<PAGE>
================================================================================
SECURITIES AND EXCHANGE COMMISSION
WASHINGTON, D.C. 20549
---------------------------
SCHEDULE TO/A
(RULE 14d-100)
TENDER OFFER STATEMENT UNDER SECTION 14(d)(1) OR SECTION 13(e)(1)
OF THE SECURITIES EXCHANGE ACT OF 1934
(AMENDMENT NO. 8)
---------------------------
GENER S.A.
(Name of Subject Company (Issuer))
---------------------------
THE AES CORPORATION
MERCURY CAYMAN CO. III, LTD.
(Name of Filing Persons (Offerors))
---------------------------
AMERICAN DEPOSITARY SHARES (EACH REPRESENTING 68 SHARES
OF COMMON STOCK, NO PAR VALUE)
(Title of Class of Securities)
---------------------------
368731105
(CUSIP Number of Class of Securities)
---------------------------
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 and Telephone Number of Person
Authorized to Receive Notices and Communications On Behalf of Filing Persons)
---------------------------
Copy To:
Michael E. Gizang, Esq.
Skadden, Arps, Slate, Meagher & Flom LLP
Four Times Square
New York, New York 10036
Telephone: (212) 735-3000
---------------------------
CALCULATION OF FILING FEE
TRANSACTION VALUATION* AMOUNT OF FILING FEE**
$181,634,952.00 $36,327.00
================================================================================
<PAGE>
--------------------------------------------------------------------------------
* Estimated for purposes of calculating the amount of the filing fee only in
accordance with Rules 0-11(d) and 0-11(a)(4) under the Securities Exchange
Act of 1934, based upon (a) $12.25, the average of the high and low price
per Gener American Depositary Share On November 2, 2000, as reported on the
New York Stock Exchange Composite Transaction Tape, multiplied by (b)
14,827,343, representing the aggregate number of Gener American Depositary
Shares outstanding on September 30, 2000.
** One-fiftieth of 1% of the value of the transaction.
[X] Check the box if any part of the fee is offset as provided by rule
0-11(a)(2) and identify the filing with which the offsetting fee was
previously paid. identify the previous filing by registration statement
number, or the Form or Schedule and the date of its filing.
Amount Previously Paid: $36,327.00
Form or Registration No.: Registration Statement On Form S-4
Filing Party: the AES Corporation
Date Filed: November 9, 2000
[ ] Check the box if the filing relates solely to preliminary communications
made before the commencement of a tender offer.
Check the appropriate boxes below to designate any transactions to which
the statement relates:
[X] third-party tender offer subject to Rule 14d-1.
[ ] issuer tender offer subject to Rule 13e-4.
[ ] going-private transaction subject to Rule 13e-3.
[ ] amendment to schedule 13D under Rule 13d-2.
Check the following box if the filing is a final amendment reporting the
results of the tender offer: [ ]
This Amendment No. 8 amends and supplements the Tender Offer Statement on
Schedule TO initially filed on November 9, 2000 (the "Schedule TO") by Mercury
Cayman Co. III, Ltd., a limited company organized under the laws of the Cayman
Islands (the "Purchaser") and a wholly owned subsidiary of The AES Corporation,
a Delaware corporation ("AES"), relating to the offer by the Purchaser to
exchange each issued and outstanding American Depositary Share (each, an "ADS"
and collectively, "ADSs") of Gener S.A. ("Gener"), each representing 68 shares
of Gener common stock, no par value (the "Shares"), for a fraction of a share of
common stock, par value $ 0.01 per share, of AES (the "AES Shares"), on the
terms and subject to the conditions described in the Prospectus (as defined
below), as amended by Amendment No. 5 thereto, dated December 8, 2000 (the
"Fifth Amendment"), Amendment No. 6 thereto, dated December 13, 2000 (the "Sixth
Amendment"), and Amendment No. 7 thereto, dated December 14, 2000 (the "Seventh
Amendment"), and the related ADS Letter of Transmittal (collectively referred to
as the "Offer").
AES initially filed a Registration Statement on Form S-4 relating to the
AES Shares to be issued to holders of Gener ADSs in the Offer on November 9,
2000 (the "Registration Statement"), which has subsequently been amended by
Amendment No. 1 thereto, dated December 7, 2000, Amendment No. 2 thereto, dated
December 13, 2000, and Amendment No. 3 thereto, dated December 14, 2000. The
terms and conditions of the Offer are set forth in the preliminary prospectus
dated December 7, 2000, which is a part of the Registration Statement as amended
(the "Prospectus"), and the related Letter of Transmittal, which are annexed to
the Schedule TO as Exhibits (a)(13) and (a)(2), respectively.
All of the information in the Prospectus, the Fifth Amendment, the Sixth
Amendment, the Seventh Amendment and the related ADS Letter of Transmittal, and
any prospectus supplement or other supplement or amendment thereto related to
the Offer hereafter filed with the Securities and Exchange Commission by AES, is
hereby incorporated by reference in answer to Items 2 through 11 of this
Schedule TO.
2
<PAGE>
ITEM 4. TERMS OF THE TRANSACTION.
