Exhibit 10.b

THIS STOCK SALES AND SECURITY AGREEMENT IS EXECUTED BY AND BETWEEN LEADVILLE
MINING & MILLING CORPORATION, REPRESENTED IN THIS ACT BY ITS AGENT, MR. JACK
VEEDER EVERETT, HEREINAFTER REFERRED TO AS "LEADVILLE MINING", AND LEADVILLE
MINING & MILLING HOLDING CORPORATION, REPRESENTED IN THIS ACT BY ITS AGENT, MR.
ROGER AUSTIN NEWELL, HEREINAFTER REFERRED TO AS "LEADVILLE HOLDING", ON ONE
HAND; AND INMOBILIARIA RUBA, S.A. DE C.V., REPRESENTED BY MR. JESUS MIGUEL
SANDOVAL ARMENTA, IN THE CAPACITY OF GENERAL AGENT, HEREINAFTER REFERRED TO AS
"RUBA", and LUIS ALFONSO ANCHONDO CUILTY, BY THEIR OWN RIGHT, HEREINAFTER
REFERRED TO AS "ANCHONDO", ON THE OTHER HAND; BY VIRTUE OF THE FOLLOWING
RECITALS AND CLAUSES:

R E C I T A L S

I.- By "LEADVILLE MINING" and "LEADVILLE HOLDING":

a)    They are companies with nationality and corporate domicile in Nevada,
      United States of America, duly organized under the laws of said state and
      their agents have sufficient powers to execute this agreement as evidenced
      in the powers of attorney attached hereto as exhibit "1", and said powers
      have not been revoked, limited or modified in any manner.

b)    They are the lawful owners having full use and enjoyment of all property
      and corporate rights on 169,033,675 Common Nominative Shares, (hereinafter
      referred to as "THE STOCK") issued by the company called MINERA CHANATE,
      S.A. de C.V., which has been organized as a split company, resulting from
      the corporate break-up of the corporation called EXPLORACION Y MINERIA
      INDEPENDENCIA, S.A. DE C.V. ("the split company"), said stock being
      full-paid and subscribed and free of any lien, and it wishes to sell by
      means of this Agreement to "RUBA" y "ANCHONDO", pursuant to the
      proportions set forth herein.

c)    At present, the issuing company, Minera Chanate, S.A. de C.V., has a
      capital stock of $169,033,675 pesos, represented by 169,033,675 shares
      without expressing the face value thereof, and said capital stock is
      formed as follows:

<PAGE>

                                                                    Exhibit 10.b

CAPITAL STOCK

--------------------------------------------------------------------------------
                                 SHARES COVERED
--------------------------------------------------------------------------------
                                       FIXED          VARIABLE
CERTIFICATE    STOCKHOLDER            CAPITAL         CAPITAL        TOTAL
--------------------------------------------------------------------------------
1            LEADVILLE MINING &       4'849,999                      4'849,999
             MILLING
             CORPORATION
--------------------------------------------------------------------------------
2            LEADVILLE MINING &       1                              1
             MILLING HOLDING
             CORPORATION
--------------------------------------------------------------------------------
3            LEADVILLE MINING &                      163'617,768     163'617,768
             MILLING
             CORPORATION
--------------------------------------------------------------------------------
4            LEADVILLE MINING &                      565,907         565,907
             MILLING
             CORPORATION
--------------------------------------------------------------------------------

                    TOTAL SHARES OF CAPITAL STOCK 169,033,675

d)    That the stockholders of the split company Minera Chanate, S.A. de C.V.
      (hereinafter referred to as "THE ISSUER"), have agreed to sell 100% of the
      capital stock of said company distributed among Inmobiliaria Ruba, S.A. de
      C.V. and "ANCHONDO", subject to the security stipulated herein.

e)    That "THE STOCK" referred to in subsection c) above, constitute 100% of
      the capital social of "THE ISSUER", and presently is full-paid and
      subscribed and is sellable without any charge or lien, except for the
      security stipulated herein, since the aforementioned corporate break-up
      became legally effective in the month of December, 1997.

