================================================================================






                               THE AES CORPORATION

                                       AND

                       THE FIRST NATIONAL BANK OF CHICAGO

                                   as Trustee

                              --------------------

                          FIRST SUPPLEMENTAL INDENTURE

                           Dated as of August 10, 1998

                                       TO

                          JUNIOR SUBORDINATED INDENTURE

                           Dated as of August 10, 1998

                              --------------------

                4.50% Convertible Junior Subordinated Debentures

                                    due 2005

================================================================================








     The First Supplemental INDENTURE, dated as of this 10th day of August, 1998
(the "First Supplemental Indenture"), between THE AES CORPORATION, a corporation
duly organized and existing under the laws of the State of Delaware (hereinafter
sometimes referred to as the "Company"), and THE FIRST NATIONAL BANK OF CHICAGO,
a national banking association, as trustee (hereinafter sometimes referred to as
the "Trustee")  under the Junior  Subordinated  Indenture dated as of August 10,
1998 between the Company and the Trustee (the "Indenture");

     WHEREAS, the Company executed and delivered the Indenture to the Trustee to
provide  for the future  issuance  of its junior  subordinated  securities  (the
"Debentures"), said Debentures to be issued from time to time in series as might
be  determined  by the Company under the  Indenture,  in an unlimited  aggregate
principal amount which may be authenticated  and delivered  thereunder as in the
Indenture provided; and

     WHEREAS,  pursuant to the terms of the  Indenture,  the Company  desires to
provide for the  establishment  of a new series of its Debentures to be known as
its 4.50% Convertible Junior Subordinated Debentures due 2005 (said series being
hereinafter referred to as the "Series A Convertible Debentures"),  the form and
substance of such Series A Convertible Debentures and the terms,  provisions and
conditions  thereof to be set forth as provided in the  Indenture and this First
Supplemental Indenture; and

     WHEREAS,  the Company desires and has requested the Trustee to join with it
in the  execution  and delivery of this First  Supplemental  Indenture,  and all
requirements  necessary  to  make  this  First  Supplemental  Indenture  a valid
instrument,  in accordance with its terms,  and to make the Series A Convertible
Debentures,  when executed by the Company and authenticated and delivered by the
Trustee, the valid obligations of the Company have been performed and fulfilled,
and the execution and delivery hereof have been in all respects duly authorized;

     NOW,  THEREFORE,  in  consideration  of the purchase and  acceptance of the
Series A Convertible  Debentures by the holders thereof,  and for the purpose of
setting  forth,  as provided in the  Indenture,  the form and  substance  of the
Series  A  Convertible  Debentures  and the  terms,  provisions  and  conditions
thereof, the Company covenants and agrees with the Trustee as follows:







                                   ARTICLE ONE

                        DEFINITIONS AND OTHER PROVISIONS
                             OF GENERAL APPLICATION

     SECTION 1.1. TERMS DEFINED IN THE INDENTURE.

     Each  capitalized  term used not but  defined  in this  First  Supplemental
Indenture shall have the meaning assigned to such term in the Indenture.

     SECTION 1.2. CERTAIN DEFINITIONS.

     The following  definitions are hereby added to the definitions contained in
Section 1.1 of the Indenture,  but only with respect to the Series A Convertible
Debentures issued in accordance with the provisions hereof:

     "Common Stock" means the Common Stock, $.01 par value, of the Company.

     "Repurchase  Event"  means  the  occurrence  of a Change  in  Control  or a
Termination of Trading.

     "Senior  Subordinated  Debt" means Debt which is  subordinated  in right of
payment only to Debt which is not subordinated and includes, without limitation,
the  Company's  8.375% Senior  Subordinated  Debentures  due 2027,  8.50% Senior
Subordinated  Notes  due 2007,  8.375%  Senior  Subordinated  Notes due 2007 and
10.25% Senior Subordinated Notes due 2006.

     "Termination  of Trading"  occurs if the Common Stock (or if the Debentures
are not then  convertible  into Common Stock,  any other common stock into which
the  Debentures  are then  convertible)  is neither listed for trading on a U.S.
national  securities  exchange  nor  approved  for  trading  on  an  established
automated over-the-counter trading market in the United States.

     "Trading Date" means each Monday, Tuesday, Wednesday,  Thursday and Friday,
other  than  any day on  which  securities  are  not  traded  on the  applicable
securities exchange or in the applicable securities market.

     The following terms are defined in the places indicated:


                                       2





         Term                                            Defined in Section
         ----                                            ------------------
         Closing Price                                            5.4
         conversion price                                         5.1
         Current Market Price                                     5.4
         Purchased Shares                                         5.4

                                   ARTICLE TWO

                       THE SERIES A CONVERTIBLE DEBENTURES

     SECTION 2.1. FORM.

     The Series A Convertible  Debentures  shall be substantially in the form of
Exhibit A hereto, which is a part of this First Supplemental  Indenture, in each
case  with  such  appropriate  insertions,  omissions,  substitutions  and other
variations  as are  required  or  permitted  by the  Indenture  and  this  First
Supplemental  Indenture,  and may have such  letters,  numbers or other marks of
identification  and  such  legends  or  endorsements  placed  thereon  as may be
required  to  comply  with  the  rules  of any  securities  exchange  or as may,
consistently  herewith,  be determined by the officers of the Company  executing
such Series A  Convertible  Debentures,  as evidenced by their  execution of the
Series A Convertible Debentures.

     The Series A Convertible  Debentures will initially be issued as Registered
Global Securities.

     The Company initially appoints The Depository Trust Company and the Trustee
to act as Depositary and Securities Custodian, respectively, with respect to the
Series A Convertible Debentures.

     The  Company  initially  appoints  the  Trustee to act as Paying  Agent and
Registrar with respect to the Series A Convertible Debentures.

     SECTION 2.2. DESIGNATION AND AMOUNT.

     (a) The  Series A  Convertible  Debentures  shall be  entitled  the  "4.50%
Convertible Junior Subordinated Debentures due 2005" of the Company.

     (b) The  Trustee  shall  authenticate  and  deliver  Series  A  Convertible
Debentures for original issue in an aggregate  principal amount of $150,000,000;
provided,  however, that in the event the Company sells any Series A Convertible
Deben-


                                       3





tures  pursuant  to the  over-allotment  option  (the  "Over-Allotment  Option")
granted pursuant to the Underwriting  Agreement dated August 4, 1998 between the
Company,  Smith Barney Inc., J.P. Morgan Securities,  Inc., Donaldson,  Lufkin &
Jenrette Securities Corporation, Morgan Stanley & Co. Incorporated,  PaineWebber
Incorporated and C.E. Unterberg, Towbin, then the Trustee shall authenticate and
deliver  Series A  Convertible  Debentures  for  original  issue in an aggregate
principal  amount of  $150,000,000  plus up to $22,500,000  aggregate  principal
amount of Series A Convertible  Debentures  sold pursuant to the  Over-Allotment
Option. The aggregate  principal amount of Series A Convertible  Debentures that
may be authenticated and delivered under the Indenture may not exceed the amount
set forth in the foregoing sentence,  subject to the proviso therein, except for
Series A Convertible  Debentures  that may be  authenticated  and delivered upon
registration  of transfer of, or in exchange  for, or in lieu of, other Series A
Convertible  Debentures  pursuant to Sections 2.7, 2.8,  2.10, 3.3 or 9.4 of the
Indenture and Section 4.1 of this First Supplemental Indenture.

     (c) The Company may not issue new Debentures to replace  Debentures that it
has paid or  delivered  to the Trustee for  cancellation  or that any Holder has
converted pursuant to Article Five.

     SECTION 2.3. INTEREST.

     Interest  on the Series A  Convertible  Debentures  shall be payable on the
dates and in the manner  provided  for in the form of the  Series A  Convertible
Debenture attached hereto as Exhibit A.

     SECTION 2.4. DENOMINATIONS.

     The Debentures shall be Registered Securities in denominations of $1,000 or
any integral multiple thereof.

     SECTION 2.5. PLACE OF PAYMENT.

     The place of payment for the Series A Convertible  Debentures  shall be the
Borough of Manhattan,  The City of New York. So long as the Series A Convertible
Debentures are in the form of Registered Global  Securities,  the Company agrees
that  payments of interest on, and any portion of the principal of, the Holder's
Series A Convertible  Debenture shall be made by the Paying Agent,  upon receipt
from the Company of immediately  available funds, directly to the Depositary (by
Federal funds wire transfer).


