SECURITIES AND EXCHANGE COMMISSION
                              WASHINGTON, DC 20549

                                   FORM 12b-25

                           NOTIFICATION OF LATE FILING

                                                Commission File Number 333-21011

           (Check one)

            [ ]  Form 10-K        [ ]  Form 11-K         [ ] Form 20-F

            [X]  Form 10-Q        [ ]  Form N-SAR

                 For period ended:  June 30, 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
                                           ---------------------------

           Nothing in this form shall be construed to imply that the Commission
has verified any information contained herein.

           If the notification relates to a portion of the filing checked above,
identify the item(s) to which the notification relates:
                                                        ------------------------


                                     PART I
                             REGISTRANT INFORMATION

           Full name of registrant: FirstEnergy Corp.
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           Former name if applicable:
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           Address of principal executive office (Street and number):

           76 South Main Street
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           City, state and zip code: Akron, Ohio 44308
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                                    PART II
                             RULE 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.)

                (a)  The reasons described in reasonable detail in Part III of
                     this form could not be eliminated without unreasonable
                     effort or expense

[X]             (b)  The subject annual report, semi-annual report, transition
                     report on Form 10-K, 10-KSB, 20-F, 11-K or Form N-SAR, or
                     portion thereof will be filed on or before the 15th
                     calendar day following the prescribed due date; or the
                     subject quarterly report or transition report on Form 10-Q,
                     10-QSB, or portion thereof will be filed on of 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

           State below in reasonable detail the reasons why Form 10-K, 11-K,
20-F, 10-Q, N-SAR or the transition report portion thereof could not be filed
within the prescribed time period. (Attach extra sheets if needed.)

           The Quarterly Report on Form 10-Q for the quarter ended June 30, 2003
could not be filed within the prescribed time period due to FirstEnergy's
restatement of earnings for the year ended December 31, 2002 and the first
quarter of 2003, to reflect a change in the method of amortizing costs being
recovered under the Ohio transition plan and recognition of above-market values
of certain leased generation facilities. These changes also result in the
restatement of the 2000 and 2001 financial statements for The Cleveland Electric
Illuminating Company (CEI) and The Toledo Edison Company (TE), wholly owned
subsidiaries of FirstEnergy, but are not expected to be material to
FirstEnergy's consolidated financial results for those years. Because Arthur
Andersen LLP was CEI's and TE's auditor in 2000 and 2001 and that firm has
ceased operations, the financial statements for CEI and TE for the years ended
December 31, 2000 and 2001 must be re-audited.

                                    PART IV
                                OTHER INFORMATION

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

                  Harvey L. Wagner                       330-384-5296
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                      (Name)                    (Area Code) (Telephone Number)

         (2)      Have all other periodic reports required under Section 13 or
                  15(d) or 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 the answer is
                  no, identify report(s).   [X] Yes    [ ] No


         (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.

             FirstEnergy expects to report a net loss of $57.9 million, or
$(0.20) per share of common stock (basic and diluted), in the quarter ended June
30, 2003 compared to expected net income of $216.0 million, or basic earnings of
$0.74 per share of common stock ($0.73 diluted) in the second quarter of 2002.
Net income in the second quarter of 2003 included an after-tax charge of $67.4
million, or $0.23 per share of common stock (basic and diluted), resulting from
the abandonment of FirstEnergy's shares in Emdersa's parent company, GPU
Argentina Holdings, Inc. on April 18, 2003.

             During the first six months of 2003, net income is expected to be
$160.5 million, or basic earnings of $0.55 per share of common stock ($0.54
diluted), compared to $322.1 million, or basic earnings of $1.10 per share
($1.09 diluted) expected in the first half of 2002. Net income in the first half
of 2003 included a $60.5 million after-tax charge for discontinued operations in
Argentina and an after-tax credit of $102.1 million resulting from the
cumulative effect of an accounting change due to the adoption of Statement of
Financial Accounting Standards No. 143, "Accounting for Asset Retirement
Obligations."

             Expenses for the three months and six months ended June 30, 2003
increased due to a $158.5 million charge for costs disallowed in the JCP&L rate
case decision, the replacement power and additional nuclear expenses related to
the extended outage at the Davis-Besse Nuclear Power Station and additional
unplanned work performed during two nuclear refueling outages in the second
quarter of 2003.



FORWARD-LOOKING STATEMENT: This Form 12b-25 includes forward-looking statements
based on information currently available to management. Such statements are
subject to certain risk and uncertainties. These statements typically contain,
but are not limited to, the terms "anticipate," "potential," "expect,"
"believe," "estimate," and similar words. Actual results may differ materially
due to the speed and nature of increased competition and deregulation in the
electric utility industry, economic or weather conditions affecting future sales
and margins, changes in markets for energy services, changing energy and
commodity market prices, replacement power costs being higher than anticipated
or inadequately hedged, maintenance costs being higher than anticipated,
legislative and regulatory changes (including revised environmental
requirements), availability and cost of capital, inability of the Davis-Besse
Nuclear Power Station to restart (including because of any inability to obtain a
favorable final determination from the Nuclear Regulatory Commission) in the
fall of 2003, additional adjustments which may result from the audited
restatement of the 2002 financial statements and the restatement and review of
the first quarter of 2003 for the Company and the re-audit of 2000 and 2001
financial statements for Cleveland Electric Illuminating and Toledo Edison,
inability to accomplish or realize anticipated benefits of strategic goals and
other similar factors.




                                FIRSTENERGY CORP.
                                   Registrant

           Has caused this notification to be signed on its behalf by the
undersigned thereunto duly authorized.

Date: August 15, 2003              By /s/ Harvey L. Wagner
                                      -------------------------------------
                                          Harvey L. Wagner
                                          Vice President, Controller
                                          and Chief Accounting Officer