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) [ ]Form 10-K [ ]Form 20-F [ ]Form 11-K
                           [X]Form 10-Q [ ]Form N-SAR

                  For Period Ended: March 31, 2004

                           [ ] 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 was unable to timely complete its annual financial
reporting process for 2003. The Form 10-K for the year ended December 31, 2003
was filed on April 19, 2004. For those reasons, the Company was unable to timely
complete its financial reporting process for the quarter ended March 31, 2004.
However, the Company continues to diligently work toward completion of its
financial reporting process and intends to file its quarterly report on Form
10-Q for the quarter ended March 31, 2004 as soon as practicably possible after
completion of its financial reporting process for that quarter.

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 [X] No [ ]

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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 the first quarter of 2004. Therefore, the Company is not
in a position to quantify any potential differences between the comparable
periods.

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                               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: May 11, 2004                             By /s/ Dan Streek
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                                               Dan Streek, Vice President and
                                               Controller
                                               (Principal Accounting Officer)