                                       4





                                  ARTICLE THREE

           OPTIONAL REDEMPTION OF THE SERIES A CONVERTIBLE DEBENTURES

     SECTION 3.1. OPTIONAL REDEMPTION.

     The Series A Convertible  Debentures may be redeemed at the election of the
Company as provided by the terms of the Series A  Convertible  Debentures,  as a
whole or from time to time in part,  at the times and at the  Redemption  Prices
specified in the form of the Series A Convertible  Debentures attached hereto as
Exhibit A, together with any applicable accrued interest to the Redemption Date.

                                  ARTICLE FOUR

                       ADDITIONAL COVENANTS APPLICABLE TO
                         SERIES A CONVERTIBLE DEBENTURES

     SECTION 4.1. REPURCHASE EVENT.

     (a) In the  event  of a  Repurchase  Event,  each  Holder  of the  Series A
Convertible  Debentures shall have, subject to Article 11 of the Indenture,  the
right, at such Holder's  option,  to require that the Company  repurchase all or
any part of such Holder's Series A Convertible  Debentures at a repurchase price
in cash equal to 100% of the  principal  amount  thereof plus accrued and unpaid
interest, if any, to the date of repurchase in accordance with this Section 4.1.

     (b) Within 30 days following any Repurchase Event, the Company shall mail a
notice  to each  Holder  of the  Series  A  Convertible  Debentures  at its last
registered address with a copy to the Trustee stating:

          (1) that a Repurchase  Event has occurred and that such Holder has the
     right  to  require  the  Company  to  repurchase  such  Holder's  Series  A
     Convertible  Debentures at a repurchase  price in cash equal to 100% of the
     principal amount thereof plus accrued and unpaid  interest,  if any, to the
     date of repurchase (the "Repurchase Offer");

          (2) the  circumstances  and relevant facts  regarding such  Repurchase
     Event (including  information with respect to pro forma historical  income,
     cash flow and capitalization after giving effect to such Repurchase Event);


                                       5





          (3) the  repurchase  date (which  shall be not earlier than 30 days or
     later than 60 days from the date such  notice is mailed)  (the  "Repurchase
     Date");

          (4) that any Series A Convertible Debenture not tendered will continue
     to accrue interest;

          (5) that any  Series A  Convertible  Debenture  accepted  for  payment
     pursuant to the Repurchase  Offer shall cease to accrue  interest after the
     Repurchase Date;

          (6) that  Holders  electing to have a Series A  Convertible  Debenture
     purchased  pursuant to a Repurchase Offer will be required to surrender the
     Series A Convertible Debenture, with the form entitled "Option of Holder to
     Elect  Purchase"  on the  reverse  of the  Series A  Convertible  Debenture
     completed, to the Paying Agent at the address specified in the notice prior
     to the close of business on the Repurchase Date;

          (7) that  Holders will be entitled to withdraw  their  election if the
     Paying  Agent  receives,  not later than the close of business on the third
     Business Day (or such shorter period as may be required by applicable  law)
     preceding the Repurchase  Date, a facsimile  transmission or letter setting
     forth the name of the Holder,  the principal amount of Series A Convertible
     Debentures  the Holder  delivered for purchase,  and a statement  that such
     Holder  is  withdrawing  his  election  to have such  Series A  Convertible
     Debentures purchased; and

          (8) that  Holders  which  elect  to have  their  Series A  Convertible
     Debentures  purchased  only in part will be issued new Series A Convertible
     Debentures in a principal  amount equal to the  unpurchased  portion of the
     Series A Convertible Debenture surrendered.

     (c) On the Repurchase Date, the Company shall:

               (i)  accept  for  payment  Series  A  Convertible  Debentures  or
          portions thereof tendered pursuant to the Repurchase Offer;

               (ii) deposit by 10:00 a.m., New York City time,  with the Trustee
          money sufficient to pay the purchase price of all Series A Convertible
          Debentures or portions thereof so tendered; and

               (iii)  deliver or cause to be delivered  to the Trustee  Series A
          Convertible   Debentures  so  accepted 


                                       6





          together  with an  Officers'  Certificate  identifying  the  Series  A
          Convertible Debentures or portions thereof tendered to the Company.

     The Trustee shall  promptly mail to the Holders of the Series A Convertible
Debentures  so accepted  payment in an amount equal to the purchase  price,  and
promptly  authenticate  and make  available  for  delivery to such Holders a new
Series A Convertible  Debenture in a principal  amount equal to any  unpurchased
portion of the Series A  Convertible  Debenture  surrendered.  The Company  will
publicly  announce  the  results  of  the  Repurchase  Offer  on or as  soon  as
practicable after the Repurchase Date.

     The Company shall comply with all  applicable  tender offer rules under the
Exchange Act,  including,  without  limitation,  Rules 13e-4 and 14e-1 under the
Exchange Act, as then in effect with respect to any such Repurchase Offer.

     SECTION 4.2. LIMITATION ON ADDITIONAL TIERS OF JUNIOR SUBORDINATED DEBT.

     The  Company  will not incur or suffer to exist any Debt,  other  than Debt
evidenced by the Series A Convertible Debentures,  that is subordinated in right
of payment to any Senior Subordinated Debt unless such Debt, by its terms or the
terms of the  instrument  creating  or  evidencing  it, is pari passu  with,  or
subordinated in right of payment to, Series A Convertible Debentures.

                                  ARTICLE FIVE

                            CONVERSION OF DEBENTURES

     The Series A Convertible  Debentures  shall be  convertible  into shares of
Common Stock upon the following terms and conditions:

     SECTION 5.1. CONVERSION PRIVILEGE AND CONVERSION PRICE.

     Subject to and upon compliance with the provisions of this Article Five, at
the option of the Holder  thereof,  any Series A  Convertible  Debentures or any
portion of the principal amount thereof which is $1,000 or an integral  multiple
of $1,000 may be converted at the principal  amount thereof,  or of such portion
thereof,  into  fully  paid  and  nonassessable  shares  (calculated  as to each
conversion  to the nearest  1/100 of a 


                                       7





share)  of Common  Stock at the  conversion  price,  determined  as  hereinafter
provided,  in effect at the time of  conversion.  Such  conversion  right  shall
expire at the close of business on August 15, 2005. In case Series A Convertible
Debentures or a portion  thereof is called for redemption at the election of the
Company, such conversion right in respect of the Series A Convertible Debentures
shall expire at the close of business on the second  business day  preceding the
Redemption Date.

     The  price at  which  shares  of  Common  Stock  shall  be  delivered  upon
conversion (herein called the "conversion  price") shall be initially $54.00 per
share of Common  Stock.  The  conversion  price  shall be  adjusted  in  certain
instances as provided in this Article Five.

     SECTION 5.2. EXERCISE OF CONVERSION PRIVILEGE.

     In order to exercise the conversion  privilege,  the Holder of any Series A
Convertible  Debenture to be converted shall surrender such Series A Convertible
Debenture,  duly endorsed or assigned to the Company or in blank,  at any office
or agency of the Company  maintained for that purpose pursuant to Section 4.2 of
the Indenture,  accompanied by written notice of conversion in the form provided
on the Series A Convertible  Debenture (or such other notice as is acceptable to
the  Company) at such office or agency  that the Holder  elects to convert  such
Series A  Convertible  Debenture  or, if less than the entire  principal  amount
thereof  is to be  converted,  the  portion  thereof to be  converted.  Series A
Convertible  Debentures issued as Registered Global Securities will be converted
in accordance  with the standing  instructions  and procedures of the Depositary
and its participants. Series A Convertible Debentures surrendered for conversion
during the period from the close of business on any Regular  Record Date through
and including the next Interest Payment Date shall (except in the case of Series
A  Convertible  Debentures  or  portions  thereof  which  have been  called  for
redemption on a Redemption  Date  occurring on or before such  Interest  Payment
Date) be  accompanied by payment in New York Clearing House funds or other funds
acceptable  to the Company of an amount  equal to the  interest  payable on such
Interest Payment Date on the principal amount of Series A Convertible Debentures
being  surrendered for conversion.  Subject to the provisions of Section 2.13 of
the Indenture relating to the payment of defaulted interest by the Company,  the
interest  payment with respect to a Series A  Convertible  Debenture  called for
redemption on a Redemption  Date during the period from the close of business on
any Regular  Record Date through and including  the next  Interest  Payment Date
shall be payable on such  Interest  Payment  Date to the Holder of such Series A
Convertible  Debenture  at the close of  business  on such


                                       8





Regular Record Date  notwithstanding the conversion of such Series A Convertible
Debenture  after  such  Regular  Record  Date and on or  prior to such  Interest
Payment Date, and the Holder converting such Series A Convertible Debenture need
not include a payment of such  interest  payment  amount upon  surrender of such
Series A  Convertible  Debenture  for  conversion.  Except  as  provided  in the
preceding  sentence,  no payment or adjustment shall be made upon any conversion
on  account of any  interest  accrued  on the  Series A  Convertible  Debentures
surrendered  for  conversion  or on account of any dividends on the Common Stock
issued upon conversion.