f)    That "LEADVILLE MINING" and "LEADVILLE HOLDING" do not have knowledge that
      "THE SPLIT COMPANY" has been in breach of contract with any bank or any
      type of creditor or stockholder or that any lawsuit of any kind has been
      filed against them, which may nullify or affect the validity of
      resolutions and the corporate break-up process and do not have


                                  Page 2 of 17
<PAGE>

                                                                    Exhibit 10.b

      knowledge of any type of complaints, claims or objections regarding said
      break-up throughout said process, under the terms of article 228 bis of
      the General Law of Business Corporations or different than the latter;
      therefore, the aforementioned corporate break-up has become fully
      effective for all legal purposes without any responsibility of any kind to
      the split company MINERA CHANATE, S.A. DE C.V., or its present
      stockholders other than the responsibilities and debts contained in the
      financial statements of the corporate break-up, its attached documents and
      notes.

g)    Up to this date, "THE ISSUER" and its stockholders have no present or
      contingent lawsuits, trials or economic claims; labor or fiscal
      liabilities; bank debts or debts to stockholders, creditors or
      contractors; or liabilities, debts or responsibilities of any other
      nature, other than the responsibilities and debts contained in the
      financial statements of the corporate break-up, its attached documents and
      notes, and other than the responsibilities and debts contained in the
      financial statements of MINERA CHANATE S.A. DE C.V., its attached
      documents and notes, as of March 30, 2002, attached hereto as exhibit "2".

h)    "THE ISSUER" has performed all of its operations in compliance with the
      applicable legislation.

II.- By "RUBA" and "ANCHONDO":

c)    JESUS MIGUEL SANDOVAL ARMENTA is the agent of "RUBA" with powers and
      rights to execute this Agreement, as evidenced in Public Instrument number
      1,210, volume 53, dated July 14, 1999, executed before Atty. Oscar
      Cayetano Becerra Tucker, Notary Public Number 28, presently commissioned
      in the Judicial District of Bravos, State of Chihuahua, duly filed with
      the Public Registry of Property and Commerce of Ciudad Juarez, Chihuahua,
      also stating, under oath of telling the truth, that said powers and rights
      have neither been revoked nor limited in any manner. An certified copy of
      said public instrument is attached hereto as exhibit "3".

d)    "RUBA" and "ANCHONDO" stated that they wish to acquire "THE STOCK",
      pursuant to the proportion hereinafter stated, such purchase and sell
      being subject to the security object of the fifth clause hereof.

III.- By the parties:

c)    They intend to execute this Stock Sales Agreement Subject to a Security
      whereby (i) "RUBA" acquires, in its favor, 169,033,674


                                  Page 3 of 17
<PAGE>

                                                                    Exhibit 10.b

      Shares, issued by Minera Chanate, S.A. de C.V., and presently owned by
      "LEADVILLE MINING" (hereinafter called ""THE STOCK" OF LEADVILLE MINING",
      previously described in recital I, subsection c), which is deemed
      reproduced herein as if it had been literally inserted, said shares being
      represented by stock certificates 1, 3 and 4, as set forth in said
      recital, and (ii) "ANCHONDO" acquires, in his favor, 1 Share, issued by
      Minera Chanate, S.A. de C.V., presently owned by "LEADVILLE HOLDING"
      (hereinafter "THE STOCK OF LEADVILLE HOLDING", previously described in
      recital I, subsection c), which is deemed reproduced herein as if it had
      been literally inserted, said stock being represented by stock certificate
      2 as set forth in said recital.

d)    They expressly acknowledge their legal capacity and rights with which they
      appear and represent they have no legal impediment or of any other nature
      that may affect the valid execution of this instrument; due to the
      foregoing, they formalize this Stock Sales and Security Agreement by
      virtue of the following:

C L A U S E S

FIRST.- "LEADVILLE MINING" hereby sells, without any reserve or limitation
whatsoever, "THE STOCK" OF LEADVILLE MINING" to "RUBA", and thereby "LEADVILLE
MINING" conveys to "RUBA" each and every property and corporate right derived
from holding said stock.

In turn, "RUBA" acquires "THE STOCK" OF LEADVILLE MINING", free of liens, except
for the security object of the fifth clause, under the terms and conditions set
forth herein.

