% with equity and 40% with debt Weighted average interest rate of 8.25% Units issued at then current year distribution and an assumed yield of 6.50% 2008E 2009E 2010E 2011E 2012E Crude Oil ($/Bbl) $70.50 $69.20 $68.45 $68.13 $68.05 Natural Gas ($/MMBtu) 7.68 8.16 8.01 7.80 7.60

17 Summary Valuation Historical Growth Capital Expenditures/Acquisitions Overview of MWE Financial Projections (cont’d) Acquisitions $809 million in acquisitions since IPO Growth Capital Expenditures $189 million in organic growth projects through 2006, with ~$332 million currently targeted for 2007 Average Common Unit Yield GP Incentive Distribution Tier Average All-In Cash Cost of Equity(2) 5.3% 2.0% 5.5% 7.5% 25.0% 7.8% 6.8% 50.0% 7.5% 6.4% 50.0% 7.5% 7.5% 50.0% 9.7% 6.4%(1) 50.0% 8.7% ____________________ (1) As of August 31, 2007. (2) Defined as current distribution to LP unitholders and GP distributions (including incentive distribution rights) divided by equity market value. $0 $0 $15 $111 $243 $440 $0 $100 $200 $300 $400 $500 2002 2003 2004 2005 2006 2007 YTD (dollars in millions) $0 $2 $29 $69 $89 ~$332 $0 $100 $200 $300 $400 2002 2003 2004 2005 2006 2007E (dollars in millions)

18 Summary Valuation Summary Results (dollars in thousands, except per unit amounts) ____________________ (1) Other non-cash items include: (i) Starfish Cash Flow in Excess of Earnings of $3,302 and $1,821 in 2007E and 2008E, respectively and $0 thereafter, (ii) Phantom Unit Compensation of $15,295 in 2007E through 2012E, (iii) $6,642 of other in 2007E and $0 thereafter and (iv) taxes of $19 in 2007E and $0 thereafter. (2) EBITDA includes other non-cash items. Overview of MWE Financial Projections (cont’d) Years Ending December 31, '07E - '12E 2007E 2008E 2009E 2010E 2011E 2012E CAGR EBITDA $158,188 $191,652 $206,358 $196,706 $199,028 $199,877 Plus: EBITDA from Incremental Growth CapEx/Acquisitions 0 9,375 28,125 46,875 65,625 84,375 Total EBITDA $158,188 $201,027 $234,483 $243,581 $264,653 $284,252 12.4% Less: Base Cash Interest Expense (36,253) (50,488) (51,388) (52,920) (52,146) (51,177) Less: Interest Expense from Incremental Growth CapEx/Acquisitions 0 (2,475) (7,425) (12,375) (17,325) (22,275) Less: Base Maintenance Capital Expenditures (4,688) (4,191) (6,306) (4,666) (4,666) (4,666) Less: Maintenance CapEx from Incremental Growth CapEx/Acquisitions 0 (375) (1,125) (1,875) (2,625) (3,375) Plus: Other Non-Cash Items (1) 25,220 17,116 15,295 15,295 15,295 15,295 Distributable Cash Flow 142,466 160,615 183,535 187,041 203,186 218,054 8.9% Less: Cash Withheld for Distribution Coverage (35,813) (31,448) (36,936) (29,028) (32,243) (34,448) Cash Flow Distributed 106,653 129,166 146,598 158,012 170,943 183,606 Less: Cash Distributed to General Partner (28,120) (36,685) (43,585) (47,549) (52,293) (56,933) Cash Flow Distributed to Limited Partners $78,533 $92,481 $103,013 $110,463 $118,650 $126,673 10.0% Avergage LP Units Outstanding 36,858 40,772 43,428 45,977 48,494 50,967 Distribution per LP Unit $2.13 $2.27 $2.37 $2.40 $2.45 $2.49 3.1% Distribution per LP Unit Excluding Incremental Growth CapEx/Acquisitions 2.13 2.25 2.33 2.32 2.34 2.36 2.1% Distribution Coverage 1.34x 1.24x 1.25x 1.18x 1.19x 1.19x Distributable Cash Flow per Unit $2.61 $2.62 $2.75 $2.65 $2.69 $2.72 0.9% Assumed Yield 6.50% 6.50% 6.50% 6.50% 6.50% 6.50% Implied Unit Price $32.78 $34.90 $36.49 $36.96 $37.64 $38.24 Growth Capital Expenditures/Acquisitions $332,423 $185,962 $222,623 $170,859 $170,120 $167,534 Total Debt $644,798 $702,096 $797,942 $852,557 $902,651 $945,727 Total Debt/EBITDA (2) 3.5x 3.2x 3.2x 3.3x 3.2x 3.2x

19 Summary Valuation Assumptions Projections based on previously outlined MWE projections and MWP management estimates. 89.7% of MWE GP owned by MWP Same commodity pricing assumptions as assumed for MWE, including MWP hedges currently in place No projected capital expenditures during the forecast period Tax rate of 37.7% No tax shield on LP unit distributions GP distributions are 100% taxable Overview of MWP Financial Projections

20 Summary Valuation Summary Results (dollars in thousands) Overview of MWP Financial Projections (cont’d) Years Ending December 31, '07E - '12E 2007E 2008E 2009E 2010E 2011E 2012E CAGR Frac Spread Business: Frac Spread $26,952 $22,351 $15,297 $16,366 $16,462 $18,459 Less: SG&A (21,908) (20,306) (20,712) (21,127) (21,549) (21,980) Plus: Non-Cash SG&A 8,634 8,807 8,983 9,162 9,346 9,533 Operating Income 13,678 10,852 3,567 4,402 4,259 6,011 (15.2%) Less: Depreciation (1,513) (266) 0 0 0 0 Less: Amortization (312) (542) (542) (542) (542) (542) Plus: Interest Income 616 2,610 3,157 3,674 4,260 4,887 Taxable Income $12,469 $12,654 $6,183 $7,534 $7,977 $10,357 (3.6%) Distributions from MWE LP Units: Total Distributions $10,585 $11,262 $11,787 $11,938 $12,156 $12,348 Tax Shield 0.0% 0.0% 0.0% 0.0% 0.0% 0.0% Taxable Income $10,585 $11,262 $11,787 $11,938 $12,156 $12,348 3.1% Distributions from MWE GP: Total Distributions (89.7%) $25,224 $32,907 $39,096 $42,651 $46,907 $51,069 Tax Shield 0.0% 0.0% 0.0% 0.0% 0.0% 0.0% Taxable Income $25,224 $32,907 $39,096 $42,651 $46,907 $51,069 15.2% Total Taxable Income $48,278 $56,823 $57,066 $62,124 $67,039 $73,774 Tax Rate 37.7% 37.7% 37.7% 37.7% 37.7% 37.7% Total Cash Taxes $18,201 $21,422 $21,514 $23,421 $25,274 $27,813 Plus: DD&A 1,825 808 542 542 542 542 MWP Distributable Cash Flow $31,902 $36,208 $36,094 $39,245 $42,307 $46,503 7.8%

21 Summary Valuation Comparison of Merrill Lynch and Management Projections The following pages provide a comparison of the Merrill Lynch projections utilized for MWE and MWP herein and the MWE and MWP projections as provided to Merrill Lynch in April 2007, June 2007 and July 2007. The primary differences between these projections are set forth below: Merrill Lynch has updated commodity pricing for strip pricing as of August 31, 2007 Merrill Lynch has assumed additional growth capital expenditures/acquisitions of $100 million throughout the forecast period Merrill Lynch has assumed an MWE distribution yield of 6.50% throughout the forecast period versus MWE management’s assumption of 6.25%