     Series A  Convertible  Debentures  shall be deemed  to have been  converted
immediately  prior to the  close of  business  on the day of  surrender  of such
Series A Convertible  Debentures for conversion in accordance with the foregoing
provisions,  and at such  time  the  rights  of the  Holders  of such  Series  A
Convertible  Debentures  as  Holders  shall  cease,  and the  Person or  Persons
entitled to receive the Common Stock issuable upon  conversion  shall be treated
for all  purposes as the record  holder or holders of such Common  Stock at such
time. As promptly as practicable  on or after the  conversion  date, the Company
shall  issue and  shall  deliver  at such  office  or  agency a  certificate  or
certificates  for the  number  of full  shares  of Common  Stock  issuable  upon
conversion,  together  with  payment  in lieu of any  fraction  of a  share,  as
provided in Section 5.3.

     In the case of any Series A  Convertible  Debenture  which is  converted in
part only,  upon such conversion the Company shall execute and the Trustee shall
authenticate and deliver to the Holder thereof, at the expense of the Company, a
new  Series A  Convertible  Debenture  or  Series A  Convertible  Debentures  of
authorized  denominations in aggregate principal amount equal to the unconverted
portion of the principal amount of such Series A Convertible Debenture.

     SECTION 5.3. FRACTIONS OF SHARES.

     No  fractional  shares of Common Stock shall be issued upon  conversion  of
Series A Convertible Debentures. If more than one Series A Convertible Debenture
shall be surrendered  for conversion at one time by the same Holder,  the number
of full shares which shall be issuable upon conversion thereof shall be computed
on the  basis of the  aggregate  principal  amount of the  Series A  Convertible
Debentures  (or  specified  portions  thereof)  so  surrendered.  Instead of any
fractional  share of  Common  Stock  which  would  otherwise  be  issuable  upon
conversion  of any  Series A  Convertible  Debenture  or  Series  A  Convertible
Debentures  (or  specified  portions  thereof),  the  Company  shall  pay a cash
adjustment  in  respect of such  fraction


                                       9





in an amount equal to such fraction multiplied by the Closing Price per share of
Common Stock  (consistent with Section 5.4(h) below) at the close of business on
the day of conversion  (or, if such day is not a Trading Day, on the Trading Day
immediately preceding such day).

     SECTION 5.4. ADJUSTMENT OF CONVERSION PRICE.

     (a) In case the Company shall pay or make a dividend or other  distribution
in Common  Stock on any class of capital  stock of the Company,  the  conversion
price in effect at the opening of business on the day  following  the date fixed
for the determination of stockholders entitled to receive such dividend or other
distribution shall be reduced by multiplying such conversion price by a fraction
of which the numerator shall be the number of shares of Common Stock outstanding
at the  close of  business  on the date  fixed  for such  determination  and the
denominator  shall be the sum of such  number of shares and the total  number of
shares  constituting  such  dividend or other  distribution,  such  reduction to
become effective  immediately after the opening of business on the day following
the date fixed for such  determination.  For the purposes of this paragraph (a),
the number of shares of Common Stock at any time  outstanding  shall not include
shares held in the treasury of the Company but shall include shares  issuable in
respect of scrip  certificates  issued in lieu of  fractions of shares of Common
Stock.  The Company will not pay any dividend or make any distribution on shares
of Common Stock held in the treasury of the Company.

     (b) In case the Company  shall  issue  rights or warrants to all holders of
its Common Stock (not being  available on an equivalent  basis to Holders of the
Series A Convertible  Debentures upon  conversion)  entitling them (for a period
expiring within 45 days after the record date mentioned  below) to subscribe for
or  purchase  shares of Common  Stock at a price per share less than the Current
Market Price on the date fixed for the determination of stockholders entitled to
receive such rights or warrants,  the conversion  price in effect at the opening
of business on the day following the date fixed for such determination  shall be
reduced  by  multiplying  such  conversion  price by a  fraction  of  which  the
numerator shall be the number of shares of Common Stock outstanding at the close
of business on the date fixed for such  determination  plus the number of shares
of Common Stock which the aggregate of the offering price of the total number of
shares of Common Stock so offered for subscription or purchase would purchase at
such Current Market Price and the  denominator  shall be the number of shares of
Common  Stock  outstanding  at the close of  business on the date fixed for such
determination  plus  the  number  of  shares  of  Common  Stock so  offered  for
subscription or purchase,  such re-


                                       10





duction to become effective immediately after the opening of business on the day
following  the date  fixed  for such  determination.  For the  purposes  of this
paragraph  (b),  the  number of shares of Common  Stock at any time  outstanding
shall not include  shares held in the treasury of the Company but shall  include
shares issuable in respect of scrip certificates  issued in lieu of fractions of
shares of Common  Stock.  The  Company  will not issue any  rights,  options  or
warrants  in  respect  of shares of Common  Stock  held in the  treasury  of the
Company.  If at the end of the period  during  which such rights or warrants are
exercisable  not all such  rights or  warrants  shall have been  exercised,  the
conversion  price  shall be  immediately  readjusted  to what it would have been
based upon the number of additional shares of Common Stock actually issued.

     (c) In case  outstanding  shares of Common Stock shall be subdivided into a
greater number of shares of Common Stock,  the conversion price in effect at the
opening of business  on the day  following  the day upon which such  subdivision
becomes effective shall be proportionately  reduced,  and,  conversely,  in case
outstanding  shares of Common Stock shall each be combined into a smaller number
of shares of Common  Stock,  the  conversion  price in effect at the  opening of
business  on the day  following  the day upon  which  such  combination  becomes
effective shall be proportionately increased, such reduction or increase, as the
case may be, to become  effective  immediately  after the opening of business on
the day following the day upon which such  subdivision  or  combination  becomes
effective.

     (d) In case the Company shall, by dividend or otherwise,  distribute to all
holders of its Common Stock evidences of its  indebtedness,  shares of any class
of its capital stock or other assets  (including  securities,  but excluding any
cash,  rights or warrants  referred to in paragraph (b) of this Section 5.4, any
dividend or distribution  paid  exclusively in cash referred to in paragraph (e)
of this Section 5.4, any dividend or  distribution  referred to in paragraph (a)
of this  Section  5.4 and any  merger or  consolidation  to which  Section  5.11
applies),  the  conversion  price shall be adjusted so that the same shall equal
the price determined by multiplying the conversion  price in effect  immediately
prior to the  close of  business  on the date  fixed  for the  determination  of
stockholders  entitled to receive such  distribution  by a fraction of which the
numerator  shall  be the  Current  Market  Price  on the  date  fixed  for  such
determination  less the then fair market  value (as  determined  by the Board of
Directors,  whose  determination  shall be  conclusive  and described in a Board
Resolution  filed with the  Trustee)  of the  portion of the  assets,  shares or
evidences of indebtedness so distributed applicable to one share of Common Stock
and the  denominator  shall be such Current  Market  Price,  such  adjustment


                                       11





to become  effective  immediately  prior to the  opening of  business on the day
following  the date fixed for the  determination  of  stockholders  entitled  to
receive such distribution.