"LEADVILLE HOLDING" hereby sells, without any reserve or limitation whatsoever,
"THE STOCK" OF LEADVILLE HOLDING" to "ANCHONDO", and thereby "LEADVILLE HOLDING"
conveys to "ANCHONDO" each and every property and corporate right derived from
holding said stock.

In turn, "ANCHONDO" acquires "THE STOCK OF LEADVILLE HOLDING", free of liens,
except for the security object of the fifth clause, under the terms and
conditions set forth herein.

SECOND.- The total price established for "THE STOCK" by virtue of this sales
amounts to US$2,131,616.36 (two million one hundred thirty one thousand six
hundred sixteen dollars and thirty six cents, legal tender of the


                                  Page 4 of 17
<PAGE>

                                                                    Exhibit 10.b

United States of America), which shall be paid by "RUBA" and "ANCHONDO"
proportionally to the number of shares acquired by each of them, to "LEADVILLE
MINING" and "LEADVILLE HOLDING", through the following installments:

(A) The first installment of US$639,484.91 (six hundred thirty nine thousand
four hundred eighty four dollars and ninety one cents, legal tender of the
United States of America) paid by "RUBA" upon the execution of this Agreement to
"LEADVILLE MINING", with check number 7227105, drawn by "RUBA" from its account
in Banco Internacional S.A.. "LEADVILLE MINING" delivers to "RUBA" a payment
receipt being as broad as permitted by the law for said first installment.

(B) A second installment of US$497,377.15 (four hundred ninety seven thousand
three hundred seventy seven dollars and fifteen cents, legal tender of the
United States of America), minus US$14,336.40 (fourteen thousand three hundred
thirty six dollars and forty cents, legal tender of the United States of
America), due to obligations due and payable of "THE ISSUER", that "RUBA" shall
pay to "LEADVILLE MINING" with a certified check on August 9 (nine), 2002 (two
thousand two), at the latest, plus common contractual interest at an annual rate
of 4.5% (four point five percent) on unpaid balances, payable at the domicile
located at Pedro Rosales de Leon 7548, Fraccionamiento Jardines del Seminario,
Ciudad Juarez, Chihuahua, 32500.

(C) A third installment of US$994,754.30 (nine hundred ninety four thousand
seven hundred fifty four dollars and thirty cents, legal tender of the United
States of America), that "RUBA" shall pay "LEADVILLE MINING" with a certified
check on December 9 (nine), 2002 (two thousand two), at the latest, plus common
contractual interest at an annual rate of 4.5% (four point five percent) on
unpaid balances, payable at the domicile located at Pedro Rosales de Leon 7548,
Fraccionamiento Jardines del Seminario, Ciudad Juarez, Chihuahua, 32500.

Any unpaid balance of the installments referred to in subsections (B) and (C) of
this clause shall generate interest at a rate of 7% (seven percent) throughout
the time said balance remains unpaid. Any late payment charges, if any, shall
also be paid at Pedro Rosales de Leon 7548, Fraccionamiento Jardines del
Seminario, Ciudad Juarez, Chihuahua, 32500.

"THE STOCK OF LEADVILLE HOLDING" shall be deemed paid by "RUBA" to "LEADVILLE
HOLDING" for account of "ANCHONDO" upon payment to "LEADVILLE MINING" of the
installment referred to in the preceding paragraph.


                                  Page 5 of 17
<PAGE>

                                                                    Exhibit 10.b

Prior to the date of execution of this Agreement (hereinafter occasionally
referred to as "the Date of Execution"), "LEADVILLE MINING" and "LEADVILLE
HOLDING" designated Humberto Garcia Borbon as their representative in Mexico,
under the terms of and for purposes of article 5, article 190, paragraph five,
and article 208 of the Income Tax Law, article 13 of the United States-Mexico
Double Taxation Treaty, rule 3.31.15 of the Miscellaneous Tax Resolution in
force and other applicable tax rules.

