LETTER OF INTENT
                                ----------------

PARTIES:          MINERA CONSTELACION (CONSTELACION)
                  AND MINERA MONTORO (MONTORO)


OBJECT:          "LOS VERDES" PROPERTY IN SONORA, MEXICO, COMPRISING 12 (TWELVE)
MINING  CONCESSIONS  (EXPLOITATION  AND  EXPLORATION),  AS PER LIST IN  ATTACHED
SCHEDULE  "A".  ALL  CONCESSIONS  SHALL BE DULY  UP-TO-DATE  ON ALL  OBLIGATIONS
THROUGH CONTRACT DATE.

TERMS:
                  1. AN EXCLUSIVE  120 DAY OPTION  PERIOD FOR THE DUE  DILIGENCE
         FOR A CONSIDERATION OF US$25,000; DURING THIS PERIOD MONTORO SHALL ALSO
         APPROACH THE FINANCING  REQUIREMENTS  OF THE PROJECT.  IF THE FINANCIAL
         INSTITUTIONS  REQUEST  ADDITIONAL  OR  CONFIRMATION   DRILLING  ON  THE
         PROPERTY,  THEN MONTORO SHALL REQUEST AND (CONSTELACION) SHALL GRANT AN
         EXTENSION OF AN ADDITIONAL 60 DAYS FOR THIS OPTION PERIOD.

                  2. AT THE END OF THE DUE  DILIGENCE-EXCLUSIVE  OPTION  PERIOD,
         MONTORO  MAY  EXERCISE  THE  OPTION FOR A TOTAL  PRICE OF US$5  MILLION
         DOLLARS TO BE PAID AS FOLLOWS: MONTORO WILL MADE A PAYMENT OF US$50,000
         AS PART OF THE  PURCHASE  PRICE  ON THE  DATE OF  FORMALIZATION  OF THE
         PURCHASE BY A PUBLIC NOTARY.

                  3. THEREAFTER, A PAYMENT OF US$100,000 WILL BE MADE AS PART OF
         THE  PURCHASE EVERY  TWELVE  MONTH PERIOD  UNTIL THE PROPERTY IS PLACED
         INTO COMMERCIAL PRODUCTION.

                  4.  ONCE  IN  PRODUCTION,  MONTORO  WILL  PAY TO  CONSTELACION
         US$1,000,000  EVERY  ANNIVERSARY FROM THE DATE OF PRODUCTION AS PART OF
         THE PURCHASE  PRICE.  HOWEVER THE FIRST MILLION  DOLLAR  PAYMENT AT THE
         FIRST YEAR AFTER PRODUCTION WILL BE REDUCED BY THE AMOUNTS ALREADY PAID
         AS PER THE PURCHASE PRICE. BUT IT CAN NOT BE LESS THAN  US$750,000.  IF
         DUE  TO  FORCE  MAJEURE  RELATED  TO  REASONABLE   CAUSE  SUCH  AS  THE
         SIGNIFICANT  DROP  IN  THE  METAL  PRICE,  MONTORO  SHALL  REQUEST  AND
         CONSTELACION  SHALL  GRANT A  NINETY  DAY  EXTENSION  OF ANY OF THE ONE
         MILLION DOLLAR PAYMENTS WITH AN INTEREST RATE AT PRIME RATE INTEREST.

                  5.  MONTORO  SHALL KEEP  CONSTELACION  INFORMED  BY  QUARTERLY
         PROGRESS REPORTS TO BE DELIVERED NO LATER THAN 45 DAYS AFTER THE END OF
         THE QUARTER. MONTORO SHALL WELCOME THE PRESENCE OF CONSTELACION-COMINCO
         REPRESENTATIVES  ON THE PROPERTY AT ANY TIME AS MUTUALLY AGREED UPON 10
         DAYS IN ADVANCE.

                  6.  MONTORO  SHALL KEEP ALL CONCESSIONS DULY CURRENT ON ALL OF
         THE LEGAL OBLIGATIONS FROM THE DATE OF THE SIGNATURE OF THE CONTRACT.






                  7. TRANSFER OF TITLE OF THE CONCESSIONS  SHALL BE EFFECTIVE AT
         THE MOMENT OF THE PAYMENT  MENTIONED IN THE SECTION  LABELED  "TERMS 2"
         FOR THE PURPOSE OF FACILITATING THE FINANCING OF THE PROJECT.  HOWEVER,
         MONTORO SHALL MAINTAIN ALL 12 CONCESSIONS  UNENCUMBERED AND FREE OF ANY
         LIEN AS A  GUARANTEE  TO  CONSTELACION  FOR EACH AND  EVERY  ONE OF THE
         PAYMENTS.

                  8. CONSTELACION  AGREES TO AN AREA OF INTEREST OF 2,500 METERS
         IN RADIUS FROM THE PORTAL OF THE "LOS VERDES" ADIT. WITHIN THIS AREA OF
         INTEREST,  CONSTELACION  GIVES  MONTORO THE  EXCLUSIVE  RIGHT TO OBTAIN
         MINING  CONCESSIONS.  IF MONTORO DOES NOT  EXERCISE  THE OPTION,  THESE
         CONCESSIONS SHALL ALSO BE RETURNED TO CONSTELACION.

                  9. IF MONTORO DOES NOT EXERCISE THE OPTION OR DOES NOT PAY ANY
         OF THE PAYMENTS OF THE FULL  PURCHASE  PRICE,  IT SHALL DELIVER ALL THE
         TECHNICAL  DATA  TO  CONSTELACION.   IN  THIS  CASE  CONSTELACION  WILL
         AUTOMATICALLY  ACQUIRE A 90 DAY OPTION TO BUY BACK THE  CONCESSIONS FOR
         AN AMOUNT OF US $100.


SIGNED ON THIS GUADALAJARA, JAL. DAY OF JUN 3 OF 1997.


MINERA CONSTELACION, S.A. DE C.V.                 MINERA MONTORO S.A. DE C.V.

         /S/                                               /S/
ING. OSCAR SANSORES BOLIVAR                       ING. JORGE E. ORDONEZ CORTES







                                    ANEXO "A"

                           PROYECTO LOS VERDES, SONORA

                                  LOTES MINEROS

CONCESION                                      NUMERO                           HECTAREAS
- ---------                                      ------                           ---------
                                                                                
BACANORA                                      T-168625                           238.9685

BACANORA TRES                                 T-194437                           12

LOS VERDES                                    T-168566                           14

BUENA VISTA                                   T-168569                           21

PIEDRAS AZULES                                T-178925                           132.7287

CONTINUACION BUENA VISTA                      T-168574                           30

LA NUEVA CRUZ DE SAN NICOLAS                  T-168573                           81

LA FRONTERA                                   T-168575                           15

DOS PICACHOS                                  T-168621                           31

LA BUFITA                                     T-193491                           10

LA VERDE                                      T-168576                           9

AMPLIACION LOS VERDES                         E-18087                            ---

TOTAL 12 LOTES MINEROS                                                           594.6972



PENDIENTE POR REDENUNCIAR-TERRENO ANTERIORMENTE AMPARADO POR:
BACANORA DOS E-16175