[GRAPHIC OF COPEC LETTERHEAD OMITTED]


Santiago, November 3, 2000


Naveed Ismail
The AES Corporation
c/o Jose Maria Eyzaguirre Baeza
Claro y Cia.
Apoquindo 3721, 13th Floor
Santiago, CHILE

Dear Sir:

You indicated that you are analyzing the possibility of effectuating (i) a
public offering in Chile to acquire 75% of the shares of the capital stock of
Gener S.A., as of September 30, 2000, excluding the shares represented by
ADSs, at a minimum unit price of the Chilean peso equivalent of US$ 0.235294118
per share (hereinafter referred to as the "OPA"); and (ii) an offer abroad for
the acquisition of all of the ADSs of Gener S.A., in exchange for shares of
your parent company.

In this respect, please note the following:

     1. Based upon your publicly announcing the OPA in Chile within the next 2
     days, Servicios de Combustibles Limitada (the owner to date of
     1,110,830,547 shares of Gener S.A.) and Compania de Petroleos de Chile S.A.
     (owner to date of 330,085 shares of Gener S.A.) are willing to sell under
     the OPA a minimum of 75% of their shares as indicated herein and, should
     the OPA process permit, any greater percentage up to 100% of their shares,
     for a minimum unit price of the Chilean peso equivalent of US$ 0.235294118
     per share.

     2. This commitment is conditioned on the event that no other interested
     party makes an offer to purchase the Gener S.A. shares that the sellers in
     good faith, based upon the opinion of their financial advisers, determine
     to be more advantageous. In the event that such an offer is made, the
     sellers shall immediately notify the contents of the offer and the name of
     the party making the offer, and deliver the available documents to the
     attorneys of Claro y Cia., to the attention of Jose Maria Eyzaguirre Baeza
     or, in his absence, Jose Maria




     Eyzaguirre Garcia de la Huerta. In the event that this offer, as indicated
     above, is considered to be more advantageous and the sellers are willing
     to accept it, they must then advise either of the attorneys named above,
     within no more than 5 days from the date of becoming aware of such offer,
     so that your company may match or better the offer within no more than 5
     days from the date of delivery of this latest communication. If your
     company does not respond or does not match or better the offer from the
     interested third party, the sellers shall be free to act as they wish,
     without any further engagement with you. In the event that the
     above-mentioned terms do not allow the purpose of this paragraph to be
     fulfilled, that is that the sellers may sell their shares under the most
     advantageous conditions and your company may match or better the last
     offer, said term shall be reduced as necessary in order to comply with said
     purpose, so that the term of 5 days for your company may be reduced to not
     less than 2 days.


     3. The sellers are considering using the authority conferred by article 58
     of the Law on Corporations to request Gener S.A. to convene a special
     shareholders' meeting to amend its bylaws so as to allow any one
     shareholder to hold more than 20% of the voting shares of Gener S.A.

     If you publicly announce the OPA in Chile within the next 2 days, the
     sellers agree to request that the Board of Directors of Gener S.A. convene
     a special shareholders' meeting in order to consider that the bylaws be
     amended so as to allow the OPA and the offering abroad to take place. In
     said meeting, the sellers agree to vote in favor of this proposal. Until
     November 15, 2000, your company may request that the sellers, enforce their
     right to convene a special shareholders' meeting of Gener S.A. If not so
     requested, the sellers may request that this meeting be convened and held
     when they deem appropriate.

     4. The sellers agree not to directly or indirectly: (a) request, initiate
     or encourage any proposal related to an alternative offer, nor to (b)
     participate in any discussions or negotiations, nor assist any person with
     regard to an alternative offer.

     5. If your company publicly announces the OPA in Chile within the term
     indicated above, you will be authorized to disclose that the sellers are
     willing to sell their shares in Gener S.A. under the terms and conditions
     indicated in this letter.

     6. The commitment of the sellers indicated in this letter shall be valid
     for a maximum of 120 days from today, or shall terminate earlier in the
     event that your company states that the OPA and the offering abroad were
     not successful, among other reasons, because the acquisition of a majority
     of the voting shares of Gener S.A. was not achieved.





                                       2





We trust that you will consider the terms of this letter in making your decision
as to whether or not to proceed with the OPA and remain,



                                    Very truly yours,

[signed] [signed]


for: Compania de Petroleos de Chile S.A.      for: Servicios de Combustibles
     Felipe Lamarca C. Jorge [illegible]           Limitada
                                                   Ricardo [illegible]
                                                   Ramiro  [illegible]

I concur and sign a copy of this letter
that shall remain in the possession
of the sellers. Santiago, November 3, 2000


[signed]

for:  The AES Corporation