THIRD.- In this act, simultaneously upon payment of the sum referred to in
subsection (A) of the Second clause, "LEADVILLE MINING" delivers Stock
Certificates number 1, 3 and 4 to "RUBA", duly endorsed to transfer title in its
favor, with respect to 169,033,674 shares fully covered by said Certificates,
and "LEADVILLE HOLDING" delivers Stock Certificate number 2 to "ANCHONDO", duly
endorsed to transfer title in his favor, with respect to 1 share fully covered
by said Certificate, without any title reserve or limitation, except for the
security object of the fifth clause hereof. Furthermore, an inscription was made
in the Stock Certificate Register of MINERA CHANATE, S.A. DE C.V. for purposes
of registering "RUBA" and "ANCHONDO" as new stockholders of said Corporation,
substituting "LEADVILLE MINING" and "LEADVILLE HOLDING", respectively.

FOURTH.- The transfer of "THE STOCK" is effected by "LEADVILLE MINING" and by
"LEADVILLE HOLDING, without any encumbrance, lien, legal limitation regarding
ownership or rights, tax liability and/or any other type of liability on said
stock, except of the security object of the fifth clause hereof, and "LEADVILLE
MINING" and "LEADVILLE HOLDING" assume an obligation to indemnify "RUBA" in the
event of dispossession of or hidden defects in the object of this sale.

FIFTH.- In order to guarantee "LEADVILLE MINING" and "LEADVILLE HOLDING"
(collectively referred to in this clause as the "Pledgees") the payment of the
installments referred to in subsections (B) and (C) of the second clause hereof,
and the respective common contractual interests and late payment charges and any
other sum referred to in subsection (B) of this clause, "RUBA" and "ANCHONDO"
(collectively referred to in this clause as "the Pledgors") hereby create a
security (hereinafter referred to as "the Security") on "THE STOCK" in favor of
the Pledgees, subject to the following rules, in addition to any other rules
applicable under this Agreement:

(A) The Pledgors hereby create the Security in favor of the Pledgees by
endorsing Stock Certificates 1, 3 and 4 in favor of "LEADVILLE MINING", and
Stock Certificate 2 in favor of "LEADVILLE HOLDING" and delivering the aforesaid
original Certificates to the respective Pledgees on the Date of Execution.


                                  Page 6 of 17
<PAGE>

                                                                    Exhibit 10.b

(B) The Pledgors hereby create the Security in favor of the Pledgees,
respectively, for purposes of guaranteeing (i) the timely and full payment of
the installments referred to in subsections (B) and (C) of the second clause,
(ii) the timely and full payment of common contractual interests and late
payment charges set forth in the second clause, and (iii) the timely and full
reimbursement of any legal costs and fees, including reasonable attorneys fees
paid by the Pledgees so as to exercise any rights derived from the Security and
any other rights derived from this Agreement and any laws applicable hereto.

(C) The aforesaid Security is created in the first place and degree and shall
keep such preference and priority until all of the debts and liabilities thereby
secured are fully paid, under the terms of this clause set forth in the
preceding subsection, to the satisfaction of the Pledgees.

(D) Pursuant to what is set forth in article 338 of the General Law of Credit
Instruments and Operations, the Pledgees shall keep and maintain the
Certificates of "THE STOCK" pledged. In the event of the payment obligations
referred to in the second clause and subsection (B) of this clause are not
fulfilled, the Pledgees may exercise the rights inherent to "THE STOCK",
including the exclusive right to vote with "THE STOCK", at or outside a meeting,
in the proportion that corresponds to each Pledgee, (i) for the resolutions that
correspond to the special shareholders' meeting referred to in sections I, II,
III, V, VI, VII, VIII, IX, X, XI (except for the change of corporate name,
domicile and purposes, which may be determined by the vote of the Pledgors
pursuant to what is set forth in the following subsection) and XII of article
182 of the General Law of Business Corporations; (ii) any matter reserved to the
special meeting pursuant to the corporate bylaws of "THE ISSUER); (iii) the
resolutions that correspond to the regular meeting with respect to matters not
reserved to the vote of the Pledgors under the following subsection of this
clause; and (iv) the resolutions referred to in subsection (E) of this clause.