     (e) In case the Company shall, by dividend or otherwise,  distribute to all
holders of its Common Stock cash (excluding any cash that is distributed  upon a
merger  or  consolidation  to  which  Section  5.11  applies  or  as  part  of a
distribution  referred to in paragraph  (d) of this Section 5.4) in an aggregate
amount  that,  combined  together  with (1) the  aggregate  amount  of any other
distributions to all holders of its Common Stock made exclusively in cash within
the 12 months preceding the date of payment of such  distribution and in respect
of which no adjustment  pursuant to this  paragraph (e) has been made  excluding
cash distributed as part of a distribution  referred to in paragraph (d) of this
Section  5.4,  and (2) the  aggregate of any cash plus the fair market value (as
determined by the Board of Directors,  whose  determination  shall be conclusive
and described in a Board Resolution) of consideration  payable in respect of any
tender offer by the Company or any of its Subsidiaries for all or any portion of
the Common Stock concluded within the 12 months preceding the date of payment of
such  distribution  and in respect of which no adjustment  pursuant to paragraph
(f) of this Section 5.4 has been made, exceeds 15% of the product of the Current
Market  Price on the date for the  determination  of holders of shares of Common
Stock entitled to receive such distribution times the number of shares of Common
Stock  outstanding on such date, then, and in each such case,  immediately after
the close of business on such date for determination, the conversion price shall
be reduced so that the same shall equal the price  determined by multiplying the
conversion  price in effect  immediately  prior to the close of  business on the
date fixed for  determination  of the  stockholders  entitled  to  receive  such
distribution  by a fraction  (i) the  numerator  of which  shall be equal to the
Current  Market  Price on the date fixed for such  determination  less an amount
equal to the  quotient of (x) the excess of such  combined  amount over such 15%
and (y) the  number  of  shares of  Common  Stock  outstanding  on such date for
determination  and (ii) the  denominator  of which shall be equal to the Current
Market Price on such date for determination.

     (f) In case a tender offer made by the Company or any Subsidiary for all or
any portion of the Common  Stock shall  expire and such tender offer (as amended
upon the expiration thereof) shall require the payment to stockholders (based on
the acceptance (up to any maximum specified in the terms of the tender offer) of
Purchased Shares (as defined below)) of an aggregate consideration having a fair
market value (as determined by the Board of Directors, whose determination shall
be conclu-


                                       12





sive and described in a Board  Resolution)  that combined  together with (1) the
aggregate of the cash plus the fair market value (as  determined by the Board of
Directors,  whose  determination  shall be  conclusive  and described in a Board
Resolution), as of the expiration of such tender offer, of consideration payable
in respect of any other tender offer,  by the Company or any  Subsidiary for all
or any portion of the Common Stock expiring  within the 12 months  preceding the
expiration of such tender offer and in respect of which no  adjustment  pursuant
to this  paragraph  (f) has  been  made  and (2)  the  aggregate  amount  of any
distributions  to all holders of the Company's  Common Stock made exclusively in
cash within 12 months  preceding  the  expiration  of such  tender  offer and in
respect of which no adjustment pursuant to paragraph (e) of this Section 5.4 has
been made, exceeds 15% of the product of the Current Market Price as of the last
time (the  "Expiration  Time")  tenders  could have been made  pursuant  to such
tender  offer (as it may be amended)  times the number of shares of Common Stock
outstanding (including any tendered shares) on the Expiration Time, then, and in
each such case,  immediately  prior to the  opening of business on the day after
the date of the Expiration  Time, the conversion price shall be adjusted so that
the same shall equal the price determined by multiplying the conversion price in
effect immediately prior to close of business on the date of the Expiration Time
by a fraction  (i) the  numerator  of which shall be equal to (A) the product of
(I) the  current  market  price per share of the  Common  Stock  (determined  as
provided in paragraph  (h) of this  Section  5.4) on the date of the  Expiration
Time and (II) the number of shares of Common Stock  outstanding  (including  any
tendered  shares)  on the  Expiration  Time less (B) the amount of cash plus the
fair market value  (determined  as  aforesaid)  of the  aggregate  consideration
payable to stockholders  based on the acceptance (up to any maximum specified in
the terms of the tender offer) of Purchased Shares,  and (ii) the denominator of
which shall be equal to the product of (A) the current market price per share of
the Common Stock  (determined  as provided in paragraph (h) of this Section 5.4)
as of the  Expiration  Time  and  (B) the  number  of  shares  of  Common  Stock
outstanding  (including any tendered  shares) as of the Expiration Time less the
number of all shares  validly  tendered and not  withdrawn as of the  Expiration
Time (the shares deemed so accepted up to any such maximum, being referred to as
the "Purchased Shares").

     (g)  The   reclassification  of  Common  Stock  into  securities  including
securities  other than  Common  Stock  (other than any  reclassification  upon a
consolidation  or  merger  to which  Section  5.11  applies)  shall be deemed to
involve (i) a  distribution  of such  securities  other than Common Stock to all
holders of Common Stock (and the effective date of such  reclassifi-


                                       13





cation  shall  be  deemed  to be  "the  date  fixed  for  the  determination  of
stockholders entitled to receive such distribution" and the "date fixed for such
determination"  within the meaning of paragraph  (d) of this Section  5.4),  and
(ii) a subdivision or  combination,  as the case may be, of the number of shares
of Common Stock outstanding  immediately prior to such reclassification into the
number of shares of Common Stock  outstanding  immediately  thereafter  (and the
effective  date of such  reclassification  shall be  deemed  to be "the day upon
which  such  subdivision   becomes  effective"  or  "the  day  upon  which  such
combination becomes effective", as the case may be, and "the day upon which such
subdivision or combination  becomes  effective"  within the meaning of paragraph
(c) of this Section 5.4).

     (h) For the purpose of any computation  under  paragraphs (b), (d), (e) and
(f) of this Section 5.4, the current market price per share of Common Stock (the
"Current  Market  Price") on any date  shall be deemed to be the  average of the
daily Closing Prices for the 5 consecutive  Trading Days selected by the Company
commencing not more than 20 Trading Days before,  and ending not later than, the
earlier of the day in question  and the day before the "ex" date with respect to
the issuance or distribution requiring such computation. The "Closing Price" for
each Trading Day shall be the reported  last sale price  regular way or, in case
no such  reported  sale takes  place on such day,  the  average of the  reported
closing bid and asked  prices  regular way, in either case on the New York Stock
Exchange  or, if the Common  Stock is not listed or  admitted to trading on such
Exchange,  on the  principal  national  securities  exchange on which the Common
Stock is listed or  admitted to trading or, if not listed or admitted to trading
on any national securities  exchange,  on The Nasdaq National Market, or, if the
Common  Stock is not listed or  admitted to trading on any  national  securities
exchange or The Nasdaq National Market, the average of the closing bid and asked
prices  in the  over-the-counter  market  as  furnished  by any New  York  Stock
Exchange member firm selected from time to time by the Company for that purpose.
For purposes of this paragraph,  the term "'ex' date", when used with respect to
any  issuance  or  distribution,  shall  mean the first date on which the Common
Stock trades regular way on such exchange or in such market without the right to
receive such issuance or distribution.

     (i) No  adjustment  in the  conversion  price  shall be required to be made
until cumulative adjustments (plus any adjustments not previously made by reason
of this paragraph (i)) amount to at least 1% of the  conversion  price,  as last
adjusted;  provided,  however,  that any  adjustments  which by  reason  of this
paragraph  (i) are not  required  to be made shall be carried  forward and taken
into account in any subsequent adjust-


                                       14





ment.  All  calculations  under this  paragraph (i) shall be made to the nearest
cent.

     (j) In addition to those required by paragraphs (a), (b), (c), (d), (e) and
(f) of this Section 5.4, the Company from time to time may make such  reductions
in the conversion  price by any amount,  (i) to the extent  permitted by law for
any  period of at least 20 days,  in which case the  Company  shall give 15 days
notice of such  decrease and (ii) to such extent as it considers to be advisable
in order that any event treated for federal income tax purposes as a dividend of
stock or stock  rights  will not be taxable  to the  holders of shares of Common
Stock or,  if that is not  possible,  to  diminish  any  income  taxes  that are
otherwise  payable  because of such event.  The Company  shall have the power to
resolve any ambiguity or correct any error in this paragraph (j) and its actions
in so doing shall be final and conclusive.

     SECTION 5.5. NOTICE OF ADJUSTMENTS OF CONVERSION PRICE.

