8-K

UNITED STATES
SECURITIES AND EXCHANGE COMMISSION

Washington, DC 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, 2005

MarkWest Hydrocarbon, Inc.

(Exact name of registrant as specified in its chapter)

Delaware	1-14841	84-1352233
(State or other jurisdiction of incorporation or organization)	(Commission File Number)	(IRS Employer Identification No.)
155 Inverness Drive West, Suite 200, Englewood, CO		80112-5000
(Address of principal executive offices)		(Zip code)
Registrant’s telephone number, including area code: 303-290-8700
Not Applicable
(Former name or former address, if changed since last report)

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

¨ Written communications pursuant to Rule 425 under the Securities Act (17 CFR 230.425)

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

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

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

ITEM 3.01  NOTICE OF DELISTING OR FAILURE TO SATISFY A CONTINUED LISTING RULE OR STANDARD; TRANSFER OF LISTING.

On September 6, 2005, MarkWest Hydrocarbon Inc. (the “Company”) received a letter from the American Stock Exchange (“AMEX”) advising that AMEX had accepted the Company’s updated Plan of Action to bring it back into compliance with the Exchange’s listing requirements by October 15, 2005.  The Company is currently not in compliance with the AMEX requirements as set forth in Sections 134, 1101 and 1003(d) of the Amex Company Guide for failure to file with the Securities and Exchange Commission (the “SEC”) its Annual Report on Form 10-K for year ended December 31, 2004 and its Quarterly Reports on Form 10-Q for the three months ended March 31, 2005 and June 30, 2005 by the prescribed filing deadline.

The Company is devoting substantial resources and working with its outside auditors to complete and file the Annual Report on Form 10-K and Quarterly Reports on Form 10-Q as soon as reasonably possible and to restore its compliance with the AMEX requirements.

Additionally, the Company announced that it has received an extension of the waiver of the covenant contained in its Credit Agreement requiring that the Company deliver its audited financial statements to the Lenders by March 31, 2005.  The Company had previously been granted a waiver of the covenant through August 31, 2005.  The previously granted waiver has now been extended to September 30, 2005.

Item 9.01.  FINANCIAL STATEMENTS AND EXHIBITS.

(c) Exhibits

The exhibit identified below is filed as part of this report:

Exhibit 99.1        Press Release of the American Stock Exchange Warning Letter.

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SIGNATURES

Pursuant to the requirements of the Securities Exchange Act of 1934, MarkWest Hydrocarbon, Inc., as registrant, has duly caused this report to be signed on its behalf by the undersigned, hereunto authorized.

	MarkWest Hydrocarbon, Inc.
	(Registrant)
Date: September 12, 2005	By:	/s/ Frank M. Semple
	Name:   Frank M. Semple
	Title:   Chief Executive Officer

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Exhibit Index

99.1                Press Release of the American Stock Exchange Warning Letter.

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EX-99.1

Exhibit 99.1

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

MARKWEST HYDROCARBON RECEIVES LETTER FROM AMEX EXTENDING
PLAN OF ACTION; EXTENSION OF WAIVERS FOR BANK CREDIT FACILITY

DENVER—September 8, 2005—MarkWest Hydrocarbon, Inc. (AMEX: MWP) (the “Company”), today announced that it received a letter from the American Stock Exchange (“AMEX”), advising that AMEX had accepted the Company’s updated Plan of Action to bring it back into compliance with the Exchange’s listing requirements by October 15, 2005.  The Company is currently not in compliance with the continued listing standards of the Exchange as a result of the Company’s failure to timely file certain Form 10-Ks and Form 10-Qs (the “SEC Filings”) with the Securities Exchange Commission (“SEC”), but under this accepted Plan of Action, listing is being continued pursuant to an extension of the previous AMEX filing compliance date.  

The updated Plan of Action establishes a schedule for the Company to complete and file its Annual Report on Form 10-K for year ended December 31, 2004, and its restated financial statements, Forms 10-Q/A for the first three quarters of 2004, and its Quarterly Reports on Form 10-Q for the first and second quarters of 2005.

Additionally, the Company today announced that it has received an extension of the waiver of the covenant contained in its Credit Agreement requiring that the Company deliver its audited financial statements to the Lenders by March 31, 2005.  The Company had previously been granted a waiver of the covenant through August 31, 2005.  The previously granted waiver has now been extended to September 30, 2005.

“We are pleased that AMEX and our lenders have granted these extensions, however, this has in no way impacted the urgency and our focus on completing the MarkWest Hydrocarbon financial statements,” said Frank Semple, President and Chief Executive Officer.  “We are continuing to work diligently with our outside auditors to complete these filings as soon as possible.”

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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, 2003, and our Forms 10-Q for 2004, as filed with the SEC.