(E) Except for what is set forth in the second paragraph of this subsection, the
Pledgors shall have the exclusive rights to vote with "THE STOCK", at or outside
a meeting, in the proportion that corresponds to each of them, solely with
respect to (i) the resolutions of any special meeting which purpose is to change
the corporate purpose, domicile and name of "THE ISSUER"; (ii) the resolutions
of regular meetings which purpose is to appoint agents, a sole administrator or
board of directors and stockholders' representatives, with the restrictions
referred to in the following subsection, determine the wage and salary of the
sole administrator or board members and stockholders' representatives, and
increase the variable portion of the capital stock. During the Pledge Period,
the Pledgors and the board members or the sole administrator of "THE ISSUER"
appointed by the Pledgors shall not vote on


                                  Page 7 of 17
<PAGE>

                                                                    Exhibit 10.b

or order any distribution of dividends, or cause "THE ISSUER" to deliver or
distribute said dividends, not even as provisional dividends. Furthermore,
during the Pledge Period, the Pledgors shall not cause "THE ISSUER", its board
members or its sole administrator or any other person to deliver or distribute
any other kind of revenues or accounting entries classified or considered as
dividends by any applicable fiscal or business law.

(F) At or outside a special meeting, the Pledgees may amend the corporate bylaws
of "THE ISSUER" (i) to make them compatible with the provisions hereof; (ii) to
prohibit the use or utilization of any benefit, right or privilege of any kind
(hereinafter, collectively referred to as "the Benefits"), that "THE ISSUER" may
have on the Date of Execution, prior to the fulfillment of any and all
obligation and commitment of the Pledgors hereunder; (iii) to deprive the
administrative body of "THE ISSUER" and its executives, grantors of powers of
attorney, agents, commission agents and dependents of any powers or rights they
may have so as to cause or order "THE ISSUER", or any other person or entity, to
use and utilize the Benefits of "THE ISSUER" as of the Date of Execution, prior
to the fulfillment of any and all of the obligations and commitments of the
Pledgors hereunder; and (iv) to amend the corporate bylaws of "THE ISSUER" in
any other sense so as to ensure that "THE ISSUER" or any other person or entity
shall not use or utilize the Benefits prior to the fulfillment of any and all of
the obligations of the Pledgors hereunder, and to secure any payment rights and
prior claims relative to the payment conferred to the Pledgees under the
Security and this Agreement.

Any acts conducted and any contracts or agreements executed in violation of what
is set forth in this clause and the amendments to the bylaws resolved by the
vote of the Pledgees pursuant to this clause shall not be binding upon, or be
opposable or exercised to the prejudice of "THE ISSUER" or the Pledgees or any
of the board members, executives, grantors, agents, commission agents or
dependents of the Pledgees.

(G) On the Date of Execution, the Pledgees deliver the respective receipts
referred to in article 337 of the General Law of Credit Instruments and
Operations to the Pledgors, so that the Pledgors can vote with "THE STOCK" at or
outside any of the meetings referred to in subsection (E) of this clause, in the
proportion that may correspond to each Pledgor. During the Pledge Period, the
original certificates of "THE STOCK" shall be kept in deposit by Humberto Garcia
Borbon at the offices located at Torre Hermosillo, Boulevard Kino 309, floor 10,
Colonia Country Club, Hermosillo, Sonora 83010. The depositary shall make said
Certificates available to the Pledgees and their advisors and consultants as
many times as necessary; furthermore, once the Pledgors have fulfilled their
obligations hereunder, the depositary shall deliver said Certificates to the
Pledgors.


                                  Page 8 of 17
<PAGE>

                                                                    Exhibit 10.b

Within 15 calendar days following the date of execution hereof, the Pledgees
shall deliver to the Pledgors a copy of the acceptance of position and of the
receipt of the original Stock Certificates signed by Humberto Garcia Borbon.

(H) In the event the Pledgors fail to pay the Pledgees any of the installments
set forth in subsections (B) and (C) of the second clause hereof and the
respective common contractual interests or late payment charges on the dates set
forth in said second clause at the latest, and any other sums referred to in
subsection (B) of this clause, the Pledgees shall keep the amounts already paid
by the Pledgors to the Pledgees, without any responsibility to the Pledgees, in
addition to other rights and actions of the Pledgees derived from the Pledgors'
failure to comply, pursuant to this agreement and the law, without the Pledgors'
obligation exceeding the debts specified in subsections (B) and (C) of the
second clause hereof, including the common interests and late payment charges
and other sums referred to in subsection (B) of this clause.

