WARRANTY AGREEMENT

By this Warranty Agreement (the "Agreement"), executed and entered into in the
City of Sao Paulo, SP, Brazil, on the twentieth day of June, 2000, by and among
the parties below, on one side;

1. FiberCore, Inc., a company duly organized and validly existing under the laws
of the State of Nevada, United States of America, with head offices at 253,
Worcester Road, Charlton, MA ("FCI"), herein duly represented by its authorized
representative, or any other company or individual to be designated by it (FCI
and/or whichever entity so designated by FCI, hereinafter referred to as the
"Investor");


and, on the other side,


2. Algar S.A. - Empreendimentos e Participacoes, a company duly organized and
validly existing under the laws of the Federal Republic of Brazil, with head
offices in the City of Uberlandia, State of Minas Gerais, at Avenida Alexandrino
Garcia, 2689, Distrito Industrial, enrolled with CNPJ under No.
17.835.026/0001-52, herein represented by its duly authorized representative
(hereinafter referred to as "Algar"); and

3. Xtal Fibras Opticas S.A., a corporation duly organized and validly existing
under the laws of the Federal Republic of Brazil, with head offices in the City
of Uberlandia, State of Minas Gerais, at Avenida Alexandrino Garcia, 2689,
Distrito Industrial,. enrolled with CNPJ under No. 71.340.707/0001-95, herein
represented by its duly authorized representative (hereinafter referred to as
the "Xtal");


4. Mamore Participacoes S.A., a corporation duly organized and validly existing
under the laws of the Federal Republic of Brazil, Federal Republic of Brazil,
with head offices in the City of Uberlandia, State of Minas Gerais, at Avenida
Alexandrino Garcia, 2689, cj. 07, Sala A, Distrito Industrial, enrolled with
CNPJ under No. 03.509.491/0001-99, herein represented by its duly authorized
representative (hereinafter referred to as the "Company");

Whereas, the parties executed an Investment Agreement (the "Investment
Agreement") on June 1, 2000 for an investment in the Company by FCI;

Whereas, one of the conditions precedent for the execution of the Investment
Agreement was that FCI would provide to Algar a warranty in the amount
corresponding to the total value of debt that Algar had guaranteed on behalf of
Xtal Fibras Opticas S.A. ("Xtal");

Whereas, the Parties intend to legally formalize all the terms and conditions
which shall apply to the transactions described in the foregoing recitals;

Now, therefore, in view of the mutual promises, covenants and agreements
contained herein, and intending to be legally bound, the Parties have agreed to
execute this Agreement, pursuant to the following terms and conditions:

1.   FCI hereby expressly guarantees to Algar that FCI and Xtal will be
     responsible for the payment of the loan agreements ("Loans") and letters of
     credit ("Letters of Credit") of Xtal attached hereto as Annex A, that Algar
     has guaranteed for the benefit of Xtal.

2.   In the event that Xtal defaults on the payment of the Loans or the Letters
     of Credit attached in the Annex A ("Default") and Algar has to perform
     under its guarantees, FCI shall be liable to Algar for any amounts that
     Algar has disbursed in connection with such warranty.

     2.1.   In the event of a Default, Algar shall notify FCI before the payment
            of warranty and FCI shall have the right to pay the amounts due
            directly to the creditors, and FCI shall provide to Algar a document
            evidencing the release of the warranty.

     2.2.   In the event FCI is unable to pay directly to the creditors and
            Algar is obligated to pay the creditors, Algar shall notify FCI and
            present all the documents related to the disbursement effected by
            Algar in connection with the Default and FCI shall have 5 (five)
            business days to pay Algar for such disbursement, plus all costs
            incurred by Algar from the date of disbursement until the payment by
            FCI.