22 Summary Valuation (dollars in thousands, except per unit amounts) Comparison of Merrill Lynch and Management Projections (cont'd) Merrill Lynch Projections MWE: 2007E 2008E 2009E 2010E 2011E 2012E EBITDA $158,188 $201,027 $234,483 $243,581 $264,653 $284,252 Distributable Cash Flow 142,466 160,615 183,535 187,041 203,186 218,054 Distribution per LP Unit $2.13 $2.27 $2.37 $2.40 $2.45 $2.49 GP Distribution $28,120 $36,685 $43,585 $47,549 $52,293 $56,933 MWP: Frac Spread Business Operating Income (Pre - SG&A) $26,952 $22,351 $15,297 $16,366 $16,462 $18,459 Pre-Tax Distributions from MWE Units 10,585 11,262 11,787 11,938 12,156 12,348 Pre-Tax 89.7% MWE GP Distributions 25,224 32,907 39,096 42,651 46,907 51,069 Management Projections April 2007 June 2007 July 2007 MWE: 2007E 2008E 2009E 2010E 2011E 2012E 2007E 2008E 2009E 2010E 2011E 2012E 2007E 2008E 2009E 2010E 2011E 2012E EBITDA $163,919 $188,890 $208,265 $224,089 $245,032 $267,060 $155,542 $185,943 $196,722 $200,950 $208,492 $216,546 $158,188 $198,733 $215,972 $213,952 $223,280 $231,601 Distributable Cash Flow 137,290 145,014 157,021 167,641 183,724 201,275 137,147 144,565 149,538 150,662 156,205 162,426 142,457 159,913 170,416 166,428 174,390 181,648 Distribution per LP Unit $2.12 $2.25 $2.32 $2.35 $2.38 $2.43 $2.12 $2.31 $2.38 $2.38 $2.41 $2.44 $2.13 $2.30 $2.36 $2.38 $2.42 $2.46 GP Distribution $27,427 $33,214 $38,045 $42,082 $46,419 $51,999 $27,464 $34,829 $38,233 $39,055 $41,072 $43,102 $28,120 $37,092 $40,289 $41,940 $44,454 $47,018 MWP: Frac Spread Business Operating Income (Pre - SG&A) $25,208 $13,582 $14,972 $15,523 $14,023 $11,558 $31,374 $17,714 $14,445 $14,912 $15,533 $15,447 $27,012 $22,125 $16,582 $19,963 $21,433 $20,012 Pre-Tax Distributions from MWE Units 10,471 11,113 11,458 11,607 11,755 12,002 10,472 11,409 11,755 11,755 11,903 12,051 10,585 11,426 11,724 11,823 12,022 12,221 Pre-Tax 89.7% MWE GP Distributions 24,602 29,793 34,126 37,748 41,638 46,643 24,635 31,242 34,295 35,032 36,841 38,663 25,224 33,272 36,140 37,620 39,875 42,175 Difference Between Merrill Lynch & Management Projections April 2007 June 2007 July 2007 MWE: 2007E 2008E 2009E 2010E 2011E 2012E 2007E 2008E 2009E 2010E 2011E 2012E 2007E 2008E 2009E 2010E 2011E 2012E EBITDA ($5,732) $12,137 $26,218 $19,492 $19,621 $17,192 $2,645 $15,084 $37,761 $42,631 $56,161 $67,705 $0 $2,294 $18,511 $29,629 $41,374 $52,651 Distributable Cash Flow 5,177 15,601 26,514 19,400 19,463 16,779 5,319 16,049 33,996 36,379 46,981 55,628 9 701 13,119 20,612 28,796 36,406 Distribution per LP Unit $0.01 $0.02 $0.05 $0.05 $0.07 $0.06 $0.01 ($0.04) ($0.01) $0.02 $0.04 $0.05 $0.00 ($0.03) $0.01 $0.02 $0.03 $0.03 GP Distribution $693 $3,471 $5,540 $5,467 $5,873 $4,934 $656 $1,856 $5,353 $8,494 $11,221 $13,831 $0 ($407) $3,296 $5,609 $7,839 $9,915 MWP: Frac Spread Business Operating Income (Pre - SG&A) $1,744 $8,769 $325 $843 $2,439 $6,901 ($4,422) $4,637 $852 $1,454 $929 $3,012 ($60) $226 ($1,285) ($3,597) ($4,971) ($1,553) Pre-Tax Distributions from MWE Units 114 149 329 332 401 347 113 (147) 32 184 253 297 0 (164) 63 115 134 128 Pre-Tax 89.7% MWE GP Distributions 622 3,113 4,970 4,904 5,268 4,426 588 1,665 4,801 7,619 10,065 12,406 0 (365) 2,956 5,031 7,031 8,894

MWE GP Distribution (dollars in thousands) 23 MWE EBITDA (dollars in thousands) MWE Distribution per LP Unit Frac Spread Business Operating Income (dollars in thousands) Summary Valuation Merrill Lynch Projections Management (April 2007) Management (June 2007) Management (July 2007) Comparison of Merrill Lynch and Management Projections (cont'd) $0 $50,000 $100,000 $150,000 $200,000 $250,000 $300,000 2007E 2008E 2009E 2010E 2011E 2012E $1.90 $2.00 $2.10 $2.20 $2.30 $2.40 $2.50 $2.60 2007E 2008E 2009E 2010E 2011E 2012E $0 $10,000 $20,000 $30,000 $40,000 $50,000 $60,000 2007E 2008E 2009E 2010E 2011E 2012E $0 $5,000 $10,000 $15,000 $20,000 $25,000 $30,000 $35,000 2007E 2008E 2009E 2010E 2011E 2012E

24 Summary Valuation MWP Summary Value per Share Summary Results Current Price: $50.29 Implied Merger/Redemption Consideration: $60.97 $33.63 $47.73 $46.90 $44.91 $76.44 $72.29 $0.00 $10.00 $20.00 $30.00 $40.00 $50.00 $60.00 $70.00 $80.00 $90.00 DCF Analysis CompCo Analysis CompAcq Analysis Price per MWP Share

25 Summary Valuation MWE Summary Value per Unit Summary Results Current Price: $31.88 $31.95 $32.00 $25.00 $49.74 $55.00 $43.00 $0.00 $10.00 $20.00 $30.00 $40.00 $50.00 $60.00 DCF Analysis CompCo Analysis CompAcq Analysis Price per MWE Unit

26 Summary Valuation Implied Exchange Ratios Based on Summary Valuation Summary Results Summary Valuation Comparison MWP MWE Implied MWP/MWE Implied MWP/MWE Relevant Equity Relevant Equity Exchange Ratio Exchange Ratio Value Range Value Range if 100% Equity if 67.2% Equity Methodology ($ per Share) ($ per Unit) Consideration Consideration DCF Analysis $46.90 - $72.29 $31.95 - $49.74 0.94x - 2.26x 0.63x - 1.52x CompCo Analysis 47.73 - 76.44 32.00 - 55.00 0.87 - 2.39 0.58 - 1.61 CompAcq Analysis 33.63 - 44.91 25.00 - 43.00 0.78 - 1.80 0.53 - 1.21 Implied Merger/ Redemption Implied Merger/ Redemption Consideration $60.97 Consideration Ratio 1.285x

27 Summary Valuation Overview The materials herein contain a summary valuation of MWP and MWE prepared by Merrill Lynch based on financial projections for MWE and MWP as provided by management and adjusted by Merrill Lynch and analyzed based on various growth capital expenditures/acquisitions sensitivities. To derive a valuation for MWP, Merrill Lynch has utilized a sum-of-the-parts valuation approach, whereby MWP's value consists of the sum of the values of its primary assets: (i) 89.7% MWE GP interest; (ii) 4.9 million MWE LP units; (iii) Frac Spread Business; and (iv) net cash on hand A discounted cash flow analysis ("DCF Analysis"); a comparable company trading analysis ("CompCo Analysis") and a Comparable Acquisition Analysis ("CompAcq Analysis") have been utilized to value the 89.7% MWE GP interest DCF Analysis: Based on projected cash flows to the 89.7% MWE GP Interest for the next five years and applying a terminal multiple to after-tax MWE GP cash flow in the terminal year (ranging from 16.0x to 21.0x), Merrill Lynch analyzed the value of the 89.7% MWE GP Interest utilizing various annual growth capital expenditures/acquisitions levels at MWE (ranging from $100 million to $200 million) and appropriate equity discount rates (ranging from 7.0% to 9.0%) CompCo Analysis: Based on the annualized 2007 Q2 after-tax distribution to the 89.7% MWE GP Interest, Merrill Lynch applied a relevant yield range (2.50% to 4.50%) and a relevant cash flow multiple range (25.0x to 45.0x) CompAcq Analysis: Based on the annualized 2007 Q2 after-tax distributions to the 89.7% MWE GP Interest, Merrill Lynch applied a relevant cash flow multiple range (16.0x to 21.0x)

28 Summary Valuation Overview (cont'd) MWP's 4.9 million MWE LP units have been valued utilizing a DCF Analysis, CompCo Analysis and a CompAcq Analysis, assuming a tax liability based on a negative $8.90 tax basis per MWE unit and a 37.7% tax rate upon sale DCF Analysis: Based on the projected distributions per MWE unit over the next five years and applying a terminal yield to the distribution per MWE unit in the terminal year (ranging from 4.50% to 7.00%), Merrill Lynch analyzed the value of the MWE LP units utilizing various annual growth capital expenditures/acquisitions levels at MWE (ranging from $100 million to $200 million) and appropriate equity discount rates (ranging from 7.00% to 9.00%) CompCo Analysis: Based on the 2007 Q2 annualized and 2008E distributions per MWE LP unit, Merrill Lynch applied a relevant yield range of 4.50% to 7.00% and 5.50% to 8.00%, respectively. Based on projected 2007E MWE EBITDA and 2008E MWE EBITDA, Merrill Lynch applied relevant multiple ranges of 13.0x to 17.0x and 8.5x to 12.0x, respectively, and subtracted the net debt as of 6/30/07 to derive an equity value and then divided the equity value by the current MWE units outstanding CompAcq Analysis: Based on LTM EBITDA as of 6/30/07 and projected 2007E MWE EBITDA, Merrill Lynch applied a relevant multiple range of 9.5x to 13.5x and 9.0x to 13.0x, respectively, and subtracted the net debt as of 6/30/07 to derive an equity value and then divided the equity value by the current MWE units outstanding Given the lack of publicly-traded companies comparable to the Frac Spread Business and a lack of historical acquisitions of businesses similar to the Frac Spread Business, the Frac Spread Business has been valued utilizing a DCF Analysis Net cash projected to be on hand as of December 31, 2007 has been included at face value