     Whenever the conversion price is adjusted as herein provided:

          (a) the  Company  shall  compute  the  adjusted  conversion  price  in
     accordance  with  Section 5.4 and shall  prepare an  Officer's  Certificate
     setting  forth the  adjusted  conversion  price and  showing in  reasonable
     detail the facts upon which such adjustment is based,  and such certificate
     shall  forthwith  be filed at each  office  or  agency  maintained  for the
     purpose  of  conversion  of Series A  Convertible  Debentures  pursuant  to
     Section 4.2 of the Indenture; and

          (b) a notice stating that the  conversion  price has been adjusted and
     setting forth the adjusted  conversion  price shall  forthwith be required,
     and as soon as  practicable  after it is  required,  such  notice  shall be
     mailed by the Company to all Holders of Series A Convertible  Debentures at
     their last addresses as they shall appear in the Security Register.

     SECTION 5.6. NOTICE OF CERTAIN CORPORATE ACTION.

     In case:

          (a) the Company shall  declare a dividend (or any other  distribution)
     on its  Common  Stock  payable  otherwise  than in cash  out of its  earned
     surplus; or


                                       15





          (b) the Company  shall  authorize  the  granting to the holders of its
     Common Stock of rights or warrants to subscribe  for or purchase any shares
     of capital stock of any class or of any other rights; or

          (c) of any  reclassification of the Common Stock of the Company (other
     than a  subdivision  or  combination  of its  outstanding  shares of Common
     Stock),  or of any  consolidation,  merger or share  exchange  to which the
     Company  is a party  and for  which  approval  of any  stockholders  of the
     Company is required, or of the sale or transfer of all or substantially all
     of the assets of the Company; or

          (d)  of the  voluntary  or  involuntary  dissolution,  liquidation  or
     winding up of the Company; or

          (e) the Company or any  Subsidiary  shall  commence a tender offer for
     all or a portion of the Company's  outstanding Common Stock (or shall amend
     any such tender offer);

then the Company shall cause to be filed at each office or agency maintained for
the purpose of conversion of Series A Convertible Debentures pursuant to Section
4.2 of the Indenture,  and shall cause to be mailed to all Holders at their last
addresses as they shall appear in the Security Register, at least 20 days (or 10
days in any case  specified in clause (a) or (b) above) prior to the  applicable
record or effective date hereinafter specified, a notice stating (x) the date on
which a record is to be taken for the  purpose of such  dividend,  distribution,
rights or warrants, or, if a record is not to be taken, the date as of which the
holders of Common Stock of record to be entitled to such dividend, distribution,
rights  or  warrants  are to be  determined,  or (y)  the  date  on  which  such
reclassification,   consolidation,   merger,  share  exchange,  sale,  transfer,
dissolution,  liquidation,  winding  up or tender  offer is  expected  to become
effective,  and the date or dates as of which it is  expected  that  holders  of
Common  Stock of record  shall be entitled to  exchange  their  shares of Common
Stock  for   securities,   cash  or  other   property   deliverable   upon  such
reclassification,   consolidation,   merger,  share  exchange,  sale,  transfer,
dissolution,  liquidation,  winding up or tender  offer.  Neither the failure to
give such notice nor any defect therein shall affect the legality or validity of
the proceedings  described in paragraphs (a) through (d) of this Section 5.6. If
at the time the Trustee shall not be the conversion agent, a copy of such notice
shall also forthwith be filed by the Company with the Trustee.


                                       16





     SECTION 5.7. COMPANY TO RESERVE COMMON STOCK.

     The  Company  shall at all  times  reserve  and keep  available  out of its
authorized  but  unissued  Common  Stock,  for  the  purpose  of  effecting  the
conversion  of Series A  Convertible  Debentures,  the full  number of shares of
Common Stock then  issuable  upon the  conversion  of all  outstanding  Series A
Convertible Debentures.

     SECTION 5.8. TAXES ON CONVERSIONS.

     The  Company  will pay any and all taxes  that may be payable in respect of
the  issue or  delivery  of shares of  Common  Stock on  conversion  of Series A
Convertible  Debentures  pursuant  hereto.  The Company shall not,  however,  be
required to pay any tax which may be payable in respect of any transfer involved
in the issue and delivery of shares of Common Stock in a name other than that of
the  Holder  of the  Series A  Convertible  Debenture  or  Series A  Convertible
Debentures to be converted,  and no such issue or delivery  shall be made unless
and until the Person requesting such issue has paid to the Company the amount of
any such tax, or has  established to the  satisfaction  of the Company that such
tax has been paid.

     SECTION 5.9. COVENANT AS TO COMMON STOCK.

     The Company  covenants  that all shares of Common Stock which may be issued
upon conversion of Series A Convertible Debentures will upon issue be fully paid
and  nonassessable  and, except as provided in Section 5.8, the Company will pay
all taxes, liens and charges with respect to the issue thereof.

     SECTION 5.10. CANCELLATION OF CONVERTED SERIES A CONVERTIBLE DEBENTURES.

     All Series A  Convertible  Debentures  delivered  for  conversion  shall be
delivered  to the Trustee to be canceled by or at the  direction of the Trustee,
which shall dispose of the same as provided in Section 2.11 of the Indenture.

     SECTION  5.11. PROVISIONS  IN CASE  OF  CONSOLIDATION,  MERGER  OR SALE OF
                    ASSETS.

     In case of any  consolidation of the Company with, or merger of the Company
into,  any other Person,  any merger of another  Person into the Company  (other
than a  merger  which  does  not  result  in any  reclassification,  conversion,
exchange or cancellation  of outstanding  shares of Common Stock of the Company)
or any  sale  or  transfer  of all or  substantially  all of the  assets  of the
Company,  the Person formed by such  consolida-


                                       17





tion or resulting  from such merger or which  acquires such assets,  as the case
may be,  shall  execute  and  deliver to the  Trustee a  supplemental  indenture
providing  that  the  Holder  of  each  Series  A  Convertible   Debenture  then
outstanding  shall have the right  thereafter,  during the period  such Series A
Convertible  Debenture  shall be  convertible  as  specified  in Section 5.1, to
convert  such Series A  Convertible  Debenture  only into the kind and amount of
securities, cash and other property receivable upon such consolidation,  merger,
sale or  transfer  by a holder of the  number  of shares of Common  Stock of the
Company into which such Series A Convertible Debenture might have been converted
immediately prior to such consolidation, merger, sale or transfer, assuming such
holder of Common  Stock of the  Company is not a Person  with which the  Company
consolidated  or into which the Company  merged or which merged into the Company
or to which such sale or  transfer  was made,  as the case may be  ("Constituent
Person"),  or an Affiliate of a Constituent  Person,  and failed to exercise his
rights of  election,  if any, as to the kind or amount of  securities,  cash and
other property  receivable  upon such  consolidation,  merger,  sale or transfer
(provided  that if the kind or amount  of  securities,  cash and other  property
receivable upon such consolidation, merger, sale or transfer is not the same for
each  share  of  Common  Stock of the  Company  held  immediately  prior to such
consolidation,  merger,  sale or transfer by others than a Constituent Person or
an Affiliate  thereof and in respect of which such rights of election  shall not
have been exercised ("non-electing share"), then for the purpose of this Article
Five the kind and amount of securities,  cash and other property receivable upon
such consolidation, merger, sale or transfer by each non-electing share shall be
deemed to be the kind and amount so  receivable  per share by a plurality of the
non-electing  shares. Such supplemental  indenture shall provide for adjustments
which,  for  events  subsequent  to the  effective  date  of  such  supplemental
indenture,  shall  be  as  nearly  equivalent  as  may  be  practicable  to  the
adjustments  provided for in this Article  Five.  The above  provisions  of this
Article Five shall similarly apply to successive consolidations,  mergers, sales
or transfers.

     SECTION 5.12. TRUSTEE'S DISCLAIMER.

     The Trustee has no duty to determine when an adjustment  under this Article
Five  should be made,  how it should be made or what it should be.  The  Trustee
makes no  representation as to the validity or value of any securities or assets
issued upon conversion of Series A Convertible Debentures. The Trustee shall not
be responsible for the Company's failure to comply with this Article Five.


                                       18





                                   ARTICLE SIX

                            MISCELLANEOUS PROVISIONS

     SECTION 6.1. RATIFICATION.

     The Indenture,  as supplemented by this First Supplemental Indenture, is in
all respects ratified and confirmed.  This First Supplemental Indenture shall be
deemed part of the  Indenture in the manner and to the extent herein and therein
provided.

     SECTION 6.2. COUNTERPARTS.