3.   FCI will use its best efforts to have Algar's guarantees listed in Annex A
     released, and to the extent such releases are not obtained by August 31,
     2000, then FCI shall pay to Algar or to any company indicated by Algar, all
     the costs incurred by Algar to maintain such guarantees until such time as
     such guarantees are released. Notwithstanding any provision herein, FCI
     shall cause Algar to be fully and completely released of all Algar's
     guarantees listed in Annex A on or before September 30, 2000. Algar shall
     be under no obligation to renew or extend any of such guarantees.

4.   Any notices, requests, claims, demands, instructions and other
     communications to be given hereunder to any party shall be in writing and
     delivered in person, sent by certified mail, postage prepaid, return
     receipt requested, or by facsimile transmission with a confirmed telephonic
     transmission answer back, to the following addresses (or at such other
     address or number as is given in writing by other party to the other
     pursuant hereto):

     If to Investor:      FiberCore, Inc.
                          P.O. BOX 180
                          253 Worcester Road
                          Charlton, MA  01507, U.S.A
                          Att: Dr. Mohd Aslami

     If to Algar:         Algar S.A. - Empreendimentos e Participacoes
                          Avenida Alexandrino Garcia, 2689
                          Distrito Industrial, Uberlandia
                          Att:  Nelson Cascelli Reis

     If to Xtal:          Xtal Fibras Opticas S.A.
                          Avenida Alexandrino Garcia, 2689 - Sala 8
                          Distrito Industrial, Uberlandia
                          Att:  Antonio Carlos de Campos

     If to Company:       Mamore Participacoes S.A.
                          Alexandrino Garcia, 2689, cj. 07, Sala A
                          Distrito Industrial, Uberlandia
                          Att:  Antonio Carlos de Campos

5.   This Agreement may be amended only upon the mutual written consent of the
     Parties hereto.


6.   This Agreement, including the Annexes and Exhibits hereto, constitutes the
     entire agreement between the Parties with respect to the subject matter
     hereof and supersedes all prior agreements and understandings between the
     parties. There are no representations, warranties, undertakings or
     agreements between the parties with respect to the subject matter of this
     Agreement except as set forth herein.

7.   None of the parties hereto may assign its rights, interests, obligations or
     liabilities under this Agreement or delegate its duties without the prior
     written consent of the other party. This Agreement and all of the
     provisions and Annexes hereof shall be binding upon and inure to the
     benefit of the parties hereto and their respective successors and permitted
     assigns.

8.   This Agreement shall be governed by, and construed in accordance with, the
     laws of Brazil. The courts of the City of Sao Paulo, State of Sao Paulo, to
     the personal jurisdiction of which each party hereto voluntarily submits,
     shall have exclusive jurisdiction over any dispute arising out of the
     construction, interpretation or enforcement of this Agreement.

In witness  whereof,  the  Parties  have  executed  this  Agreement  in 5 (five)
counterparts  of same  tenor and  content,  on the date and in the place  herein
before stated, in the presence of the two undersigned witnesses.




                                            -----------------------------------
                                            FiberCore, Inc.
                                            By: Mohd A. Aslami
                                            Title:   President - Chief Executive
                                                     Officer




                                            -----------------------------------
                                            Algar S.A.
                                            By:      Jose Mauro Leal Costa
                                            Title:   Chief Executive Officer
                                            By:      Nelson Cascelli Reis
                                            Title:   Attorney-in-fact




                                            -----------------------------------
                                            Xtal Fibras Opticas S.A.
                                            By:      Jose Mauro Leal Costa
                                            Title:   President
                                            By:      Antonio Carlos Campos
                                            Title:   Managing Director




                                            -----------------------------------
                                            Mamore Participacoes S.A.
                                            By:      Jose Mauro Leal Costa
                                            Title:   Attorney-in-fact
                                            By:      Nelson Cascelli Reis
                                            Title:   Attorney-in-fact



Witnesses:

1.
    ------------------------------------
    Name: Giseli Aparecida Perez Araujo
    RG: 16.978.964
    CPF: 074.393.068-13


2.
    ------------------------------------
    Name: Eliane Barbosa Mari
    RG: 8.690.203
    CPF: 762.429.948-87