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

                                   FORM 12b-25


                           NOTIFICATION OF LATE FILING

                           SEC File Number: 001-16107
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           (Check one) [X]Form 10-K [ ]Form 20-F [ ]Form 11-K [ ]Form
                               10-Q [ ]Form N-SAR

                       For Period Ended: December 31, 2003

                       [ ] Transition Report on Form 10-K
                       [ ] Transition Report on Form 20-F
                       [ ] Transition Report on Form 11-K
                       [ ] Transition Report on Form 10-Q
                       [ ] Transition Report on Form N-SAR
              For the Transition Period Ended: ___________________

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Read Instruction (on back page) Before Preparing Form, Please Print or Type
Nothing  in this  form  shall be  construed  to imply  that the  Commission  has
verified any information contained herein.

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If the notification relates to a portion of the filing checked above,
identify the Item(s) to which the notification relates: N/A
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PART I -- REGISTRANT INFORMATION

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Full Name of Registrant: Mirant Corporation
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Former Name if Applicable: Southern Energy Inc.

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Address of Principal Executive Office (Street and Number, City)
1155 Perimeter Center West, Atlanta, Georgia 30338-5414

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PART II -- RULES 12b-25(b) AND (c)

If the subject report could not be filed without unreasonable effort or expense
and the registrant seeks relief pursuant to Rule 12b-25(b), the following should
be completed. (Check box if appropriate)

[X] (a)    The reasons described in reasonable detail in Part III of this
           form could not be eliminated without unreasonable effort or expense;
[ ] (b)    The subject annual report, semi-annual report, transition
           report on Form 10-K, Form 20-F,11-K or Form N-SAR, or portion
           thereof, will be Filed on or before the fifteenth calendar day
           following the prescribed due date; or the subject quarterly report of



           transition report on Form 10-Q, or portion thereof will be filed on
           or before the fifth calendar day following the prescribed due date;
           and
[ ] (c)    The accountant's statement or other exhibit required by Rule
           12b-25(c) has been attached if applicable.

PART III - NARRATIVE

         On July 14, 2003, the Company and substantially all of its wholly-owned
subsidiaries in the United States filed voluntary petitions for relief under
Chapter 11 of the Bankruptcy Code in the U.S. Bankruptcy Court for the Northern
District of Texas, Fort Worth Division. As a result of time and resources
required to support bankruptcy-related activities, additional monthly financial
reporting requirements under the Bankruptcy Code, timing of its year-end
long-lived asset impairment testing, and high employee turnover in the
organization, the Company has been unable to complete its annual financial
reporting process by the required due date. However, the Company continues to
diligently work toward completion of its annual financial reporting process and
intends to file its annual report on Form 10-K for the year ended December 31,
2003 as soon as practicably possible after completion of that process for 2003.


PART IV-- OTHER INFORMATION

(1) Name and telephone number of person to contact in regard to this
notification

   Dan Streek                          678         579-5000
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      (Name)                       (Area Code) (Telephone Number)

(2) Have all other periodic reports required under Section 13 or 15(d) of the
Securities Exchange Act of 1934 or Section 30 of the Investment Company Act of
1940 during the preceding 12 months or for such shorter period that the
registrant was required to file such report(s) been filed? If answer is no,
identify report(s). Yes [ ] No [x]

1. Form 10-K for the year ended December 31, 2002 (the Form 10-K did not include
the interim financial information required by Item 302 of Regulation S-K).
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(3) Is it anticipated that any significant change in results of operations from
the corresponding period for the last fiscal year will be reflected by the
earnings statements to be included in the subject report or portion thereof?
[X]Yes []No

If so, attach an explanation of the anticipated change, both narratively and
quantitatively, and, if appropriate, state the reasons why a reasonable estimate
of the results cannot be made.

         On July 14, 2003, the Company and substantially all of its wholly-owned
subsidiaries in the United States filed voluntary petitions for relief under
Chapter 11 of the Bankruptcy Code in the U.S. Bankruptcy Court for the Northern
District of Texas, Fort Worth Division. As such, the Company anticipates that
significant changes from the corresponding period for the prior fiscal year
could be reflected in the form of lower profitability and decreased cash flow.
As of the date of this Form 12b-25, the Company has not completed its financial
reporting process for 2003. Therefore, the Company is not in a position to
quantify any potential differences between the comparable periods. The Company



does expect, however, to record a significant impairment of long-lived assets
related to certain of its North America generation facilities. The amount of
this impairment has not yet been finalized.



                               Mirant Corporation
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                  (Name of Registrant as Specified in Charter)

has caused this notification to be signed on its behalf by the undersigned
hereunto duly authorized.


Date: March 16, 2004                       By /s/ Dan Streek
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                                               Dan Streek, Vice President and
                                               Controller
                                               (Principal Accounting Officer)