Discounted Cash Flow Analysis

29 Discounted Cash Flow Analysis Summary Sum-of-the-Parts ____________________ (1) Based on fully-diluted MWP shares of approximately 12.1 million. Current Equity Value: $606,163 Implied Merger/Redemption Consideration: $734,842 $565,343 $43,000 $80,000 $390,000 $871,343 $52,343 $49,000 $140,000 $630,000 $0 $100,000 $200,000 $300,000 $400,000 $500,000 $600,000 $700,000 $800,000 $900,000 $1,000,000 89.7% of MWE GP Interest MWE LP Units Frac Spread Business Net Cash Total MWP Implied Equity Value (dollars in thousands) Value Per MWP Share (1) $32.36 - $52.27 $6.64 - $11.62 $3.57 - $4.07 $4.34 $46.90 - $72.29

30 Discounted Cash Flow Analysis (dollars in thousands) 89.7% of MWE GP Interest 9.0% Discount Rate 8.0% Discount Rate 7.0% Discount Rate Years Ending December 31, 2008E 2009E 2010E 2011E 2012E Pre-Tax MWE GP Distribution (89.7%) $32,907 $39,096 $42,651 $46,907 $51,069 (12,406) (14,739) (16,080) (17,684) (19,253) After-Tax MWE GP Distribution $20,501 $24,357 $26,572 $29,223 $31,816 (1,800) (1,800) (1,800) (1,800) (1,800) Total GP Cash Flow $18,701 $22,557 $24,772 $27,423 $30,016 $507,771 16.0x 17.0x 18.0x 19.0x 20.0x 21.0x $0 $307,977 $322,149 $336,321 $350,494 $364,666 $378,838 50,000 346,979 363,319 379,659 395,999 412,339 428,679 100,000 386,207 404,728 423,248 441,768 460,288 478,809 150,000 425,058 445,736 466,414 487,093 507,771 528,449 200,000 463,822 486,655 509,487 532,320 555,153 577,986 250,000 502,707 527,702 552,697 577,692 602,687 627,682 300,000 541,705 568,869 596,033 623,197 650,361 677,525 Terminal Multiple of After-Tax GP Cash Flow Annual Acquisitions/Growth Capital Expenditures at MWE 16.0x 17.0x 18.0x 19.0x 20.0x 21.0x $320,862 $335,703 $350,544 $365,384 $380,225 $395,066 361,669 378,779 395,890 413,001 430,111 447,222 402,712 422,106 441,499 460,893 480,287 499,680 443,359 465,013 486,666 508,320 529,973 551,627 483,916 507,826 531,736 555,645 579,555 603,464 524,600 550,774 576,948 603,122 629,296 655,470 565,403 593,848 622,293 650,738 679,184 707,629 Terminal Multiple of After-Tax GP Cash Flow 16.0x 17.0x 18.0x 19.0x 20.0x 21.0x $334,454 $350,001 $365,548 $381,096 $396,643 $412,190 377,166 395,091 413,017 430,942 448,867 466,793 420,127 440,444 460,761 481,078 501,395 521,712 462,673 485,357 508,041 530,726 553,410 576,095 505,124 530,172 555,220 580,268 605,316 630,364 547,709 575,129 602,549 629,969 657,389 684,809 590,418 620,217 650,017 679,816 709,616 739,415 Terminal Multiple of After-Tax GP Cash Flow Relevant Value Range $390,000 - $630,000 Less: Equity Contribution on MWE Unit Issuance Less: Taxes at 37.7%

31 Discounted Cash Flow Analysis (dollars and units in thousands, except per unit amounts) MWE LP Units 9.0% Discount Rate 8.0% Discount Rate 7.0% Discount Rate ____________________ (1) Relevant value to MWP assumes a current tax liability upon sale of negative $8.90 and a tax rate of 37.7%. Years Ending December 31, 2008E 2009E 2010E 2011E 2012E $2.27 $2.37 $2.40 $2.45 $2.49 Terminal MWE LP Unit Distribution Yield 41.59 7.00% 6.50% 6.00% 5.50% 5.00% 4.50% $0 $30.92 $32.60 $34.57 $36.89 $39.68 $43.08 50,000 31.46 33.18 35.19 37.56 40.40 43.88 100,000 31.95 33.69 35.74 38.15 41.04 44.58 150,000 32.36 34.13 36.20 38.65 41.59 45.18 200,000 32.72 34.52 36.62 39.09 42.07 45.70 250,000 33.05 34.87 36.99 39.49 42.50 46.18 300,000 33.35 35.19 37.33 39.86 42.90 46.61 350,000 33.63 35.48 37.64 40.20 43.26 47.01 Annual Acquisitions/Growth Capital Expenditures at MWE Terminal MWE LP Unit Distribution Yield 7.00% 6.50% 6.00% 5.50% 5.00% 4.50% $32.19 $33.95 $36.01 $38.44 $41.36 $44.93 32.76 34.56 36.66 39.14 42.12 45.76 33.27 35.10 37.23 39.76 42.79 46.50 33.70 35.55 37.72 40.29 43.36 47.12 34.08 35.96 38.15 40.75 43.86 47.67 34.42 36.32 38.54 41.17 44.32 48.17 34.73 36.66 38.90 41.55 44.73 48.62 35.02 36.96 39.22 41.90 45.11 49.03 Terminal MWE LP Unit Distribution Yield 7.00% 6.50% 6.00% 5.50% 5.00% 4.50% $33.53 $35.38 $37.54 $40.08 $43.14 $46.88 34.13 36.02 38.22 40.82 43.94 47.75 34.66 36.58 38.82 41.46 44.64 48.52 35.11 37.05 39.33 42.01 45.23 49.17 35.50 37.48 39.78 42.49 45.76 49.74 35.86 37.86 40.18 42.93 46.23 50.26 36.19 38.20 40.55 43.33 46.66 50.74 36.49 38.52 40.90 43.70 47.06 51.17 Relevant MWE Unit Value Range $31.95 - $49.74 L.P. Units Owned by MWP 4,969 Aggregate Pre-Tax Value $158,753 - $247,206 Less: Tax Liability Upon Sale (1) (76,524) - (109,871) After-Tax Value $82,229 - $137,335 Relevant Value to MWP $80,000 - $140,000 Distribution per LP Unit

32 Discounted Cash Flow Analysis Assumptions Frac Spread Business In performing a discounted cash flow analysis of MWP's Frac Spread Business, Merrill Lynch has utilized the following assumptions: Operating assumptions as provided by management Strip commodity pricing as of August 31, 2007 Annual SG&A expenses of $5 million, which Merrill Lynch believes is a reasonable level to operate the Frac Spread Business on a stand alone basis A tax rate of 37.7% Discount rate increasing from 6.6% in 2008E to 20.0% in 2012E with the discount rate increasing as the surety of cash flows decreases 2008E discount rate equal to LIBOR + 100 bps based on strong liquidity in short-term NGL hedging market Discount rates in 2009E through 2011E based on sequential increase between first year discount rate and equity discount rate of 20.0% utilized in 2012E to reflect diminishing liquidity in NGL hedging market in outer years Terminal value based on the perpetuity growth method with growth rates ranging from (1.0%) to 1.0% and discount rates ranging from 17.5% to 22.5% Although the agreement between MWP and MWE that provides for the cash flow of the Frac Spread Business is set to expire in 2012, management has indicated through discussions to Merrill Lynch that the agreement would likely be renewed but subject to renegotiation Discount rates chosen to reflect equity rate of return given the riskiness of commodity price forecasts and illiquidity of the NGL hedging market in the outer years

33 Discounted Cash Flow Analysis Results (dollars in thousands) Frac Spread Business (cont'd) Years Ending December 31, 2008E 2009E 2010E 2011E 2012E Frac Spread $22,351 $15,297 $16,366 $16,462 $18,459 (5,000) (5,000) (5,000) (5,000) (5,000) Operating Income $17,351 $10,297 $11,366 $11,462 $13,459 (266) 0 0 0 0 (542) (542) (542) (542) (542) Plus: Interest Income 2,610 3,157 3,674 4,260 4,887 Taxable Income $16,544 $9,755 $10,824 $10,920 $12,917 (6,237) (3,678) (4,081) (4,117) (4,870) After-Tax Income $10,307 $6,078 $6,744 $6,803 $8,047 266 0 0 0 0 542 542 542 542 542 After-Tax Cash Flow $11,114 $6,619 $7,285 $7,345 $8,589 Discount Rate 6.60% 9.95% 13.30% 16.65% 20.00% $10,426 $5,475 $5,009 $3,967 $3,452 Present Value of Discounted Cash Flows $28,329 $17,259 (2.0%) (1.0%) 0.0% 1.0% 2.0% (2.0%) (1.0%) 0.0% 1.0% 2.0% 15.0% $19,898 $21,358 $23,012 $24,902 $27,083 15.0% $48,228 $49,687 $51,341 $53,231 $55,412 17.5% 17,347 18,472 19,724 21,129 22,715 17.5% 45,676 46,801 48,053 49,458 51,044 20.0% 15,376 16,273 17,259 18,349 19,560 20.0% 43,705 44,602 45,588 46,678 47,889 22.5% 13,807 14,541 15,341 16,215 17,175 22.5% 42,136 42,871 43,670 44,544 45,504 25.0% 12,529 13,143 13,807 14,526 15,308 25.0% 40,858 41,472 42,136 42,855 43,637 Terminal Value at Perpetuity Growth Rate Total Value at Perpetuity Growth Rate Terminal Year Equity Discount Rate Terminal Year Equity Discount Rate Relevant Value Range $43,000 - $49,000 Discounted Value Amortization Depreciation Less: Taxes at 37.7% Less: Amortization Less: Depreciation Less: SG&A

