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                                  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) May 14, 2003

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



              Delaware            1-11566             84-1352233
(State or other jurisdiction (Commission File Number)  (I.R.S. Employer
incorporation or organization)                     Identification Number)



        155 Inverness Drive West, Suite 200, Englewood, CO 80112-5000
                   (Address of principal executive offices)


       Registrant's telephone number, including area code: 303-290-8700








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ITEM 7.     FINANCIAL STATEMENTS AND EXHIBITS

(c)  Exhibits

      99.1  Press Release dated May 14, 2003


ITEM 9. REGULATION FD DISCLOSURE (INFORMATION PROVIDED UNDER ITEM 12. RESULTS
OF OPERATIONS AND FINANCIAL CONDITION).

      On May 14, 2003, MarkWest Hydrocarbon, Inc. (the "Company") announced its
consolidated financial results for the quarter ended March 31, 2003. A copy of
the Company's earnings press release is furnished as Exhibit 99.1 to this report
on Form 8-K. The information contained in this report on Form 8-K, including
Exhibit 99.1, is being furnished pursuant to Item 12 of Form 8-K under Item 9 of
Form 8-K as directed by the Securities and Exchange Commission in Release No.
34-47583. The information contained in this report on Form 8-K, including
Exhibit 99.1, shall not be deemed "filed" with the Securities and Exchange
Commission nor incorporated by reference in any registration statement filed by
the Company under the Securities Act of 1933, as amended.





                                   SIGNATURES

      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:   May 14, 2003                   By:  /s/ Donald C. Heppermann
                                           -------------------------------------
                                             Donald C. Heppermann, Senior
                                             Vice President, Chief Financial
                                             Officer and Secretary