8-K

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM 8-K

CURRENT REPORT
PURSUANT TO SECTION 13 OR 15(d) OF
THE SECURITIES EXCHANGE ACT OF 1934

Date of Report (Date of earliest event reported): September 6, 2006

MARKWEST HYDROCARBON, INC.(Exact name of registrant as specified in its charter)

Delaware	001-14841	84-1352233
(State or other jurisdiction of incorporation or organization)	(Commission File Number)	(I.R.S. Employer Identification Number)

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

(Address of principal executive offices)

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

Former Address
Not applicable.

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

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

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

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

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

Item 1.01 Entry into a Material Definitive Contract

In connection with the retirement of James G. Ivey, Chief Financial Officer, from MarkWest Hydrocarbon, Inc. (“Registrant”) (as described in Item 5.02 below), Registrant entered into a Consulting Services Agreement and a Separation Agreement with Mr. Ivey.  The Consulting Services Agreement was entered into September 6, 2006, and will become effective October 2, 2006, and the Separation Agreement was also entered into September 6, 2006, and will become effective at the end of a seven-day revocation period provided by applicable law.  Pursuant to the Consulting Services Agreement, Mr. Ivey will provide consulting services to the Registrant from October 2 through October 31, 2006, and will receive compensation in the amount of $19,850 for the full term of the Consulting Services Agreement.  Pursuant to the Separation Agreement and based on the Company’s 1997 Severance Plan for Executive Officers, the Registrant will provide Mr. Ivey with the following: bi-weekly payments for a period of eighteen (18) months (i.e. through March 2008) on an annual rate of $221,800; reimbursement of Mr. Ivey’s insurance premiums necessary to continue his health insurance coverage under the Registrant’s insurance plan for a period of up to eighteen (18) months; subject to Board determination and approval, prorated incentive compensation, if any, payable in 2007; and any earned but unused vacation, and availability of vested 401K account funds.  Also pursuant to the Separation Agreement, Mr. Ivey executed a release and waiver of claims against the Registrant and provided non-compete and non-solicitation covenants for the 18 month period of separation payments referenced above.

Item 5.02  Departure of Directors or Principal Officers; Election of Directors; Appointment of Principal Officers

On September 6, 2006, the Registrant issued a press release announcing the upcoming retirement of James G. Ivey, Chief Financial Officer.  Mr. Ivey will continue as CFO until October 1, 2006, the date set for his retirement.  A copy of the press release is attached hereto as Exhibit 99.1.

The Registrant also announced that Nancy K. Masten has been named as the acting Chief Financial Officer, effective October 1, 2006.  Ms. Masten, 36, is currently the Chief Accounting Officer and Senior Vice President of MarkWest Hydrocarbon, Inc., having been in that position since November 2005.  Prior to joining MarkWest, Ms. Masten served as Chief Financial Officer of Experimental and Applied Sciences, Inc. (EAS) in Golden, Colorado (EAS is a wholly-owned subsidiary of the Ross Products Division of Abbott Laboratories).  Prior to her employment at EAS, Ms. Masten served as a Vice President at TransMontaigne, Inc. in Denver, Colorado.  Preceding that appointment, Ms. Masten was a Partner with Ernst & Young having spent twelve years with the firm at its Denver, London, New York and Washington, D.C. offices.  Ms. Masten earned a B.S. in Accounting from the University of Kansas and is a licensed CPA in the State of Colorado.

ITEM 9.01 FINANCIAL STATEMENTS AND EXHIBITS

(d) Exhibits

Exhibit No.	Description
99.1	Press Release Dated September 6, 2006

2

SIGNATURE

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

	MARKWEST HYDROCARBON, INC.
	(Registrant)
Date: September 6, 2006	By:	/s/ FRANK M. SEMPLE
		Frank M. Semple President and Chief Executive Officer

3

EX-99.1

Exhibit 99.1

MarkWest Hydrocarbon, Inc.	Contact:	Frank Semple, President & CEO
1515 Arapahoe Street		Jim Ivey, CFO
Tower 2, Suite 700		Andy Schroeder, VP and Treasurer
Denver, CO 80202	Phone:	(866) 858-0482 Fax (303) 290-8769
	E-mail:	investorrelations@markwest.com
	Website:	www.markwest.com

MARKWEST HYDROCARBON ANNOUNCES RETIREMENT
OF JIM IVEY AS CHIEF FINANCIAL OFFICER AND
APPOINTMENT OF NANCY K. MASTEN AS ACTING CHIEF FINANCIAL OFFICER

DENVER — September 6, 2006 — MarkWest Hydrocarbon, Inc. (AMEX: MWP) today announced the upcoming retirement of Jim Ivey, Chief Financial Officer.  Mr. Ivey will continue as CFO until October 1, 2006, the date set for his retirement.  He cited the desire to pursue other family and personal interests in reaching his decision to retire.  “Jim has been instrumental in developing MarkWest’s financial strategy and executing our business plan,” said Frank Semple, President and CEO.  “Jim’s experience will be missed; however, I am pleased to also announce that Nancy K. Masten has been named as the acting Chief Financial Officer while the Board of Directors considers all options for filling this very critical position.  Nancy is our current Chief Accounting Officer and her previous experience as the CFO for EAS, Inc. (a subsidiary of the Ross Products Division of Abbott Laboratories), Vice President for Transmontaigne, Inc. and as a Partner with Ernst & Young LLP will allow her to provide excellent leadership as the acting Chief Financial Officer.”

###

MarkWest Hydrocarbon, Inc. (AMEX: MWP) controls and operates MarkWest Energy Partners, L.P. (AMEX: MWE), a publicly-traded limited partnership engaged in the gathering, processing and transmission of natural gas; the transportation, fractionation and storage of natural gas liquids; and the gathering and transportation of crude oil. We also market natural gas and NGLs.

This press release includes “forward-looking statements” within the meaning of Section 27A of the Securities Act of 1933, as amended, and Section 21E of the Securities Exchange Act of 1934, as amended. All statements other than statements of historical facts included or incorporated herein may constitute forward-looking statements. Although we believe that the expectations reflected in the forward-looking statements are reasonable, we can give no assurance that such expectations will prove to be correct. The forward-looking statements involve risks and uncertainties that affect our operations, financial performance and other factors as discussed in our filings with the Securities and Exchange Commission (“SEC”). Among the factors that could cause results to differ materially are those risks discussed in our Form 10-K for the year ended December 31, 2005, and our Forms 10-Q for 2006, as filed with the SEC.