     This  First  Supplemental  Indenture  may  be  executed  in any  number  of
counterparts  each of which shall be an original;  but such  counterparts  shall
together constitute but one and the same instrument.





                                       19





     IN WITNESS WHEREOF,  the parties hereto have caused this First Supplemental
Indenture  to be duly  executed,  and  their  respective  corporate  seals to be
hereunto  affixed  and  attested,   on  the  date  or  dates  indicated  in  the
acknowledgments and as of the day and year first above written.

                                              THE AES CORPORATION

                                              By:
                                                 -------------------------------
                                                  Name:
                                                  Title:

Attest:

By:
   -------------------------------
    Name:
    Title:

                                              THE FIRST NATIONAL BANK OF
                                                CHICAGO, as Trustee

                                              By:
                                                 -------------------------------
                                                  Name:
                                                  Title:

Attest:

By:
   -------------------------------
    Name:
    Title:




                                       20





                                                                       EXHIBIT A

                (FORM OF FACE OF SERIES A CONVERTIBLE DEBENTURE)

     [IF THE  DEBENTURE IS TO BE A  REGISTERED  GLOBAL  SECURITY,  INSERT - This
Series A  Convertible  Debenture  is a  Registered  Global  Security  within the
meaning of the Indenture  hereinafter  referred to and is registered in the name
of a  Depositary  or a  nominee  of a  Depositary.  This  Series  A  Convertible
Debenture is exchangeable for Series A Convertible  Debentures registered in the
name of a person  other than the  Depositary  or its nominee only in the limited
circumstances  described  in the  Indenture,  and no  transfer  of this Series A
Convertible  Debenture  (other  than a  transfer  of this  Series A  Convertible
Debenture as a whole by the  Depositary  to a nominee of the  Depositary or by a
nominee  of  the  Depositary  to  the  Depositary  or  another  nominee  of  the
Depositary) may be registered except in limited circumstances.

     Unless this Series A  Convertible  Debenture is presented by an  authorized
representative  of The Depository Trust Company (55 Water Street,  New York, New
York) to the  issuer or its agent for  registration  of  transfer,  exchange  or
payment, and any Series A Convertible Debenture issued is registered in the name
of Cede & Co. or such other name as requested by an authorized representative of
The  Depository  Trust Company and any payment hereon is made to Cede & Co., ANY
TRANSFER,  PLEDGE OR OTHER USE  HEREOF  FOR  VALUE OR  OTHERWISE  BY A PERSON IS
WRONGFUL since the registered owner hereof, Cede Co., has an interest herein.]

No.                      $                  CUSIP NO.: 00130 HAN 5

            4.50% CONVERTIBLE JUNIOR SUBORDINATED DEBENTURE DUE 2005

                  THE AES CORPORATION promises to pay
                  to          or registered assigns the
                  principal sum of        Dollars on
                  August 15, 2005.

Interest  Payment  Dates:  February 15,  August 15 and at  maturity,  commencing
February 15, 1999.


                                      A-1





Record Dates:  February 1 or August 1, as the case may be, next  preceding  such
Interest Payment Date

                                                 By:____________________________
                                                       Authorized Signature

                                                 By:____________________________
                                                       Authorized Signature

Dated:

Certificate of Authentication

     This is one of the 4.50%  Convertible  Junior  Subordinated  Debentures due
2005 referred to in the within-mentioned Indenture.

                                                 The First National Bank of
                                                 Chicago, as Trustee

                                                 By:____________________________
                                                       Authorized Signatory




                                      A-2





               [FORM OF REVERSE OF SERIES A CONVERTIBLE DEBENTURE]

                               THE AES CORPORATION

            4.50% CONVERTIBLE JUNIOR SUBORDINATED DEBENTURE DUE 2005

     1. Interest.  THE AES CORPORATION,  a Delaware  corporation (the "Company,"
which  definition  shall  include any successor  thereto in accordance  with the
Indenture (as defined  below)),  promises to pay, until the principal  hereof is
paid or made available for payment,  interest on the principal  amount set forth
on the reverse side hereof at a rate of 4.50% per annum.  Interest on the Series
A Convertible  Debentures will accrue from and including the most recent date to
which  interest has been paid or, if no interest has been paid,  from August 10,
1998 through but excluding the date on which interest is paid. Interest shall be
payable in arrears on February 15, August 15 and at the stated maturity (each an
"Interest  Payment  Date"),  commencing  February  15,  1999.  Interest  will be
computed on the basis of a 360-day year of twelve 30-day months.

     2.  Method of  Payment.  The  Company  will pay  interest  on the  Series A
Convertible  Debentures  (except  defaulted  interest)  to the  Persons  who are
registered  Holders of Series A Convertible  Debentures at the close of business
on February 1 and August 1 next  preceding the Interest  Payment  Date.  Holders
must  surrender  Series A  Convertible  Debentures  to a Paying Agent to collect
principal  payments.  The  Company  will pay  principal,  premium,  if any,  and
interest  in money of the  United  States  that at the time of  payment is legal
tender  for  payment of public  and  private  debts.  At the  Company's  option,
interest may be paid by check mailed to the registered  address of the Holder of
this Series A Convertible Debenture.

     3.  Paying  Agent and  Registrar.  Initially,  The First  National  Bank of
Chicago (the "Trustee") will act as Paying Agent and Registrar.  The Company may
change any Paying Agent, Registrar or co-Registrar without notice.

     4. Indenture.  The Company issued the Series A Convertible Debentures under
an Indenture  dated as of August 10, 1998 between the Company and the Trustee as
supplemented  by the first  Supplemental  Indenture  dated as of August 10, 1998
between the Company and the Trustee (said  Indenture,  as so  supplemented,  the
"Indenture").  This  Series  A  Convertible  Deben-


                                      A-3





ture is one of an issue of Securities of the Company issued under the Indenture.
The terms of the Series A  Convertible  Debentures  include  those stated in the
Indenture  and  those  made  part of the  Indenture  by  reference  to the Trust
Indenture Act of 1939 (15 U.S. Code ss.ss. 77aaa-77bbbb) as amended from time to
time.  The Series A Convertible  Debentures  are subject to all such terms,  and
Series A Convertible Debentureholders are referred to the Indenture and such Act
for a statement of them. Capitalized terms used herein and not otherwise defined
have  the  meanings  set  forth  in the  Indenture.  The  Series  A  Convertible
Debentures  are general  unsecured  obligations of the Company  subordinated  in
right of payment to all Senior and Subordinated Debt of the Company,  limited in
aggregate principal amount to $150,000,000; provided, however, that in the event
the  Company  sells  any  Series  A  Convertible   Debentures  pursuant  to  the
over-allotment  option (the  "Over-Allotment  Option")  granted  pursuant to the
Underwriting  Agreement  dated August 4, 1998 between the Company,  Smith Barney
Inc., J.P.  Morgan  Securities  Inc.,  Donaldson,  Lufkin & Jenrette  Securities
Corporation,  Morgan Stanley & Co.  Incorporated,  PaineWebber  Incorporated and
C.E. Unterberg, Towbin, then the Trustee shall authenticate and deliver Series A
Convertible  Debentures for original issue in an aggregate  principal  amount of
$150,000,000  plus up to  $22,500,000  aggregate  principal  amount  of Series A
Convertible Debentures sold pursuant to the Over-Allotment Option. The Indenture
limits the ability of the Company and its Subsidiaries to incur additional tiers
of junior subordinated Debt.

     5. Optional Redemption.  The Series A Convertible Debentures are subject to
redemption,  at the Company's  option, in whole or from time to time in part, at
any time on or after  August  20,  2001,  upon not less than 30 nor more than 60
days'  notice  mailed to each holder of Series A  Convertible  Debentures  to be
redeemed at its address appearing in the Security Register and prior to maturity
at the following  Redemption  Prices  (expressed as percentages of the principal
amount) plus accrued  interest to the  Redemption  Date (subject to the right of
Holders of record on the relevant Regular Record Date to receive interest due or
on Interest Payment Date that is on or prior to the Redemption Date).

     If redeemed  during the  12-month  period  beginning  August 15 in the year
indicated, the Redemption Price shall be:


                                      A-4







                                                                     Redemption
      Year                                                             Price
      ----                                                             -----
                                                                       
      2001................................................            102.57%
      2002................................................            101.93%
      2003................................................            101.29%


and after August 15, 2004 at a Redemption  Price equal to 100% of the  principal
amount.