The Pledgors shall have a maximum of 15 calendar days to cure any failure to
perform their obligations under to this Agreement or to begin to cure the same,
the latter at the satisfaction of the Pledgees, as of the date on which said
failure to perform had occurred. If the Pledgors fail to cure said failure to
perform or to begin to cure the same within said period of 15 calendar days, the
latter at the satisfaction of the Pledgees, then the Pledgees may enforce and
exercise any and all rights and actions conferred to them under this agreement
and the law with respect to said failure to perform, either separately or
cumulatively; however, the exercise of any of said rights and actions shall not
imply or operate as a waiver or abandonment of any other rights and actions.

(I) Any agreements or contracts (hereinafter, "The Agreements of the Pledge
Period") executed by "THE ISSUER" during the term (hereinafter referred to as
"the Pledge Period") elapsed from the Date of Execution to the date on which the
Pledgees recover "THE STOCK" (hereinafter, "the Date of Recovery") due to the
Pledgors' default or any other reason or circumstance, shall be governed by the
following rules:

(1) Any Agreements executed by "THE ISSUER" with any of its shareholders,
affiliates or subsidiaries (hereinafter, all of the shall be referred to as "the
Affiliates") during the Pledge Period, shall terminate automatically on the Date
of Recovery, that is, without requiring any additional notice, request, demand,
order or agreement, whether written or oral.

For purposes of this agreement, a "shareholder" of "THE ISSUER" refers to any
individual or corporation that holds any shares issued by "THE ISSUER", in any
proportion; an "affiliate" of "THE ISSUER" refers to any corporation


                                  Page 9 of 17
<PAGE>

                                                                    Exhibit 10.b

controlled or whose stock is owned, at least 51% (fifty one percent) thereof, by
any stockholder that controls or owns at least 51% (fifty one percent) of the
stock of "THE ISSUER"; and a "subsidiary" of "THE ISSUER" refers to any entity
controlled by "THE ISSUER" or whose stock is owned by "THE ISSUER", at least by
51% (fifty one percent).

(2) "RUBA" shall also acquire or assume automatically the rights and duties
acquired by "THE ISSUER" under the Agreements of the Pledge Period executed by
"THE ISSUER" with any individuals or corporations other than the Affiliates,
effective as of the Date of Recovery, that is, without requiring any additional
notice, request, demand, order or agreement, either oral or written.

(3) By virtue of the inscription of this agreement in the Public Registry of
Property and Commerce, this agreement shall be opposable and binding without any
limitation or restriction upon those who had executed any Agreements of the
Pledge Period with "THE ISSUER". In any case, without prejudice to what is set
forth in this paragraph and other parts of this agreement, the Pledgors shall
have the duty to obtain from the other parties to said Agreements any additional
consent or acquiescence that may be necessary so that the acquisition or
assumption of rights and duties object of paragraph (2) of this subsection (I)
becomes effective, without any obligation or responsibility to "THE ISSUER", the
Pledgees or the board members, executives, agents, commission agents and
dependents of the Pledgees.

(4) The stipulations contained in paragraphs (2) and (3) of this subsection (I)
shall also be applicable to any separate labor agreement or any collective
bargaining agreement executed in a given case by "THE ISSUER" during the Pledge
Period.

(5) "RUBA" shall (i) be jointly and severally liable without limitation for the
performance of any and all obligations contracted by "THE ISSUER" under the
Agreements of the Pledge Period, not only to and with respect to the other
parties to said Agreements, but also to and with respect to any authority and
private organization of any kind, (ii) hold the Pledgees free and clear of any
obligations and liabilities of any kind, resulting from or related to the
Agreements of the Pledge Period, (iii) indemnify the Pledgors for any damages
resulting from or related to the Agreements of the Pledge Period, without any
limitation, and (iv) reimburse the Pledgees any reasonable attorney's fees and
any legal costs and expenses paid by the Pledgees so as to defend themselves
against the other parties to any Agreements of the Pledge Period executed by
"THE ISSUER" or against any authorities and private organizations of any kind as
regards the Agreements of the Pledge Period. "ANCHONDO" shall not be jointly and
severally responsible for the foregoing, but only for the value of his stock.


