<PAGE>
AS FILED WITH THE SECURITIES AND EXCHANGE COMMISSION ON SEPTEMBER 14, 2000
REGISTRATION NO. 333-43908
--------------------------------------------------------------------------------
--------------------------------------------------------------------------------
SECURITIES AND EXCHANGE COMMISSION
WASHINGTON, D.C. 20549
------------------------
POST EFFECTIVE
AMENDMENT NO. 1
TO
FORM S-4
REGISTRATION STATEMENT
UNDER
THE SECURITIES ACT OF 1933
------------------------
THE AES CORPORATION
(Exact name of registrant as specified in its charter)
<TABLE>
<S> <C> <C>
DELAWARE 4991 54-1163725
(State or other jurisdiction (Primary Standard Industrial (I.R.S. Employer
of incorporation or organization) Classification Code Number) Identification No.)
</TABLE>
------------------------
1001 NORTH 19TH STREET
ARLINGTON, VIRGINIA 22209
(703) 522-1315
(Address, including zip code, and telephone number,
including area code, of registrant's principal executive offices)
------------------------
BARRY J. SHARP
SENIOR VICE PRESIDENT AND CHIEF FINANCIAL OFFICER
THE AES CORPORATION
1001 NORTH 19TH STREET
ARLINGTON, VIRGINIA 22209
(703) 522-1315
(Name, address, including zip code, and telephone number, including area code,
of agent for service)
------------------------
COPIES TO:
<TABLE>
<S> <C>
RONALD C. BARUSCH, ESQ. RICHARD HALL, ESQ.
PANKAJ K. SINHA, ESQ. CRAVATH, SWAINE & MOORE
SKADDEN, ARPS, SLATE, MEAGHER & FLOM LLP 825 EIGHTH AVENUE
1440 NEW YORK AVENUE, N.W. NEW YORK, NEW YORK 10019
WASHINGTON, D.C. 20005 (212) 474-1000
(202) 371-7000
</TABLE>
------------------------
APPROXIMATE DATE OF COMMENCEMENT OF THE PROPOSED SALE OF THE SECURITIES TO
THE PUBLIC: As soon as practicable following the effectiveness of this
Registration Statement and after all other conditions under the share exchange
agreement are satisfied or waived.
If the securities being registered on this form are to be offered in
connection with the formation of a holding company and there is compliance with
General Instruction G, check the following box. / /
If this form is filed to register additional securities for an offering
pursuant to Rule 462(b) under the Securities Act of 1933, as amended (the
"Securities Act"), check the following box and list the Securities Act
registration statement number of the earlier effective registration statement
for the same offering. / /
If this form is a post-effective amendment filed pursuant to Rule 462(d)
under the Securities Act, check the following box and list the Securities Act
registration statement number of the earlier effective registration statement
for the same offering. /X/ Registration No. 333-43908
------------------------
--------------------------------------------------------------------------------
--------------------------------------------------------------------------------
<PAGE>
EXPLANATORY NOTE
This Post-Effective Amendment No. 1 (the "Amendment") to the Registration
Statement on Form S-4 (File No. 333-43908) of The AES Corporation (the
"Registration Statement") is being filed pursuant to Rule 462(d) under the
Securities Act of 1933, as amended, for the sole purpose of filing an additional
exhibit to the Registration Statement and, accordingly, shall become effective
immediately upon filing with the Securities and Exchange Commission (the
"Commission"). After giving effect to this Amendment, the Registration Statement
consists of the Registration Statement as filed with the Commission at the time
it became effective on September 7, 2000, as supplemented by this Amendment.
<PAGE>
ITEM 21. EXHIBITS AND FINANCIAL STATEMENT SCHEDULES
<TABLE>
<CAPTION>
EXHIBIT
NUMBER DESCRIPTION
--------------------- -----------
<C> <S>
2.1 Agreement and Plan of Share Exchange dated as of July 15,
2000, between The AES Corporation and IPALCO Enterprises,
Inc. (included as Annex A to the proxy statement/
prospectus).
2.2 Opinion of UBS Warburg LLC (included as Annex B to the proxy
statement/prospectus).
3.1 Sixth Amended and Restated Certificate of Incorporation of
The AES Corporation (incorporated by reference to Exhibit
3.1 to The AES Corporation Quarterly Report on Form 10-Q
filed May 15, 2000).
3.2 The AES Corporation By-laws, as amended (incorporated by
reference to Exhibit 3.2 to The AES Corporation Quarterly
Report on Form 10-Q filed August 14, 1998).
5.1 Opinion of Skadden, Arps, Slate, Meagher & Flom LLP
regarding the legality of the securities.
8.1 Opinion of Skadden, Arps, Slate, Meagher & Flom LLP
regarding tax matters.
