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

                                 SCHEDULE 13G/A
                                (AMENDMENT NO. 1)

                    UNDER THE SECURITIES EXCHANGE ACT OF 1934

                          UNISOURCE ENERGY CORPORATION
                                (Name of Issuer)

                                  COMMON STOCK
                         (Title of Class of Securities)

                                    909205106
                                 (CUSIP Number)

                                DECEMBER 31, 2008
             (Date of Event Which Requires Filing of this Statement)

Check the appropriate box to designate the rule pursuant to which this Schedule
is filed:

|_|      Rule 13d-1(b)
|X|      Rule 13d-1(c)
|_|      Rule 13d-1(d)

*The remainder of this cover page shall be filled out for a reporting person's
initial filing on this form with respect to the subject class of securities, and
for any subsequent amendment containing information which would alter the
disclosures provided in a prior cover page.

The information required in the remainder of this cover page shall not be deemed
to be "filed" for the purpose of Section 18 of the Securities Exchange Act of
1934 ("Act") or otherwise subject to the liabilities of that section of the Act
but shall be subject to all other provisions of the Act (however, see the
Notes).

PERSONS WHO ARE TO RESPOND TO THE COLLECTION OF INFORMATION CONTAINED IN THIS
FORM ARE NOT REQUIRED TO RESPOND UNLESS THE FORM DISPLAYS A CURRENTLY VALID OMB
CONTROL NUMBER.


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1.    NAMES OF REPORTING PERSONS
      I.R.S. IDENTIFICATION NO. OF ABOVE PERSONS (ENTITIES ONLY)

      LUMINUS MANAGEMENT, LLC

      04-3631528
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2.    CHECK THE APPROPRIATE BOX IF A GROUP*                       (a)
                                                                  (b)  |X|
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3.    SEC USE ONLY

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4.    CITIZENSHIP OR PLACE OF ORGANIZATION

      DELAWARE, UNITED STATES OF AMERICA
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    NUMBER OF       5.  SOLE VOTING POWER                             3,296,379
      SHARES        ------------------------------------------------------------
   BENEFICIALLY     6.  SHARED VOTING POWER                                   0
     OWNED BY       ------------------------------------------------------------
       EACH         7.  SOLE DISPOSITIVE POWER                        3,296,379
    REPORTING       ------------------------------------------------------------
   PERSON WITH:     8.  SHARED DISPOSTIVE POWER                               0
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9.    AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON    3,296,379
--------------------------------------------------------------------------------
10.   CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (9) EXCLUDES CERTAIN
      SHARES (SEE INSTRUCTIONS)
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11.   PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (9)                    9.29%
--------------------------------------------------------------------------------
12.   TYPE OF REPORTING PERSON (SEE INSTRUCTIONS)                          IA
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ITEM 1. (a) Name of Issuer:
            UNISOURCE ENERGY CORPORATION

        (b) Address of Issuer's Principal Executive Offices:
            ONE SOUTH CHURCH AVENUE, SUITE 100
            TUCSON, AZ 85701

ITEM 2. (a) Name of Person Filing:
            LUMINUS MANAGEMENT, LLC

        (b) Address of Principal Business Office or, if none, Residence:
            1700 BROADWAY, 38TH FLOOR
            NEW YORK, NY 10019

        (c) Citizenship:
            DELAWARE, USA

        (d) Title of Class of Securities:
            COMMON STOCK

        (e) CUSIP Number:
            909205106

ITEM 3. If this statement is filed pursuant to ss.ss.240.13d-1(b) or
        240.13d-2(b) or (c), check whether the person filing is a:
        (a) [ ] Broker or dealer registered under section 15 of the Act
                (15 U.S.C. 78o).
        (b) [ ] Bank as defined in section 3(a)(6) of the Act (15 U.S.C. 78c).
        (c) [ ] Insurance company as defined in section 3(a)(19) of the Act
                (15 U.S.C. 78c).
        (d) [ ] Investment company registered under section 8 of the Investment
                Company Act of 1940 (15 U.S.C 80a-8).
        (e) [ ] An investment adviser in accordance with
                ss.240.13d-1(b)(1)(ii)(E);
        (f) [ ] An employee benefit plan or endowment fund in accordance with
                ss.240.13d-1(b)(1)(ii)(F);
        (g) [ ] A parent holding company or control person in accordance with
                ss.240.13d-1(b)(1)(ii)(G);
        (h) [ ] A savings associations as defined in Section 3(b) of the Federal
                Deposit Insurance Act (12 U.S.C. 1813);
        (i) [ ] A church plan that is excluded from the definition of an
                investment company under section 3(c)(14) of the Investment
                Company Act of 1940 (15 U.S.C. 80a-3);
        (j) [ ] Group, in accordance with ss.240.13d-1(b)(1)(ii)(J).