Comparable Company Trading Analysis

34 Comparable Company Trading Analysis Summary Sum-of-the-Parts ____________________ (1) Based on fully-diluted MWP shares of 12.1 million. (2) Based on DCF value. (2) Current Equity Value: $606,163 Implied Merger/Redemption Consideration: $734,842 $400,000 $80,000 $43,000 $52,343 $575,343 $921,343 $675,000 $145,000 $49,000 $0 $100,000 $200,000 $300,000 $400,000 $500,000 $600,000 $700,000 $800,000 $900,000 $1,000,000 89.7% of MWE GP Interest MWE LP Units Frac Spread Business Net Cash Total MWP Implied Equity Value (dollars in thousands) Value Per MWP Share (1) $33.19 - $56.00 $6.64 - $12.03 $3.57 - $4.07 $4.34 $47.73 - $76.44

35 Comparable Company Trading Analysis Comparable GP Trading Statistics (dollars in millions, except per unit amounts) ____________________ (1) Equity value for GP only. Equity value for common and subordinated units calculated at prevailing yield on applicable date except for MWP, where MWE is calculated based on 30-day VWAP pursuant to the Transaction. (2) Pro forma for Atlas Pipeline Partners' acquisition of midstream assets from Anadarko Petroleum Corporation. (3) GP cash flows tax effected by a 35% tax rate. (4) Pro forma for acquisition of 39.0 MM Energy Transfer Equity units, TEPPCO's GP and 4.4 MM of TEPPCO common units; pro forma for 20.1 MM units issued in a private placement. In calculating GP Equity Value/EPD GP distribution, the value of EPD units owned and the value of the TEPPCO GP, TEPPCO LP units and Energy Transfer Equity LP units have been deducted. The value of the TEPPCO GP, TEPPCO LP units and Energy Transfer Equity LP units have an assumed blended average multiple of 20.0x. (5) Pro forma for 1.5 MM common unit offering. (6) Equity value excludes assumed $46.0 million value of the Frac Spread Business and $52.3 million of net cash. (2) A B C D E F G H I J K L M N O P Q R % of Distributions from MLP to GP Price 52 Week Common Equity Units in MLP General Partner Annual Distributions Annual GP Equity Value/ (08/31/2007) High Low High Units Value Common Sub Ownership % to GP Tier Common Sub GP Other Total Yield GP Dist. (1) Alliance Holdings GP, L.P. $25.20 $33.73 $18.41 74.7% 59.9 $1,508.5 15.54 0.00 2.0% 28.0% 50% $34.8 $0.0 $31.9 $0.0 $66.7 4.21% 31.0x Atlas Pipeline Holdings, L.P. (2) 40.69 47.12 20.55 86.4% 25.4 1,034.6 5.44 0.00 2.0% 21.6% 50% 18.9 0.0 19.9 0.0 38.9 2.56% 39.3 Buckeye GP Holdings, L.P. 31.40 39.89 15.22 78.7% 28.3 888.6 0.08 0.00 0.6% 19.9% 45% 0.3 0.0 33.3 0.0 33.6 3.18% 26.5 Crosstex Energy Inc. 32.84 38.52 27.13 85.3% 46.0 1,509.9 5.33 11.08 2.0% 28.9% 50% 12.2 25.3 40.3 0.0 77.7 2.80% 35.5 (3) Energy Transfer Equity L.P. 36.75 42.95 26.04 85.6% 222.8 8,188.9 62.50 0.00 2.0% 35.2% 50% 201.6 0.0 120.1 0.0 321.7 4.05% 41.1 Enterprise GP Holdings L.P. (4) 38.31 46.96 31.33 81.6% 139.2 5,332.8 13.45 0.00 2.0% 13.1% 25% 26.0 0.0 126.4 116.7 269.0 3.97% 20.6 Hiland Holdings GP, L.P. 30.23 42.22 18.75 71.6% 21.6 653.0 1.30 4.08 2.0% 13.8% 50% 3.8 12.0 4.3 0.0 20.1 2.91% 88.3 Inergy Holdings, L.P. (5) 44.98 56.09 32.80 80.2% 21.5 967.3 4.71 0.00 1.0% 22.6% 50% 11.0 0.0 34.0 0.0 45.0 4.54% 23.9 Magellan Midstream Holdings, L.P. 28.31 31.00 21.40 91.3% 62.6 1,773.5 0.00 0.00 2.0% 30.1% 50% 0.0 0.0 72.1 0.0 72.1 3.90% 24.6 Penn Virginia GP, L.P. 31.42 40.74 18.00 77.1% 39.1 1,227.7 19.59 0.00 2.0% 15.3% 50% 32.9 0.0 14.0 0.0 46.9 3.56% 48.6 Nustar GP Holdings, LLC 32.70 38.79 19.00 84.3% 42.5 1,389.8 10.23 0.00 2.0% 10.8% 25% 38.9 0.0 21.6 0.0 60.5 4.16% 34.8 Mean 1.8% 21.8% 45% $34.6 $3.4 $47.1 $10.6 $95.7 3.62% 37.7x Median 2.0% 21.6% 50% 18.9 0.0 33.3 0.0 60.5 3.90% 34.8 MWP $50.29 $64.47 $25.00 78.0% 12.1 $606.2 3.74 1.20 2.0% 26.2% 50% $7.9 $2.5 $24.6 $35.1 2.55% 21.7x (3)(6) MWP at MWE Offer $60.97 $64.47 $25.00 94.6% 12.1 $734.8 3.77 1.20 2.0% 26.2% 50% $8.0 $2.5 $24.6 $35.2 2.10% 29.5x (3)(6) 52-Week S

36 Comparable Company Trading Analysis 89.7% of MWE GP Interest (dollars in thousands) 2007 Q2 Annualized Distribution to 89.7% MWE GP Interest (After-Tax) $15,344 4.50% - 2.50% Value Range $340,976 - $613,757 2007 Q2 Annualized Distribution to 89.7% MWE GP Interest (After-Tax) $15,344 25.0x - 45.0x Value Range $383,598 - $690,476 Relevant Value Range $400,000 - $675,000 Relevant Cash Flow Multiple Relevant Yield Range

37 Comparable Company Trading Analysis Comparable MLP Trading Statistics(1) (dollars in millions, except per unit amounts) ____________________ (1) Estimates based on IBES consensus estimates. (2) Pro forma for $1.85 BB acquisition of Chaney Dell and Midkiff/Benedum natural gas gathering and processing systems from Anadarko (6-07). (3) Pro forma for $272.3 MM acquisition of midstream assets from DCP Midstream, LLC (7-07). (4) Pro forma for $420 MM acquisition of Escambia Asset Co., LLC, Redman Energy Holdings, and MacLondon Energy, LP. (7-07). (5) Pro forma for 11.5 MM common units offering with net proceeds of $312.5 MM used to pay down debt (7-07). (6) Pro forma for $78 MM acquisition of 20% interest in Discovery Producer Services LLC (6-07). A B C D E F G H I J K L M N O P Equity Value/ Enterprise Value/ 2008E 5-Year Price Equity Enterprise Net Income Cash Flow EBITDA Dist. Dist. EPU Total (08/31/2007) High Low Value Value 2007E 2008E 2007E 2008E 2007E 2008E Yield Yield Growth Return Atlas Pipeline Partners (2) $46.40 $56.88 $42.62 $1,830 $2,958 NM 18.7x 11.8x 9.9x 17.1x 9.0x 7.5% 8.3% 5.0% 12.5% Copano Energy, L.L.C. 38.99 45.03 25.60 1,712 2,015 25.7 22.0 14.7 15.5 15.9 13.7 4.5 6.6 12.0 16.5 Crosstex Energy 35.38 40.25 31.47 1,568 2,705 NM NM 17.4 13.3 14.9 11.2 6.4 7.0 7.5 13.9 DCP Midstream Partners (3) 45.25 51.33 27.30 991 1,430 24.2 23.1 16.3 14.5 16.2 10.2 4.7 5.4 8.5 13.2 Duncan Energy Partners LP 23.98 29.55 20.25 497 662 26.6 23.1 9.4 11.6 9.6 7.6 6.7 7.7 4.0 10.7 Eagle Rock Energy Partners (4) 21.93 27.64 17.50 1,596 2,242 NM 17.9 17.5 10.9 18.5 10.6 6.6 9.8 8.5 15.1 Hiland Partners 50.01 61.75 43.86 474 642 NM 21.2 13.1 10.1 NM 8.4 5.9 6.4 10.5 16.4 Regency Energy Partners (5) 32.00 35.08 21.88 1,945 2,338 NM 22.8 17.1 14.2 16.6 13.4 4.8 5.3 9.0 13.8 Targa Resource Partners 30.00 35.28 22.75 964 1,249 NM NM 16.3 13.2 13.4 9.9 4.5 5.8 11.6 16.1 Williams Partners (6) 44.59 52.00 34.40 1,791 2,598 20.9 20.0 13.8 14.1 12.8 9.1 4.7 6.8 11.2 15.9 Mean 24.3x 21.1x 14.7x 12.7x 15.0x 10.3x 5.6% 6.9% 8.8% 14.4% Median 24.9 21.6 15.5 13.2 15.9 10.1 5.3 6.7 8.8 14.5 MarkWest LP $31.88 $38.00 $22.75 $1,187 $1,684 22.3x 18.6x 11.2x 11.7x 9.9x 8.3x 6.6% 7.2% 5.1% 11.7% 52-Week