     6.  Mandatory  Redemption.  No sinking  fund is  provided  for the Series A
Convertible Debentures.

     7. Conversion.  Subject to the next two succeeding sentences, a Holder of a
Series A  Convertible  Debenture may convert it into Common Stock of the Company
at any time before the close of business on August 15, 2005; provided,  however,
that if a Series A Convertible  Debenture is called for  redemption,  the Holder
may convert it at any time before the close of business on the Redemption  Date.
A Series A Convertible Debenture in respect of which a Holder is exercising such
Holder's  option to require the Company to  purchase  such Series A  Convertible
Debenture  upon a  Repurchase  Event  may be  converted  only if the  notice  of
exercise is withdrawn in accordance with the terms of the Indenture.

     The initial  conversion price is $54.00 per share of Common Stock,  subject
to adjustment in certain  events  described in the  Indenture.  The Company will
deliver cash or a check in lieu of any fractional share of Common Stock.

     To convert a Series A Convertible  Debenture a Holder must (i) complete and
manually  sign the  conversion  notice on the back of the  Series A  Convertible
Debenture  or  complete  and  manually  sign a  facsimile  of such notice to the
Conversion  Agent (or the office or agency  referred  to in  Section  5.2 of the
First  Supplemental  Indenture) or, if  applicable,  complete and deliver to The
Depository  Trust Company  ("DTC" or the  "Depositary,"  which term includes any
successor thereto) the appropriate  instruction form for conversion  pursuant to
the  Depository's  book-entry  conversion  program,  (ii) surrender the Series A
Convertible  Debenture to a Conversion Agent by physical or book-entry  delivery
(which is not necessary in the case of conversion  pursuant to the  Depositary's
book-entry  conversion  program),  (iii) furnish  appropriate  endorsements  and
transfer  documents  if required  by the  Conversion  Agent,  the Company or the
Trustee  and (iv) pay any  transfer  or similar


                                      A-5





tax, if required. Book-entry delivery of a Series A Convertible Debenture to the
Conversion Agent may be made by any financial  institution that is a participant
in the Depositary;  conversion  through the Depositary's  book-entry  conversion
program is available for any Series A Convertible  Debenture  that is held in an
account maintained at the Depositary by any such participant.

     A Holder may convert a portion of a Series A  Convertible  Debenture if the
portion is $1,000 or an integral  multiple of $1,000.  No payment or  adjustment
will be made for  dividends  on the  Common  Stock,  except as  provided  in the
Indenture.

     The conversion  price will be subject to adjustment  upon the occurrence of
any  of  the   following   events:   (i)   the   subdivision,   combination   or
reclassification  of  outstanding  shares of Common  Stock;  (ii) the payment in
shares of Common  Stock of a dividend  or  distribution  on any class of capital
stock of the Company; (iii) the issuance of rights or warrants to all holders of
Common  Stock  entitling  them to acquire  shares of Common Stock at a price per
share less than the Current Market Price;  (iv) the  distribution to all holders
of Common Stock of shares of capital stock other than Common Stock, evidences of
indebtedness, cash and dividends, distributions, rights and warrants referred to
above);  (v) a distribution  consisting  exclusively of cash (excluding any cash
distributions  referred to in (iv)  above) to all holders of Common  Stock in an
aggregate amount that, together with (A) all other cash distributions (excluding
any cash  distributions  referred  to in (iv)  above)  made within the 12 months
preceding such  distribution and (B) any cash and the fair market value of other
consideration  payable  in  respect  of any  tender  offer by the  Company  or a
subsidiary of the Company for the Common Stock consummated  within the 12 months
preceding such distribution,  exceeds 15% of the Company's market capitalization
(determined as provided in the Indenture) on the date fixed for  determining the
stockholders  entitled  to such  distribution;  and (vi) the  consummation  of a
tender offer made by the Company or any subsidiary of the Company for the Common
Stock which involves an aggregate consideration that, together with (X) any cash
and other consideration payable in respect of any respect of any tender offer by
the Company or a subsidiary of the Company for the Common Stock consummated with
the 12  months  preceding  the  consummation  of such  tender  offer and (Y) the
aggregate  amount of all cash  distributions  (excluding any cash  distributions
referred  to in (iv)  above) to all  holders of the Common  Stock  within the 12


                                      A-6





months  preceding  the  consummation  of such tender  offer,  exceeds 15% of the
Company's  market capital  capitalization  at the date of  consummation  of such
tender offer. No adjustment of the conversion  price will be required to be made
until  cumulative  adjustments  amount to at least one percent of the conversion
price,  as last adjusted.  Any adjustment that would otherwise be required to be
made  shall  be  carried  forward  and  taken  into  account  in any  subsequent
adjustment.

     If the  Company  is a  party  to a  consolidation  or  merger  of the  type
specified in the Indenture,  or certain transfers of all or substantially all of
its assets to another Person, or in certain other circumstances described in the
Indenture  the right to convert a Series A  Convertible  Debenture  into  Common
Stock may be  changed  into a right to  convert  it into the kind and  amount of
securities,  cash or other  assets  that the Holder  would have  received if the
Holder had converted such Holder's Series A Convertible  Debentures  immediately
prior to such transaction.

     8. Offers to Purchase.  The  Indenture  provides  upon the  occurrence of a
Repurchase  Event and  subject to further  limitations  contained  therein,  the
Company shall make an offer to purchase the Series A  Convertible  Debentures in
accordance with the procedures set forth in the Indenture.

     9. Denominations,  Transfer,  Exchange. The Series A Convertible Debentures
are in registered form without coupons in  denominations  of $1,000 and integral
multiples  of $1,000.  A Holder may  transfer or exchange  Series A  Convertible
Debentures in accordance with the Indenture. The Registrar may require a Holder,
among other things, to furnish  appropriate  endorsements and transfer documents
and  to pay to it  any  taxes  and  fees  required  by law or  permitted  by the
Indenture.  The Registrar need not transfer or exchange any Series A Convertible
Debenture  or  portion  of  a  Series  A  Convertible   Debenture  selected  for
redemption,  or transfer or exchange any Series A Convertible  Debentures  for a
period of 15 days before selection of such Series A Convertible Debentures to be
redeemed.

     10. Persons Deemed Owners.  The registered holder of a Series A Convertible
Debenture may be treated as the owner of it for all purposes.

     11.  Unclaimed  Money.  If money for the payment of  principal  or interest
remains  unclaimed for two years, the Trustee or Paying Agent will pay the money
back to the Company


                                      A-7





at its written request.  After that,  Holders entitled to the money must look to
the Company for payment as general creditors unless an "abandoned  property" law
designates another Person.

     12. Amendment, Supplement, Waiver. The Company and the Trustee may, without
the consent of the holders of any outstanding  Series A Convertible  Debentures,
amend, waive or supplement the Indenture or the Series A Convertible  Debentures
for  certain  specified  purposes,   including,   among  other  things,   curing
ambiguities,  defects or  inconsistencies,  maintaining the qualification of the
Indenture  under the Trust Indenture Act of 1939 or making any other change that
does not  adversely  affect  the  rights of any  Holder.  Other  amendments  and
modifications  of the  Indenture or the Series A Convertible  Debentures  may be
made by the Company and the Trustee  with the consent of the Holders of not less
than a majority of the aggregate  principal  amount of the outstanding  Series A
Convertible  Debentures,  subject to certain exceptions requiring the consent of
the Holders of the particular Series A Convertible Debentures to be affected.

     13. Successor  Corporation.  When a successor  corporation  assumes all the
obligations of its predecessor under the Series A Convertible Debentures and the
Indenture  and the  transaction  complies  with the  terms of  Article  5 of the
Indenture, the predecessor corporation,  subject to certain exceptions,  will be
released from those obligations.