Item 4 is hereby amended and supplemented as follows:
The section of the Prospectus entitled "OUR OFFER-Extension, Termination
and Amendment" is hereby amended and supplemented by adding the following
sentence after the second paragraph of the section:
"We announced in a press release on December 20, 2000 that the Santiago
Stock Exchange auction transaction, or remate, in connection with the Chilean
offer had been scheduled to be held on Thursday, December 28, 2000."
ITEMS 4 AND 11.
Items 4 and 11 are hereby amended and supplemented as follows:
The section of the Prospectus entitled "SUMMARY-Our Offer-Timing of Our
Offer" is hereby amended and supplemented by adding the following sentence after
the second paragraph of the section:
"We announced in a press release on December 20, 2000 that the Santiago
Stock Exchange auction transaction, or remate, in connection with the Chilean
offer had been scheduled to be held on Thursday, December 28, 2000."
ITEM 11. ADDITIONAL INFORMATION.
Item 11 is hereby amended and supplemented as follows:
On December 20, 2000, we announced in a press release that we have extended
the expiration date of the U.S. exchange offer so that it is now scheduled to
expire at 3:00 p.m. on Friday, December 29, 2000. We also announced that, as of
the close of business on December 19, 2000, 11,407,276 ADSs had been tendered
and not withdrawn pursuant to the exchange offer. A copy of the press release is
filed herewith as Exhibit (a)(17) and the information set forth in the press
release is incorporated herein by reference.
The section of the Prospectus entitled "THE CHILEAN OFFER" is hereby
amended and supplemented by adding the following sentence after the first
paragraph of the section:
"We announced in a press release on December 20, 2000 that the Santiago
Stock Exchange auction transaction, or remate, in connection with the Chilean
offer had been scheduled to be held on Thursday, December 28, 2000."
ITEM 12. EXHIBITS.
Item 12 is hereby amended and supplemented to add the following exhibits:
(a)(17) Press release dated December 20, 2000.
3
<PAGE>
SIGNATURE
After due inquiry and to the best of my knowledge and belief, we certify
that the information set forth in this statement is true, complete and correct.
MERCURY CAYMAN CO. III, LTD.
By: /s/ Naveed Ismail
---------------------------------
Name: Naveed Ismail
Title: President
Dated: December 21, 2000
THE AES CORPORATION
By: /s/ Paul T. Hanrahan
---------------------------------
Name: Paul T. Hanrahan
Title: Senior Vice President
Dated: December 21, 2000
4
<PAGE>
EXHIBIT INDEX
EXHIBIT
NUMBER EXHIBIT NAME
------ ------------
(a)(1) Prospectus relating to AES Shares to be issued in the U.S. Offer
(incorporated by reference from The AES Corporation Registration
Statement on Form S-4 filed on November 9, 2000).*
(a)(2) Form of ADS Letter of Transmittal (incorporated by reference to
Exhibit 99.1 to The AES Corporation Registration Statement on
Form S-4 filed on November 9, 2000).*
(a)(3) Form of Notice of Guaranteed Delivery (incorporated by reference
to Exhibit 99.2 to The AES Corporation Registration Statement on
Form S-4 filed on November 9, 2000).*
(a)(4) Form of Letter to Brokers, Dealers, Commercial Banks, Trust
Companies and Other Nominees (incorporated by reference to
Exhibit 99.3 to The AES Corporation Registration Statement on
Form S-4 filed on November 9, 2000).*
(a)(5) Form of Letter to Clients for use by Brokers, Dealers, Commercial
Banks, Trust Companies and Other Nominees (incorporated by
reference to Exhibit 99.4 to The AES Corporation Registration
Statement on Form S-4 filed on November 9, 2000).*
(a)(6) Guidelines for Certification of Taxpayer Identification Number on
Substitute Form W-9 (incorporated by reference to Exhibit 99.5 to
The AES Corporation Registration Statement on Form S-4 filed on
November 9, 2000).*
(a)(7) Summary Advertisement published in The Wall Street Journal on
November 13, 2000 (incorporated by reference to Exhibit 99.6 to
The AES Corporation Registration Statement on Form S-4 filed on
November 9, 2000).*
(a)(8) Press Release issued by AES on November 3, 2000 (incorporated by
reference to Exhibit 99.7 to The AES Corporation Registration
Statement on Form S-4 filed on November 9, 2000).*
(b) None.
(d) Letter Agreement between AES and Compania de Petroleos de Chile
S.A., dated November 3, 2000.*
(g) None.
(h) None.
(a)(9) Press release dated November 22, 2000.*
(a)(10) Press release dated November 28, 2000.*
(a)(11) Agreement, dated as of November 28, 2000, between AES,
TotalFinaElf, and Total Gas and Power Ventures.*
(a)(12) Press release dated December 7, 2000.*
(a)(13) Preliminary Prospectus, dated December 7, 2000, relating to AES
Shares to be issued in Offer (incorporated by reference from
Amendment No. 1 to AES's Registration Statement on S-4 filed on
December 7, 2000).*
(a)(14) Press release dated December 8, 2000.*
(a)(15) Press release dated December 12, 2000.*
(a)(16) Supplement No. 1 to the Prospectus relating to AES shares to be
issued in the U.S. Offer.*
(a)(17) Press release dated December 20, 2000.
* Previously filed.