38 Comparable Company Trading Analysis MWE LP Units (dollars in thousands, except per unit amounts) ____________________ (1) Compares to IBES consensus EBITDA estimate of $169.8 million. (2) Compares to IBES consensus EBITDA estimate of $203.0 million. (3) Relevant value to MWP assumes a current tax liability upon sale of negative $8.90 and a tax rate of 37.7%. 2007 Q2 Annualized Distribution per MWE LP Unit $2.12 Relevant Yield Range 7.00% - 4.50% Value Range per MWE Unit $30.29 - $47.11 2008E Distribution per MWE LP Unit $2.27 Relevant Yield Range 8.00% - 5.50% Value Range per MWE Unit $28.35 - $41.24 2007E MWE EBITDA (1) $158,188 Relevant Multiple Range 13.0x - 17.0x Enterprise Value Range $2,056,439 $2,689,189 Less: Net Debt (6/30/07) (496,624) Equity Value Range $1,559,815 $2,192,565 Value Range per MWE Unit $42.73 - $60.07 2008E MWE EBITDA (2) $201,027 Relevant Multiple Rate 8.5x 12.0x Enterprise Value Range $1,708,731 $2,412,326 Less: Net Debt (6/30/07) (496,624) Equity Value Range $1,212,107 $1,915,702 Value Range per MWE Unit $33.21 - $52.49 Relevant MWE Unit Value Range $32.00 - $55.00 Relevant Value to MWP (3) $80,000 - $145,000

Comparable Acquisition Analysis

39 Comparable Acquisition Analysis Summary Sum-of-the-Parts ____________________ (1) Based on fully-diluted MWP shares of 12.1 million. (2) Based on DCF value. (2) Current Equity Value: $606,163 Implied Merger/Redemption Consideration: $734,842 $405,343 $60,000 $43,000 $250,000 $541,343 $52,343 $49,000 $120,000 $320,000 $0 $100,000 $200,000 $300,000 $400,000 $500,000 $600,000 $700,000 $800,000 89.7% of MWE GP Interest MWE LP Units Frac Spread Business Net Cash Total MWP Implied Equity Value (dollars in thousands) Value Per MWP Share (1) $20.74 - $26.55 $4.98 - $9.96 $3.57 - $4.07 $4.34 $33.63 - $44.91

40 Comparable Acquisition Analysis Comparable GP Acquisitions (dollars in millions, except per unit amounts) Controlling Interest A B C D E F G H Transaction Run Rate IDR Run Rate Value/ Transaction Transaction Common Cash Flow IDR % Cash Flow Run Rate IDR Date (Acquiror/Target) Value Unit Price Acquired Tier to GP Cash Flow 01/08/97 Kinder Morgan/Enron Liquids $9.7 $27.88 $0.4 15% 3% 22.2x 10/18/97 Kinder Morgan/Santa Fe Pacific 85.0 41.13 3.6 28% 6% 23.6 03/02/98 El Paso/Leviathan 265.0 29.44 12.9 50% 20% 20.6 04/05/99 Columbia/National Propane 17.9 6.81 0.0 0% NA 05/27/99 Management Group/Suburban Propane 6.0 19.38 0.9 2% 2% 6.8 03/31/00 Duke Energy Field Services/TEPPCO 225.0 20.38 10.7 50% 15% 21.1 05/08/02 Management Group/74.1% of Alliance Resource Partners 4.8 24.07 0.5 2% 2% 10.3 04/21/03 Madison Dearborn & Carlyle/Riverstone/Williams Energy Partners 100.0 39.00 5.4 25% 6% 18.4 11/07/03 Affiliates of Energy Transfer Company/Heritage Propane Partners 30.0 34.90 2.9 25% 6% 10.4 03/05/04 Carlyle/Riverstone/Glenmoor, Ltd. (Buckeye GP) 235.0 53.53 14.8 45% 26% 15.9 11/01/04 Valero L.P./Kaneb Services, LLC 233.4 50.76 11.0 30% 10% 21.3 02/24/05 EPCO, Inc./TEPPCO 1,100.0 41.89 67.7 50% 29% 16.3 06/12/06 Plains All American Pipeline, L.P./Pacific Energy Partners, L.P. 700.0 32.09 3.2 2% 3% 114.9 06/28/06 Suburban Propane Partners, L.P./Suburban Energy Services Group LLC 71.8 31.20 2.9 15% 4% 24.5 05/08/07 Enterprise GP Holdings LP/TEPPCO 1,100.0 41.89 48.3 25% 16% 18.6 06/19/07 GE Energy Financial Services/Regency Energy Partners LP 603.0 25.23 1.4 2% 2% 132.3 Median - Highest % GP IDR Tier 19.6x Median - Less than 50% GP IDR Tier 22.2 Non-Controlling Interest A B C D E F G H Transaction Run Rate IDR Run Rate Value/ Transaction Transaction Common Cash Flow IDR % Cash Flow Run Rate IDR Date (Acquiror/Target) Value Unit Price Acquired Tier to GP Cash Flow 07/08/01 Investor Group/54% of Plains All American $40.8 $23.79 $0.9 2% 2% 43.2x 08/16/02 TransCanada/17.5% of Northern Border GP 12.0 37.25 1.8 25% NA 6.9 10/03/03 Goldman Sachs & Co./9.9% of GulfTerra Energy Partners 88.0 40.17 6.8 50% 30% 12.9 12/15/03 Enterprise Products Co./50.0% of GulfTerra Energy Partners 425.0 40.39 37.8 50% 31% 11.2 09/16/04 ONEOK/82.5% of Northern Border G.P. 154.5 41.05 9.2 25% 7% 16.8 07/27/04 Vulcan Capital/44.0% of Plains All American 62.0 33.37 9.6 25% 7% 14.7 Median - Highest % GP IDR Tier 12.1x Median - Less than 50% GP IDR Tier 15.7 NA

41 Comparable Acquisition Analysis 89.7% of MWE GP Interest (dollars in thousands) 2007 Q2 Annualized Distribution to 89.7% GP Interest (After-Tax) $15,344 16.0x - 21.0x Value Range $245,503 - $322,222 Relevant Value Range $250,000 - $320,000 Relevant Cash Flow Multiple

42 Comparable Acquisition Analysis MWE LP Units (dollars in millions, except per unit amounts) MLP Transactions Date Transaction EBITDA Announced Acquiror/Seller Value Multiple 06/06 Plains All American Pipeline/Pacific Energy Partners $2,315.0 13.7x 07/05 Valero L.P./Kaneb Pipe Line Partners L.P. 2,275.0 12.6 09/04 Enterprise Products Partners, L.P./GulfTerra Energy Partners, L.P. 4,939.0 11.8 10/97 Kinder Morgan Energy Partners/Santa Fe Pacific Pipeline Partners 1,473.0 12.7 Mean 12.7x Median 12.7 Natural Gas Midstream Asset Transactions Date Transaction EBITDA Announced Acquiror/Seller Value Multiple 06/07 Atlas Pipeline Partners, LP/100% Chaney Dell and 73% Midkiff/Benedum (Anadarko) $1,850.0 14.2x 05/07 DCP Midstream/Momentum Energy Group 635.0 NA 11/06 Williams Partners, L.P./74.9% Interest in Four Corners LLC (Williams Companies, Inc.) 1,223.0 9.4 07/06 Enterprise Products Partners L.P./Natural gas gathering systems and related gathering and processing contracts (Cerrito Gathering Co. Ltd) 325.0 NA 07/06 Regency Energy Partners, LP/TexStar Field Services LP (HM Capital Partners LLC) 352.1 8.8 04/06 Williams Partners, L.P./25.1% Interest in Four Corners LLC (Williams Companies, Inc.) 360.0 9.4 12/05 Southern Union Company/Sid Richardson Energy Services Company 1,600.0 11.5 10/05 Eagle Rock Energy, Inc.(Portfolio company of Natural Gas Partners)/Texas Gas Gathering and Processing Assets (ONEOK, Inc.) 528.0 8.7 08/05 Targa Resources, Inc.(Warburg Pincus LLC)/Dynegy Midstream Services LP 2,350.0 7.7 06/05 Copano Energy, L.L.C./ScissorTail Energy, LLC 500.0 9.1 05/05 ONEOK Inc./Midcontinent and Gulf Coast NGL Business (Koch) 1,350.0 9.6 04/05 Atlas Pipeline Partners L.P./ETC Oklahoma Pipeline, Ltd. (Energy Transfer Partners) 190.0 9.5 01/05 Energy Transfer Partners, L.P./Houston Pipe Line Company (AEP Corp.) 825.0 11.8 04/04 Energy Transfer Partners, L.P./TXU Fuel Co. (TXU Corp.) 502.0 10.0 11/03 Heritage Propane Partners/Energy Transfer Company 1,102.0 8.8 12/01 Kinder Morgan Energy Partners/Tejas Gas (InterGen) 750.0 10.0 10/01 Enbridge Energy Partners/Koch East Texas 230.5 8.8 09/01 TEPPCO Partners LP/Jonah Gas Gathering (Alberta Energy Co.) 360.0 8.0 01/01 American Electric Power/Houston Pipe Line Company (Enron) 726.6 9.7 08/00 Duke Energy/Market Hub Partners (NiSource Inc.) 400.0 14.3 Mean 10.0x Median 9.5