     14.  Defaults  and  Remedies.  Events  of  Default  are  set  forth  in the
Indenture.  Subject  to certain  limitations  in the  Indenture,  if an Event of
Default  (other than an Event of Default  specified in Section  6.1(d) or (e) of
the Indenture with respect to the Company)  occurs and is  continuing,  then the
holders of not less than 25% in aggregate  principal  amount of the  outstanding
Series A Convertible  Debentures may, or the Trustee may,  declare the principal
of,  premium,  if any,  plus  accrued  interest,  if any,  to be due and payable
immediately.  If an Event of Default  specified in Section  6.1(d) or (e) of the
Indenture with respect to the Company  occurs and is  continuing,  the principal
of,  premium,  if any, and accrued  interest on all of the Series A  Convertible
Debentures shall ipso facto become and be immediately due and payable subject to
the  prior  payment  in  full  of  Senior  and  Subordinated  Debt  without  any
declaration  or other act on the part of the  Trustee  or any  Holder.  Series A
Convertible  Debentureholders  may not  enforce  the  Indenture  or the Series A
Convertible  Debentures  except as  provided in the  Indenture.  The Trustee may
require indemnity 


                                      A-8





reasonably  satisfactory  to it before it enforces the Indenture or the Series A
Convertible Debentures. Subject to certain limitations, Holders of a majority in
principal  amount of the then  outstanding  Series A Convertible  Debentures may
direct the  Trustee  in its  exercise  of any trust or power.  The  Trustee  may
withhold from Series A  Convertible  Debentureholders  notice of any  continuing
default  (except a default in payment of  principal  or interest or a failure to
comply with  Article V of the  Indenture)  if it  determines  in good faith that
withholding  notice is in their  interests.  The Company  must furnish an annual
compliance certificate to the Trustee.

     15. Trustee  Dealings with Company.  The Trustee,  in its individual or any
other capacity,  may make loans to, accept  deposits from, and perform  services
for the Company or its  Affiliates,  and may otherwise  deal with the Company or
its Affiliates, as if it were not Trustee.

     16. No Recourse Against Others. A director, officer, employee,  stockholder
or  beneficiary,  as such,  of the Company  shall not have any liability for any
obligations  of the Company  under the Series A  Convertible  Debentures  or the
Indenture  or for any claim  based  on, in  respect  of or by  reason  of,  such
obligations  or their  creation.  Each Series A Convertible  Debentureholder  by
accepting  a  Series  A  Convertible  Debenture  waives  and  releases  all such
liability. The waiver and release are part of the consideration for the issue of
the Series A Convertible Debentures.

     17. Defeasance.  The Indenture contains  provisions (which provisions apply
to this Series A Convertible  Debenture)  for  defeasance at any time of (a) the
entire  indebtedness  of the  Company in respect  of this  Series A  Convertible
Debenture and (b) certain restrictive  covenants and related Defaults and Events
of Default,  in each case upon compliance by the Company with certain conditions
set forth therein.

     18. Authentication.  This Series A Convertible Debenture shall not be valid
until the Trustee signs the certificate of  authentication  on the other side of
this Series A Convertible Debenture.

     19.  Abbreviations.  Customary  abbreviations  may be used in the name of a
Series A Convertible Debentureholder or an assignee, such as: TEN COM (= tenants
in common),  TENANT (= tenants by the entireties),  JT TEN (= joint tenants with
right


                                      A-9





of survivorship and not as tenants in common),  CUST (= Custodian),  and U/G/M/A
(= Uniform Gifts to Minors Act).

     20. Subordination.  The Company's payment of principal of, premium, if any,
and interest on the Series A Convertible  Debentures is subordinated in right of
payment,  to  the  extent  and in  the  manner  provided  in  Article  11 of the
Indenture,  to the prior payment in full of the Senior and Subordinated  Debt of
the  Company.  Each  Holder  of the  Series  A  Convertible  Debentures,  by his
acceptance  hereof,  covenants and agrees that all payments of the principal of,
premium,  if any, and  interest on the Series A  Convertible  Debentures  by the
Company shall be subordinated in accordance with the provisions of Article 11 of
the  Indenture,  and  each  Holder  accepts  and  agrees  to be  bound  by  such
provisions.

     21.  GOVERNING  LAW. THE INDENTURE AND THIS SERIES A CONVERTIBLE  DEBENTURE
SHALL BE GOVERNED BY AND CONSTRUED IN  ACCORDANCE  WITH THE LAWS OF THE STATE OF
NEW YORK WITHOUT REGARD TO PRINCIPLES OF CONFLICTS OF LAW.

     The Company will furnish to any Series A Convertible  Debentureholder  upon
written request and without charge a copy of the Indenture. Requests may be made
to:

                  THE AES CORPORATION
                  1001 North 19th Street, Suite 2000
                  Arlington, Virginia  22209
                  Telephone: (703) 522-1315
                  Telecopy:  (703) 528-4510

                  Attention: General Counsel



                                      A-10





                                 ASSIGNMENT FORM

If you the holder want to assign this Series A  Convertible  Debenture,  fill in
the form below and have your signature guaranteed:

                  I  or  we  assign  and  transfer  this  Series  A  Convertible
Debenture to

- --------------------------------------------------------------------------------
(Insert assignee's social security or tax ID number)____________________________

- --------------------------------------------------------------------------------

- --------------------------------------------------------------------------------

- --------------------------------------------------------------------------------
(Print or type assignee's  name,  address and zip code) and irrevocably  appoint
agent to  transfer  this  Series A  Convertible  Debenture  on the  books of the
Company. The agent may substitute another to act for him.

Date:                               Your signature:
     ----------------------                        -----------------------------
                                                  (Sign  exactly  as  your  name
                                                  appears  on the other  side of
                                                  this   Series  A   Convertible
                                                  Debenture)

Signature Guarantee:____________________________________________________________

Signatures must be guaranteed by an "eligible guarantor institution" meeting the
requirements  of  the  Registrar,   which  requirements  include  membership  or
participation in the Securities  Transfer Agents Medallion  Program ("STAMP") or
such other "signature  guarantee  program" as may be determined by the Registrar
in addition  to, or in  substitution  for,  STAMP,  all in  accordance  with the
Securities Exchange Act of 1934, as amended.






                       OPTION OF HOLDER TO ELECT PURCHASE

     If you wish to have this Series A  Convertible  Debenture  purchased by the
Company upon the occurrence of a Repurchase Event, check the Box: [ ]

     If you  wish to have a  portion  of this  Series  A  Convertible  Debenture
purchased by the Company upon the  occurrence of a Repurchase  Event,  state the
amount: $

Date:__________            Your Signature:__________________

(Sign  exactly  as  your  name  appears  on the  other  side of  this  Series  A
Convertible Debenture)

     Signature Guarantee:_______________________

     Signatures  must  be  guaranteed  by an  "eligible  guarantor  institution"
meeting the requirements of the Registrar, which requirements include membership
or participation in the Securities  Transfer Agents Medallion  Program ("STAMP")
or  such  other  "signature  guarantee  program"  as  may be  determined  by the
Registrar in addition to, or in substitution  for, STAMP, all in accordance with
the Securities Exchange Act of 1934, as amended.









                                CONVERSION NOTICE

     The  undersigned  owner  of this  Series  A  Convertible  Debenture  hereby
irrevocably exercises the option to convert this Series A Convertible Debenture,
or the portion below  designated,  into Common Stock of THE AES CORPORATION,  in
accordance  with  the  terms  of the  Indenture  referred  to in this  Series  A
Convertible Debenture, and directs that the shares issuable and deliverable upon
conversion,  together with any check in payment for fractional shares, be issued
in the name of and  delivered to the  undersigned,  unless a different  name has
been indicated in the assignment  below.  If shares are to be issued in the name
of a person other than the  undersigned,  the undersigned  will pay all transfer
taxes payable with respect thereto.

Date:  __________, ____

in whole                       Portions of Series A Convertible  Debenture to be
                               converted ($1,000 or integral multiples thereof):
                               $


                               -------------------------------------------------
                               Signature (for conversion only)

                               Please  Print  or  Typewrite  Name  and  Address,
                               Including Zip Code, and Social  Security or Other
                               Identifying Number

                               -------------------------------------------------

                               -------------------------------------------------

                               -------------------------------------------------
                               Signature Guarantee:*____________________________

- ----------
*    Signature must be guaranteed by an "eligible Guarantor institution" that is
     a bank,  stockbroker,  savings and loan association or credit union meeting
     the  requirements  of the  Conversion  Agent,  which  requirements  include
     membership of  participation  in the Securities  Transfer Agents  Medallion
     Program  ("STAMP") or such other  "signature  guarantee  program" as may be
     determined by the Conversion Agent in addition to, or in substitution  for,
     STAMP,  all in  accordance  with the  Securities  Exchange Act of 1934,  as
     amended.