8.2 Opinion of Cravath, Swaine & Moore regarding tax matters.
23.1 Consent of Skadden, Arps, Slate, Meagher & Flom LLP (set
forth in Exhibit 5.1).
23.2 Consent of Skadden, Arps, Slate, Meagher & Flom LLP (set
forth in Exhibit 8.1).
23.3 Consent of Cravath, Swaine & Moore (set forth in Exhibit
8.2).
23.4 Consent of Deloitte & Touche LLP (AES).
23.5 Consent of Deloitte & Touche LLP (IPALCO).
23.6* Consent of UBS Warburg LLC.
24.1 Powers of Attorney.
99.1 Form of IPALCO Enterprises, Inc. Proxy.
99.2 Form of Instruction to Thrift Plan Trustee.
</TABLE>
------------------------
* Filed herewith
II-1
<PAGE>
SIGNATURES
Pursuant to the requirements of the Securities Act of 1933, as amended, the
registrant has duly caused this Post-Effective Amendment No. 1 to the
Registration Statement on Form S-4 to be signed on its behalf by the
undersigned, thereunto duly authorized, in Arlington, Virginia, on the 13th day
of September, 2000.
<TABLE>
<S> <C> <C>
THE AES CORPORATION
By: /s/ WILLIAM R. LURASCHI
-----------------------------------------
William R. Luraschi
Vice President and Secretary
</TABLE>
Pursuant to the requirements of the Securities Act of 1933, this
Post-Effective Amendment No. 1 to the Registration Statement has been signed by
the following persons in the capacities and on the dates indicated.
<TABLE>
<CAPTION>
SIGNATURE TITLE DATE
--------- ----- ----
<S> <C> <C>
* September 13, 2000
------------------------------------------- Chairman of the Board
Roger W. Sant
* President, Chief Executive September 13, 2000
------------------------------------------- Officer (principal
Dennis W. Bakke executive
officer) and Director
* September 13, 2000
------------------------------------------- Director
Dr. Alice F. Emerson
* September 13, 2000
------------------------------------------- Director
Robert F. Hemphill, Jr.
* September 13, 2000
------------------------------------------- Director
Frank Jungers
* September 13, 2000
------------------------------------------- Director
John H. McArthur
</TABLE>
II-2
<PAGE>
<TABLE>
<CAPTION>
SIGNATURE TITLE DATE
--------- ----- ----
<S> <C> <C>
* September 13, 2000
------------------------------------------- Director
Hazel R. O'Leary
* September 13, 2000
------------------------------------------- Director
Thomas I. Unterberg
* September 13, 2000
------------------------------------------- Director
Robert H. Waterman, Jr.
* Senior Vice President and September 13, 2000
------------------------------------------- Chief Financial Officer
Barry J. Sharp (principal financial and
accounting officer)
</TABLE>
<TABLE>
<S> <C> <C>
*By: /s/ WILLIAM R. LURASCHI
-------------------------------------
William R. Luraschi
Attorney-in-fact
</TABLE>
II-3
<PAGE>
EXHIBIT INDEX
<TABLE>
<CAPTION>
EXHIBIT
NUMBER DESCRIPTION
--------------------- -----------
<C> <S>
2.1 Agreement and Plan of Share Exchange dated as of July 15,
2000, between The AES Corporation and IPALCO Enterprises,
Inc. (included as Annex A to the proxy statement/
prospectus).
2.2 Opinion of UBS Warburg LLC (included as Annex B to the proxy
statement/prospectus).
3.1 Sixth Amended and Restated Certificate of Incorporation of
The AES Corporation (incorporated by reference to Exhibit
3.1 to The AES Corporation Quarterly Report on Form 10-Q
filed May 15, 2000).
3.2 The AES Corporation By-laws, as amended (incorporated by
reference to Exhibit 3.2 to The AES Corporation Quarterly
Report on Form 10-Q filed August 14, 1998).
5.1 Opinion of Skadden, Arps, Slate, Meagher & Flom LLP
regarding the legality of the securities.
8.1 Opinion of Skadden, Arps, Slate, Meagher & Flom LLP
regarding tax matters.
8.2 Opinion of Cravath, Swaine & Moore regarding tax matters.
23.1 Consent of Skadden, Arps, Slate, Meagher & Flom LLP (set
forth in Exhibit 5.1).
23.2 Consent of Skadden, Arps, Slate, Meagher & Flom LLP (set
forth in Exhibit 8.1).
23.3 Consent of Cravath, Swaine & Moore (set forth in Exhibit
8.2).
23.4 Consent of Deloitte & Touche LLP (AES).
23.5 Consent of Deloitte & Touche LLP (IPALCO).
23.6* Consent of UBS Warburg LLC.
24.1 Powers of Attorney.
99.1 Form of IPALCO Enterprises, Inc. Proxy.
99.2 Form of Instruction to Thrift Plan Trustee.
</TABLE>
------------------------
* Filed herewith