43 Comparable Acquisition Analysis MWE LP Units (dollars in thousands, except per unit amounts) ____________________ (1) Compares to IBES consensus EBITDA estimate of $169.8 million. (2) Relevant value to MWP assumes a current tax liability upon sale of negative $8.90 and a tax rate of 37.7%. LTM EBITDA (6/30/07) $146,003 Relevant Multiple Range 9.5x - 13.5x Enterprise Value Range $1,387,033 $1,971,047 Less: Net Debt (6/30/07) (496,624) Equity Value Range $890,409 $1,474,423 Value Range per MWE Unit $24.39 - $40.40 2007E MWE EBITDA (1) $158,188 Relevant Multiple Range 9.0x - 13.0x Enterprise Value Range $1,423,688 $2,056,439 Less: Net Debt (6/30/07) (496,624) Equity Value Range $927,064 $1,559,815 Value Range per MWE Unit $25.40 - $42.73 Relevant MWE Unit Value Range $25.00 - $43.00 Relevant Value to MWP (2) $60,000 - $120,000

Cost of Equity

44 Cost of Equity GP Comparables Capital Asset Pricing Method ____________________ (1) Source: Ibbottson & Associates. (2) Thirty year government bond yield plus the historical spread between the long bond and the S&P 500. (3) Thirty year government bond yield less the historical spread between the long bond and the three month bill. (4) Source: Bloomberg ("2 Year 104 Point"). (5) Book value of net debt to market value of equity. (6) Unlevered beta equals (levered Beta/(1 + ((1 - tax rate) * debt/equity))). Three Month Treasury Bill (08/31/2007) 4.12% 4.116 Estimated Future Market Return (2) 10.04% Thirty Year Government Bond (08/31/2007) 4.84% 4.835 Estimated Future Risk Free Rate (3) 3.44% Historical Spread Between Long Bond & Bill (1) 1.40% Estimated Differential 6.60% Historical Spread Between Long Bond & S&P 500 (1) 5.20% Levered Assumed Net Debt Unlevered Levered Unlevered Company Beta (4) Tax Rate Equity (5) Beta (6) Return Return Alliance Holdings GP, L.P. AHGP 0.49 0.0% (0.0%) 0.49 6.7% 6.7% Atlas Pipeline Holdings, L.P. AHD 0.68 0.0% (0.0%) 0.68 7.9% 7.9% Buckeye GP Holdings, L.P. BGH 0.40 0.0% 1.8% 0.39 6.1% 6.0% Crosstex Energy Inc. XTXI 0.97 35.0% (0.5%) 0.97 9.8% 9.9% Energy Transfer Equity L.P. ETE 0.38 0.0% 19.1% 0.32 5.9% 5.5% Enterprise GP Holdings L.P. EPE 0.71 0.0% 34.0% 0.53 8.1% 6.9% Hiland Holdings GP, L.P. HPGP 0.28 0.0% 0.0% 0.28 5.3% 5.3% Inergy Holdings, L.P. NRGP 0.41 0.0% 3.2% 0.40 6.1% 6.1% Magellan Midstream Holdings, L.P. MGG 0.68 0.0% (0.7%) 0.68 7.9% 8.0% Penn Virginia GP, L.P. PVG 0.65 0.0% (0.8%) 0.66 7.7% 7.8% Nustar GP Holdings LLC VEH 1.07 0.0% (0.2%) 1.07 10.5% 10.5% Average 0.61 3.2% 5.1% 0.59 7.5% 7.3% Net Debt/ Equity Cost of Equity at Various Unlevered Beta and Capital Structures Cap Structure 0.500 0.550 0.600 0.650 0.700 (20.0%) 6.1% 6.3% 6.6% 6.9% 7.1% (10.0%) 6.4% 6.7% 7.0% 7.3% 7.6% 0.0% 6.7% 7.1% 7.4% 7.7% 8.1% 10.0% 7.1% 7.4% 7.8% 8.2% 8.5% 20.0% 7.4% 7.8% 8.2% 8.6% 9.0% 30.0% 7.7% 8.2% 8.6% 9.0% 9.4%

45 Cost of Equity MLP Comparables Capital Asset Pricing Method ____________________ (1) Source: Ibbottson & Associates. (2) Thirty year government bond yield plus the historical spread between the long bond and the S&P 500. (3) Thirty year government bond yield less the historical spread between the long bond and the three month bill. (4) Source: Bloomberg ("2 Year 104 Point"). (5) Book value of net debt to market value of equity. (6) Unlevered beta equals (levered Beta/(1 + ((1 - tax rate) * debt/equity))). Three Month Treasury Bill (08/31/2007) 4.12% Estimated Future Market Return (2) 10.04% Thirty Year Government Bond (08/31/2007) 4.84% Estimated Future Risk Free Rate (3) 3.44% Historical Spread Between Long Bond & Bill (1) 1.40% Estimated Differential 6.60% Historical Spread Between Long Bond & S&P 500 (1) 5.20% Levered Assumed Net Debt Unlevered Levered Unlevered Company Beta (4) Tax Rate Equity (5) Beta (6) Return Return Atlas Pipeline Partners 0.58 0.0% 59.5% 0.36 7.3% 5.8% Copano Energy, L.L.C. 0.61 0.0% 15.0% 0.53 7.5% 6.9% Crosstex Energy 0.74 0.0% 72.3% 0.43 8.3% 6.3% DCP Midstream Partners 0.57 0.0% 38.8% 0.41 7.2% 6.1% Duncan Energy Partners LP 0.77 0.0% 32.4% 0.58 8.5% 7.3% Eagle Rock Energy Partners 0.61 0.0% 40.3% 0.43 7.5% 6.3% Hiland Partners LC 0.59 0.0% 33.3% 0.44 7.3% 6.4% Regency Energy Partners 0.44 0.0% 18.6% 0.37 6.3% 5.9% Targa Resource Partners 0.45 0.0% 28.6% 0.35 6.4% 5.7% Williams Partners 0.83 0.0% 43.9% 0.58 8.9% 7.2% Average 0.62 0.0% 38.3% 0.45 7.5% 6.4% Net Debt/ Equity Cost of Equity at Various Unlevered Beta and Capital Structures Cap Structure 0.400 0.425 0.450 0.475 0.500 20.0% 6.6% 6.8% 7.0% 7.2% 7.4% 30.0% 6.9% 7.1% 7.3% 7.5% 7.7% 40.0% 7.1% 7.4% 7.6% 7.8% 8.1% 50.0% 7.4% 7.6% 7.9% 8.1% 8.4% 60.0% 7.7% 7.9% 8.2% 8.5% 8.7% 70.0% 7.9% 8.2% 8.5% 8.8% 9.0%

Pro Forma Analysis

46 Pro Forma Analysis Key Assumptions Merrill Lynch has analyzed the pro forma impact of the acquisition of MWP by MWE for $20.00 in cash and 1.285 MWE units, or approximately $735 million of total Merger/Redemption Consideration as of August 31, 2007. Two pro forma cases have been assumed: Base Case assuming no incremental annual acquisitions by MWE Additional Acquisition Case assuming incremental annual acquisitions of $200 million throughout the forecast period beyond MWE stand alone projections based on MWE and MWP management guidance Consummated at 10.0x current year EBITDA (as compared to 8.0x on a stand alone basis) All other financing and operating assumptions identical to Base Case SG&A savings of $2.5 million per year from removal of MWP as a publicly traded entity 8.5% interest rate on acquisition debt Pro forma distribution coverage equal to 1.15x as provided by MWE management and adjusted as necessary to maintain a slightly increasing distribution per unit IDRs valued (for tax calculation purposes) as total purchase price less value of MWE LP units owned, cash and the estimated value of the Frac Spread Business

47 Pro Forma Analysis Key Assumptions (cont’d) MWP is assumed to become a wholly-owned subsidiary of MWE, and approximately 21.9 million Class A Units at a value of $29.01 (as provided by MWE management assuming a 6.25% yield and the expected 2007E distribution per Class A Unit) are assumed to be exchanged for the approximately $470 million net value of the MWE GP interest and the approximately $167 million MWE LP interest held by MWP The Class A Units are a new class of units representing limited partnership interests in MWE. Pursuant to the Transaction, the Class A Units to be owned within the MWP subsidiary of MWE will receive lower distributions per unit than other MWE LP units as they will not participate in the cash flow of the MWP subsidiary The MWP subsidiary is projected to undertake $225 million of leverage at an assumed interest rate of 8.50% in connection with the Redemption Merrill Lynch has assumed that the current and former management of MWP/MWE that currently own the other 10.3% MWE GP interest will sell such interest to MWE for approximately $51.0 million consisting of cash consideration of approximately $16.7 million and 1.1 million MWE units valued at the August 31, 2007 price of $31.88 per MWE unit for the analysis herein (Note: Merrill Lynch understands MWE is still negotiating acquisition of 1.6% of Class B Membership Interests) Tax depreciation at MWE and the MWP subsidiary as provided by MWE management

