SECURITIES AND EXCHANGE COMMISSION
                             WASHINGTON, D.C. 20549

                                   FORM 8-A/A
                                 AMENDMENT NO. 6

                FOR REGISTRATION OF CERTAIN CLASSES OF SECURITIES
                     PURSUANT TO SECTION 12(b) OR (g) OF THE
                         SECURITIES EXCHANGE ACT OF 1934

                           Metretek Technologies, Inc.
             ------------------------------------------------------
             (EXACT NAME OF REGISTRANT AS SPECIFIED IN ITS CHARTER)



                                                               
                 Delaware                                                        84-1169358
--------------------------------------------                      ----------------------------------------
  (STATE OF INCORPORATION OR ORGANIZATION)                          (I.R.S. EMPLOYER IDENTIFICATION NO.)

       1675 Broadway, Suite 2150
           Denver, Colorado                                                80202
--------------------------------------------                      ----------------------
  (ADDRESS OF PRINCIPAL EXECUTIVE OFFICES)                              (ZIP CODE)


        SECURITIES TO BE REGISTERED PURSUANT TO SECTION 12(b) OF THE ACT:


                                                               
         TITLE OF EACH CLASS                                          NAME OF EACH EXCHANGE ON WHICH
         TO BE SO REGISTERED                                           EACH CLASS IS TO BE REGISTERED
         ---------------------                                    ---------------------------------------
                  None                                                             None


IF THIS FORM RELATES TO THE REGISTRATION OF A CLASS OF SECURITIES PURSUANT TO
SECTION 12(B) OF THE EXCHANGE ACT AND IS EFFECTIVE PURSUANT TO GENERAL
INSTRUCTION A.(C), PLEASE CHECK THE FOLLOWING BOX. [ ]

IF THIS FORM RELATES TO THE REGISTRATION OF A CLASS OF SECURITIES PURSUANT TO
SECTION 12(G) OF THE EXCHANGE ACT AND IS EFFECTIVE PURSUANT TO GENERAL
INSTRUCTION A.(D), PLEASE CHECK THE FOLLOWING BOX. [X]

 SECURITIES ACT REGISTRATION STATEMENT FILE NUMBER TO WHICH THIS FORM RELATES:
                                 Not applicable

             SECURITIES TO BE REGISTERED PURSUANT TO SECTION 12(g)
                                  OF THE ACT:

                        Preferred Share Purchase Rights
                        -------------------------------
                                (TITLE OF CLASS)





         This Form 8-A/A Amendment No. 6 is hereby filed to supplement and amend
the information set forth in the Form 8-A filed by Metretek Technologies, Inc.
(formerly known as Marcum Natural Gas Services, Inc.) on January 10, 1992, as
previously amended, including by Form 8-A/A Amendment No. 5 filed on November
30, 2001.

ITEM 1.  DESCRIPTION OF REGISTRANT'S SECURITIES TO BE REGISTERED
         -------------------------------------------------------

         On May 3, 2004, Metretek Technologies, Inc., a Delaware corporation
(the "Company"), issued 3,510,548 shares of its common stock, par value $.01 per
share ("Common Shares"), and five-year warrants to purchase 702,109 shares of
its Common Stock in a private placement (the "Private Placement") to certain
institutional and accredited investors ("2004 Private Placement Investors"). The
Private Placement was made pursuant to a Securities Purchase Agreement, dated as
of April 29, 2004, among the Company and certain investors (the "Securities
Purchase Agreement"). In addition, certain holders ("Series B Preferred
Shareholders") of outstanding shares of the Company's Series B Preferred Stock,
par value $.01 per share ("Series B Preferred Shares") have agreed to convert a
total of 2,500 shares of Preferred Stock, including accrued and unpaid
dividends, and to receive upon such conversion approximately 1,209,000 shares of
Common Stock plus warrants to purchase approximately 1,209,000 million shares of
Common Stock exercisable until June 9, 2005 at an exercise price of $3.0571 per
share, which is the same price as the conversion price of the Preferred Stock
into each share of Common Stock, pursuant to certain documents (the "Series B
Preferred Share Documents").

         Pursuant to the authorization of the Company's Board of Directors, and
in order to prevent the Private Placement and the Series B Preferred Share
Documents or the acquisition of Common Shares or warrants by the 2004 Private
Placement Investors in connection with the Private Placement or by the Series B
Preferred Shareholders in connection with the Series B Preferred Share Documents
or upon the exercise of the warrants, from triggering the protections provided
by the Amended and Restated Rights Agreement, dated as of November 30, 2001 (the
"Rights Agreement"), on April 22, 2004, the Company adopted and entered into
Amendment No. 1 ("Amendment No. 1") to the Rights Agreement. All capitalized
terms used below but not defined herein have the respective meanings given to
them in the Rights Agreement.

         Amendment No. 1 provides as follows:

         o    Sections 1(a), 1(jj), 3(a), 11 and 13 of the Rights Agreement are
              amended to:

              (a) prevent any 2004 Private Placement Investors or Series B
              Preferred Shareholders and their Affiliates and Associates from
              becoming an "Acquiring Person",

              (b) prevent a "Shares Acquisition Date" from occurring,

              (c) prevent a "Distribution Date" from occurring, and


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              (d) prevent any adjustment of the purchase price, number and kind
              of shares, number of rights or other protection set forth in
              Sections 11 and 13 from being triggered;

              in each case, as the result of:

                           (i) the execution and delivery of the Securities
                           Purchase Agreement and all related agreements and
                           instruments (collectively referred as the "2004
                           Private Placement Documents"), or of the Series B
                           Preferred Share Documents, or any amendments thereto
                           in accordance with the terms thereof,

                           (ii) any actions taken by any of the 2004 Private
                           Placement or any of the Investors Series B Preferred
                           Shareholders pursuant to the terms of any of the 2004
                           Private Placement Documents or the Series B Preferred
                           Share Documents,

                           (iii) the consummation of the transactions
                           contemplated by the 2004 Private Placement Documents
                           or the Series B Preferred Share Documents, or

                           (iv) the announcement or commencement thereof,
                           including, without limitation, the acquisition by any
                           of the 2004 Private Placement Investors or any of the
                           Series B Preferred Shareholders now or at any time in
                           the future of any Common Shares, warrants, and Common
                           Shares issued or issuable upon exercise of warrants,
                           or any other acquisition of any such securities, in
                           each case pursuant to the 2004 Private Placement
                           Documents or the Series B Preferred Share Documents.

         A copy of Amendment No. 1 is being filed as Exhibit 1 to this Form
8-A/A, Amendment No. 6 and is incorporated herein by reference. The foregoing
description of Amendment No. 1 does not purport to be complete and is qualified
in its entirety by reference to Amendment No. 1.


ITEM 2.  EXHIBITS.

         1.       Form of Amendment No. 1 to Rights Agreement, dated April 22,
                  2004, between Metretek Technologies, Inc. and ComputerShare
                  Investor Services, LLC. *



         -----------------
         * Filed herewith



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                                    SIGNATURE

         Pursuant to the requirements of Section 12 of the Securities Exchange
Act of 1934, the Registrant has duly caused this Registration Statement to be
signed on its behalf by the undersigned, thereunto duly authorized.

                                       METRETEK TECHNOLOGIES, INC.



Date:  May 21, 2004                    By /s/ W. Phillip Marcum
                                          -------------------------------------
                                          W. Phillip Marcum, President and
                                          Chief Executive Officer



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