ITEM 4. OWNERSHIP.

      Provide the following information regarding the aggregate number and
percentage of the class of securities of the issuer identified in Item 1.

        (a) Amount beneficially owned:
            This statement is being filed by Luminus Management, LLC, a Delaware
            limited liability company (the "Investment Manager"), which serves
            as the investment manager to Luminus Asset Partners, L.P. and
            Luminus Energy Partners Master Fund, Ltd. (collectively the "Funds")
            with respect to the shares of Common Stock (as defined in Item 2(d))
            held by the Funds. As of December 31, 2008, Luminus Management, LLC
            beneficially owned 3,296,379 shares of Common Stock of UniSource
            Energy Corporation, which amount includes (i) 741,193 shares held by
            Luminus Asset Partners, L.P. and (ii) 2,555,186 shares held by
            Luminus Energy Partners Master Fund, Ltd.


        (b) Percent of class:
            9.29% beneficially owned by Luminus Management, LLC. Calculation of
            percentage of beneficial ownership is based on the 35,494,089 shares
            of Issuer's Common Stock outstanding as reported by the Issuer on
            its Quarterly Report filed on November 10, 2008, on Form 10-Q for
            the quarter ended September 30, 2008.

        (c) Number of shares as to which the person has:
             (i)  Sole power to vote or to direct the vote:
                  3,296,379
             (ii) Shared power to vote or to direct the vote:
                  0
            (iii) Sole power to dispose or to direct the disposition of:
                  3,296,379
             (iv) Shared power to dispose or to direct the disposition of:
                  0

ITEM 5-9 Not Applicable

Filing of this statement by the Reporting Person shall not be deemed an
admission that they beneficially own the securities reported herein as held in
customer accounts at Luminus Management, LLC or by the Funds. The Reporting
Person expressly disclaims beneficial ownership of all securities held in such
customer accounts or by the Funds. No single client's interest as reported in
the customer accounts at Luminus Management, LLC exceeds 5% of the outstanding
Common Stock of the Issuer.

ITEM 10. CERTIFICATION

The following certification shall be included if the statement is filed pursuant
to ss.240.13d-1(b):

(a)   By signing below I certify that, to the best of my knowledge and belief,
      the securities referred to above were acquired and are held in the
      ordinary course of business and were not acquired and are not held for the
      purpose of or with the effect of changing or influencing the control of
      the issuer of the securities and were not acquired and are not held in
      connection with or as a participant in any transaction having that purpose
      or effect. [X]


                                    SIGNATURE

      After reasonable 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.

                                    February 17, 2009
                                    -----------------
                                    Date

                                    /s/ Paul Segal
                                    --------------
                                    Signature

                                    Paul Segal, President
                                    ---------------------
                                    Name/Title

The original statement shall be signed by each person on whose behalf the
statement is filed or his authorized representative. If the statement is signed
on behalf of a person by his authorized representative other than an executive
officer or general partner of the filing person, evidence of the
representative's authority to sign on behalf of such person shall be filed with
the statement, provided, however, that a power of attorney for this purpose
which is already on file with the Commission may be incorporated by reference.
The name and any title of each person who signs the statement shall be typed or
printed beneath his signature.

NOTE: Schedules filed in paper format shall include a signed original and five
copies of the schedule, including all exhibits. SEE ss.240.13d-7 for other
parties for whom copies are to be sent.

ATTENTION: INTENTIONAL MISSTATEMENTS OR OMISSIONS OF FACT CONSTITUTE FEDERAL
CRIMINAL VIOLATIONS (SEE 18 U.S.C. 1001)