48 Overview ($60.97 Per MWP Share Purchase Price) General (dollars in thousands, except per unit amounts) Implied 89.7% GP Interest Value (dollars in thousands) Pro Forma Analysis Class A Unit Issuance (dollars in thousands, except per unit amounts) ____________________ (1) Based on 30 day MWE volume weighted average price of $33.58. MWP Subsidiary Income/Dividend to MWE (dollars in thousands) Assumptions Transaction Effective Date 01/01/08 MWE Unit Price (As of 08/31/07) $31.88 Value of Frac Spread Business $46,000 Transaction Overview MWP Purchase Price $60.97 Shares Outstanding 12,053 Implied Value $734,842 Purchase Price $734,842 Less: Value of MWE Units Owned (1)(2) (166,872) Less: Net Cash (12/31/07) (52,343) Less: Value of Frac Spread Business (46,000) Net Purchase Price $469,628 Class A Units Issued in Exchange for 89.7% GP Interest and MWE LP Units Owned by MWP: Net GP Purchase Price $469,628 Plus: Value of MWE Units Owned (1) 166,872 $636,500 $29.01 Class A Common Units Issued 21,941 Years Ending December 31, 2008E 2009E 2010E 2011E 2012E Class A Units Issued and Outstanding 21,941 21,941 21,941 21,941 21,941 Class A Units Distribution per Unit $1.92 $2.13 $2.15 $2.24 $2.34 $42,146 $46,798 $47,223 $49,123 $51,446 Debt at MWP Subsidiary $225,000 $225,000 $225,000 $225,000 $225,000 8.50% 8.50% 8.50% 8.50% 8.50% Annual MWP Subsidiary Interest Expense $19,125 $19,125 $19,125 $19,125 $19,125 Frac Spread Operating Income $13,352 $6,067 $6,902 $6,759 $8,511 Plus: Taxable Income Allocation from MWP Before Depreciation 56,056 61,633 61,067 64,271 67,512 Less: Tax Depreciation Allocation from MWE (15,982) (17,746) (17,949) (16,960) (16,528) Less: Interest Expense (19,125) (19,125) (19,125) (19,125) (19,125) Taxable Income 34,301 30,830 30,896 34,944 40,371 Income Tax Rate 37.7% 37.7% 37.7% 37.7% 37.7% Income Tax $12,931 $11,623 $11,648 $13,174 $15,220 Frac Spread Operating Income $13,352 $6,067 $6,902 $6,759 $8,511 Plus: Class A Common Unit Distribution 42,146 46,798 47,223 49,123 51,446 Less: Interest Expense (19,125) (19,125) (19,125) (19,125) (19,125) Less: Income Taxes (12,931) (11,623) (11,648) (13,174) (15,220) Cash Dividend Payment to MWE $23,442 $22,117 $23,352 $23,583 $25,612 Interest Rate on MWP Subsidiary's Debt Annual Class A Unit Distributions Issuance Price Provided by MWE Management Total Value Exchanged for Class A Common Units

49 Pro Forma Analysis Sources & Uses(1) (dollars and units in thousands) Overview ($60.97 Per MWP Share Purchase Price) (cont'd) ____________________ (1) Note: Merrill Lynch understands MWE is still negotiating acquisition of 1.6% of Class B Membership Interests. Sources and Uses of Funds Equity Issuance Overview Use of Funds: Amount Source of Funds: Amount Unit Consideration for MWP Shareholders $493,775 MWE Units $528,041 Cash Consideration for MWP Shareholders 241,067 MWP Available Cash on Hand 22,667 Unit Consideration for Buyout of Class B Membership Interest 34,266 MWE Available Cash on Hand 23,329 Cash Consideration for Buyout of Class B Membership Interest 16,729 New MWP Debt 225,000 Transaction Fees 13,200 Total $799,037 Total $799,037 Equity Issuance Overview % of Consideration in Units 67.2% % of Consideration in Cash 32.8% Purchase of MWP Interest Funded by Units $493,775 MWE Current Unit Price $31.88 New Units Issued 15,489 Purchase of Management Interest Funded by Units $34,266 MWE Current Unit Price $31.88 New Units Issued 1,075 Total Purchase Funded by Units $528,041 MWE Current Unit Price $31.88 Total New Units Issued 16,563 Total Purchase Funded by both MWP and MWE Cash on Hand and Debt Raised $270,996 Unit Consideration for Buyout of Class B Membership Interest $34,266 Cash Consideration for Buyout of Class B Membership Interest 16,729 Total Value of Class B Management Interest Buyout $50,995

50 Pro Forma Analysis Pro Forma Ownership (dollars and units in thousands) Overview ($60.97 Per MWP Share Purchase Price) (cont'd) MWE Units Issued and Exchanged in Transaction Transaction Adjustments Resulting Exchange MWE Units MWP Ownership Holder Shares % Ownership Ratio Issued John Fox 5,382,537 44.7% 1.285 6,916,560 Other MWP Shareholders 6,670,819 55.3% 1.285 8,572,002 Total Diluted Shares 12,053,356 Units Issued for Management GP Interest 1,074,836 Units Exchanged for 89.7% Net GP Interest 21,940,705 Total Units Issued and Exchanged 38,504,103 Current MWE Ownership MWE Holder LP Units % Ownership John Fox 180,924 0.5% MWE Management 342,566 0.9% MWP 4,938,992 13.5% Public 31,037,427 85.0% Total Units 36,499,909 Pro Forma MWE Ownership MWE Pro Forma Holder LP Units % Ownership John Fox 7,097,484 10.1% Management 1,417,402 2.0% Current Public MWE Unitholders 31,037,427 44.3% Current Other MWP Shareholders 8,572,002 12.2% MWP Subsidiary of MWE 21,940,705 31.3% Total Units 70,065,020

51 Pro Forma Analysis Base Case (dollars in thousands, except per unit amounts) Pro Forma Projections ($60.97 per MWP Share Purchase Price) On a stand alone basis and based on the MWE projections contained herein, MWE would have paid aggregate distributions to its general partner of $237.0 million over the 2008E to 2012E forecast period. ____________________ (1) Equals frac spread operating income plus distributions on MWE LP units owned by MWP less interest expense and income taxes. (2) EBITDA includes other non-cash items. Years Ending December 31, '08E - '12E 2008E 2009E 2010E 2011E 2012E CAGR MWE EBITDA $201,027 $234,483 $243,581 $264,653 $284,252 9.0% Plus: Other Non-Cash Items 17,116 15,295 15,295 15,295 15,295 Less: Interest Expense (55,875) (61,725) (68,207) (72,383) (76,364) Less: Tax Depreciation (123,827) (129,257) (134,964) (139,050) (145,024) Taxable Income Before MWP Dividend Payment 38,441 58,796 55,705 68,515 78,158 MWP Dividend (1) 23,442 22,117 23,352 23,583 25,612 MWE Taxable Income 61,883 80,913 79,057 92,098 103,770 Plus: Depreciation 123,827 129,257 134,964 139,050 145,024 Plus: Non-Cash Interest Expense 2,912 2,912 2,912 2,912 2,912 Less: Maintenance Capital Expenditures (4,566) (7,431) (6,541) (7,291) (8,041) Base Distributable Cash Flow 184,056 205,652 210,393 226,769 243,666 Less: MWP Dividend (1) (23,442) (22,117) (23,352) (23,583) (25,612) Pro Forma Distributable Cash Flow Available to Units Owned by MWP Subsidiary $160,615 $183,535 $187,041 $203,186 $218,054 7.9% Assumed Pro Forma Distribution Coverage 1.15x 1.15x 1.13x 1.15x 1.15x Cash Flow Available for Distribution to LP Units Owned by MWP Subsidiary 139,667 159,597 165,523 176,684 189,612 Pro Forma Total Weighted Average LP Units Outstanding 72,708 74,826 76,905 78,915 80,866 Pro Forma Distribution per LP Unit Owned by MWP Subsidiary $1.92 $2.13 $2.15 $2.24 $2.34 LP Units Owned by MWP Sub 21,941 21,941 21,941 21,941 21,941 Cash Flow Distributed to LP Units Owned by MWP Subsidiary $42,146 $46,798 $47,223 $49,123 $51,446 Base Distributable Cash Flow $184,056 $205,652 $210,393 $226,769 $243,666 Assumed Pro Forma Distribution Coverage 1.15x 1.15x 1.13x 1.15x 1.15x Total Cash Flow Distributed $160,051 $178,830 $186,189 $197,190 $211,883 Less: Cash Flow Distributed to LP Units Owned by MWP Subsidiary (42,146) (46,798) (47,223) (49,123) (51,446) Cash Flow Available for Distribution to LP Units Not Owned by MWP Subsidiary $117,905 $132,032 $138,965 $148,067 $160,438 Pro Forma Weighted Average LP Units Outstanding (Excluding LP Units Owned by MWP Subsidiary) 50,739 52,873 54,950 56,965 58,911 Pro Forma Distribution per Unit to LP Units Not Owned by MWP Subsidiary $2.32 $2.50 $2.53 $2.60 $2.72 4.0% Stand Alone Distribution per LP Unit (Accretion/Dilution) 2.4% 5.3% 5.3% 6.2% 9.6% Implied Unit Price @ 6.50% Yield $35.75 $38.42 $38.91 $39.99 $41.90 Implied Unit Price at 5.50% Yield $42.25 $45.40 $45.98 $47.26 $49.52 4.0% Implied Stand Alone Unit Price Accretion/(Dilution) @ 5.50% Yield 21.1% 24.4% 24.4% 25.6% 29.5% Base Pro Forma Distributable Cash Flow per Unit Not Owned by MWP Subsidiary $2.67 $2.87 $2.86 $2.99 $3.13 4.0% Stand Alone Distributable Cash Flow per Unit Accretion/(Dilution) 2.1% 4.5% 7.8% 10.9% 15.0% Total Debt $977,374 $1,073,220 $1,127,835 $1,177,929 $1,221,005 Total Debt/EBITDA (2) 4.2x 4.2x 4.2x 4.1x 4.0x EBITDA (2) /Interest 4.1 4.1 3.9 4.0 4.0 Base Case

52 Pro Forma Analysis Additional Acquisition Case (dollars in thousands, except per unit amounts) Pro Forma Projections ($60.97 per MWP Share Purchase Price) (cont'd) On a stand alone basis and based on the MWE projections contained herein, MWE would have paid aggregate distributions to its general partner of $302.6 million over the 2008E to 2012E forecast period. ____________________ (1) Equals frac spread operating income plus distributions on MWE LP units owned by MWP less interest expense and income taxes. (2) EBITDA includes other non-cash items. Years Ending December 31, '08E - '12E 2008E 2009E 2010E 2011E 2012E CAGR MWE EBITDA $201,027 $234,483 $243,581 $264,653 $284,252 9.0% Plus: Other Non-Cash Items 17,116 15,295 15,295 15,295 15,295 Less: Interest Expense (55,875) (61,725) (68,207) (72,383) (76,364) Less: Tax Depreciation (135,059) (162,973) (191,165) (217,722) (234,948) Taxable Income Before MWP Dividend Payment 27,209 25,080 (495) (10,157) (11,766) MWP Dividend (1) 25,742 28,471 33,576 37,203 41,297 MWE Taxable Income 52,951 53,551 33,081 27,046 29,531 Plus: Depreciation 135,059 162,973 191,165 217,722 234,948 Plus: Non-Cash Interest Expense 2,912 2,912 2,912 2,912 2,912 Less: Maintenance Capital Expenditures (4,566) (7,431) (6,541) (7,291) (8,041) Base Distributable Cash Flow 186,357 212,006 220,616 240,390 259,351 Plus: Additional EBITDA from Incremental Acquisitions 10,000 30,000 50,000 70,000 90,000 Less: Additional Interest Expense from Incremental Acquisitions (3,300) (9,900) (16,500) (23,100) (29,700) Less: Additional Maintenance Capex from Incremental Acquisitions (400) (1,200) (2,000) (2,800) (3,600) Plus: Incremental Distributable Cash Flow 6,300 18,900 31,500 44,100 56,700 Less: MWP Dividend (1) (25,742) (28,471) (33,576) (37,203) (41,297) Pro Forma Distributable Cash Flow Available to Units Owned by MWP Subsidiary $166,915 $202,435 $218,541 $247,286 $274,754 13.3% Assumed Pro Forma Distribution Coverage 1.15x 1.15x 1.13x 1.15x 1.15x Cash Flow Available for Distribution to LP Units Owned by MWP Subsidiary 145,145 176,032 193,399 215,031 238,916 Pro Forma Total Weighted Average LP Units Outstanding 74,237 78,854 83,227 87,342 91,271 Pro Forma Distribution per LP Unit Owned by MWP Subsidiary $1.96 $2.23 $2.32 $2.46 $2.62 LP Units Owned by MWP Sub 21,941 21,941 21,941 21,941 21,941 Cash Flow Distributed to LP Units Owned by MWP Subsidiary $42,898 $48,980 $50,985 $54,017 $57,433 Base Distributable Cash Flow $192,657 $230,906 $252,116 $284,490 $316,051 Assumed Pro Forma Distribution Coverage 1.15x 1.15x 1.13x 1.15x 1.15x Total Cash Flow Distributed $167,529 $200,790 $223,112 $247,382 $274,827 Less: Cash Flow Distributed to LP Units Owned by MWP Subsidiary (42,898) (48,980) (50,985) (54,017) (57,433) Cash Flow Available for Distribution to LP Units Not Owned by MWP Subsidiary $124,632 $151,810 $172,127 $193,365 $217,394 Pro Forma Weighted Average LP Units Outstanding (Excluding LP Units Owned by MWP Subsidiary) 52,230 56,884 61,255 65,379 69,301 Pro Forma Distribution per Unit to LP Units Not Owned by MWP Subsidiary $2.39 $2.67 $2.81 $2.96 $3.14 7.1% Stand Alone Distribution per LP Unit (Accretion/Dilution) 5.2% 12.5% 17.0% 20.9% 26.2% Implied Unit Price @ 6.50% Yield $36.71 $41.06 $43.23 $45.50 $48.26 Implied Unit Price at 5.50% Yield $43.39 $48.52 $51.09 $53.77 $57.04 7.1% Implied Stand Alone Unit Price Accretion/(Dilution) @ 5.50% Yield 24.3% 33.0% 38.2% 42.9% 49.2% Base Pro Forma Distributable Cash Flow per Unit Not Owned by MWP Subsidiary $2.74 $3.07 $3.17 $3.40 $3.61 7.1% Stand Alone Distributable Cash Flow per Unit Accretion/(Dilution) 4.8% 11.7% 19.8% 26.2% 32.4% Total Debt $1,057,374 $1,233,220 $1,367,835 $1,497,929 $1,621,005 Total Debt/EBITDA (2) 4.4x 4.3x 4.3x 4.2x 4.1x EBITDA (2) /Interest 4.3 4.6 4.6 4.9 5.2 Additional Acquisition Case

53 Pro Forma Analysis Distributable Cash Flow Per MWE LP Unit Stand Alone $60.97 Per MWP Share Purchase Price (Additional Acquisition Case) $60.97 Per MWP Share Purchase Price 2008E 2009E $0 $2.67 / 2.1% $2.87 / 4.5% 200 2.74 / 4.8% 3.07 / 11.7% 400 2.79 / 6.5% 3.20 / 16.3% 600 2.83 / 8.3% 3.32 / 20.9% 800 2.88 / 10.0% 3.44 / 25.3% 1,000 2.93 / 11.7% 3.56 / 29.6% Additional Acquisition Case Distributable Cash Flow Per LP Unit / Accretion/(Dilution) $60.97 Purchase Price per MWP Share Incremental Acquisitions ($MM) $2.62 $2.75 $2.65 $2.69 $2.72 $2.67 $2.87 $2.86 $2.99 $3.13 $2.74 $3.07 $3.17 $3.40 $3.61 $0.00 $0.50 $1.00 $1.50 $2.00 $2.50 $3.00 $3.50 $4.00 2008E 2009E 2010E 2011E 2012E (Distributable Cash Flow per LP Unit)

54 Pro Forma Analysis Implied MWE Unit Price ____________________ (1) Assumes a 6.5% yield. (2) Assumes a 5.5% yield. $60.97 Per MWP Share Purchase Price (Base Case @ 6.50% Yield) Stand Alone(1) $60.97 Per MWP Share Purchase Price (Additional Acquisition Case)(2) $60.97 Per MWP Share Purchase Price (Base Case @ 5.50% Yield) 2008E $0 $42.25 / 21.1% $45.40 / 24.4% 200 43.39 / 24.3% 48.52 / 33.0% 400 44.12 / 26.4% 50.55 / 38.5% 600 44.84 / 28.5% 52.52 / 43.9% 800 45.57 / 30.6% 54.45 / 49.2% 1,000 46.29 / 32.6% 56.34 / 54.4% Implied MWP Unit Price / Accretion/(Dilution) Incremental Acquisitions ($MM) 2009E $60.97 Purchase Price per MWP Share Additional Acquisition Case $34.90 $36.49 $36.96 $37.64 $38.24 $35.75 $38.42 $38.91 $39.99 $41.90 $45.40 $45.98 $47.26 $49.52 $43.39 $48.52 $51.09 $53.77 $57.04 $42.25 $0.00 $10.00 $20.00 $30.00 $40.00 $50.00 $60.00 2008E 2009E 2010E 2011E 2012E (Implied Unit Price)

55 Disclaimers Merrill Lynch prohibits (a) employees from, directly or indirectly, offering a favorable research rating or specific price target, or offering to change such rating or price target, as consideration or inducement for the receipt of business or for compensation, and (b) Research Analysts from being compensated for involvement in investment banking transactions except to the extent that such participation is intended to benefit investor clients. This proposal is confidential, for your private use only, and may not be shared with others (other than your advisors) without Merrill Lynch's written permission, except that you (and each of your employees, representatives or other agents) may disclose to any and all persons, without limitation of any kind, the tax treatment and tax structure of the proposal and all materials of any kind (including opinions or other tax analyses) that are provided to you relating to such tax treatment and tax structure. For purposes of the preceding sentence, tax refers to U.S. federal and state tax. This proposal is for discussion purposes only. Merrill Lynch is not an expert on, and does not render opinions regarding, legal, accounting, regulatory or tax matters. You should consult with your advisors concerning these matters before undertaking the proposed transaction.