                                 Page 10 of 17
<PAGE>

                                                                    Exhibit 10.b

(6) The Pledgees shall have the option to cause "THE ISSUER" to assume any
Agreement of the Pledge Period, in which case the Pledgors shall be relieved of
any obligation or responsibility resulting from said Agreement of the Pledge
Period, in the understanding that such assumption must be written, express and
separate so that it may be effective against or with respect to "THE ISSUER".

(J) The Pledgors shall have the right to the early payment to the Pledgees of
the installments foreseen in subsections (B) and (C) of the second clause
hereof, plus the respective contractual interests or late payment charges,
without any penalty or charge of any kind to the Pledgors.

(K) The Pledgors shall pay the debts hereunder to the Pledgees prior to the
payment of any debt that the Pledgors may have or assume with "THE ISSUER",
notwithstanding their nature and the date on which said debts are or had been
contracted with "THE ISSUER" and regardless of any payment stipulations agreed
by the Pledgors and "THE ISSUER".

(L) The Pledgees shall deliver the original stock certificate book of "THE
ISSUER" within 10 working days following the date on which the Pledgors had paid
the Pledgees the three installments set forth in the second clause, plus any
contractual interests and late payment charges, if any, and any other sum set
forth in subsection (B) of this clause. During the Pledge Period, the original
stock certificate book of "THE ISSUER" shall be deposited with Humberto Garcia
Borbon, at the offices located at Torre Hermosillo, Boulevard Kino 309, 10th
floor, Colonia Country Club, Hermosillo, Sonora, 83010. The depositary shall
make said stock register book available to the Pledgees, their advisors and
consultants as frequently as necessary.

Through Attorneys Rodrigo Tena Cruz, Liliana Janeth Jaquez Peinado and Enrique
Marcos Abularach, the Pledgees shall deliver the Pledgors a copy of the
acceptance of position and receipt of stock certificate book referred to in the
preceding paragraph, signed by Humberto Garcia Borbon, within 15 calendar days
following the date of execution hereof,

The Pledgors shall have the right to receive from the Pledgees a certified copy
of any entries in the stock certificate book, at the sole expense of the
Pledgors, within 10 working days following the date on which the Pledgors had
requested the same in writing.

(M) The Security shall be registered in the stock certificate book of "THE
ISSUER" within 5 working days immediately following the Date of Execution.


                                 Page 11 of 17
<PAGE>

                                                                    Exhibit 10.b

(N) This agreement shall be filed for registration with the Public Registry of
Property and Commerce of the new corporate domicile of "THE ISSUER" as
determined by the vote of the Pledgors, or the Public Registry of Property and
Commerce of Hermosillo, Sonora, if the Pledgors do not change the corporate
domicile of "THE ISSUER" from Hermosillo, Sonora to any other Municipality, at
the sole expense of the Pledgors, so that the provisions contained in this
clause and this agreement are effective with respect to any third party.

SIXTH.- "LEADVILLE MINING" and "LEADVILLE HOLDING" shall deliver the original
documents relative to "THE ISSUER" held by "LEADVILLE MINING", "LEADVILLE
HOLDING" and by any third party of which "LEADVILLE MINING" and "LEADVILLE
HOLDING" have knowledge and which can be legally delivered to the legal agent of
"RUBA", containing the accounting records of "THE ISSUER", the performance of
its tax liabilities, all of the original authorized copies of instruments
executed by said company, as well as the original and, in a given case, the
certificate of any and all of the company's books, except for the stock
certificate book, and other legal, administrative, accounting and financial
documents of the company, within 15 calendar days following the date of
execution hereof, at the domicile located at Boulevard Hidalgo number 64,
Colonia Centenario, Hermosillo, Sonora. JESUS MIGUEL SANDOVAL ARMENTA shall keep
in deposit, at the domicile located at Fracc. Jadines del Seminario, Cd. Juarez,
Chihuahua, Mexico, the records, instruments, authorized copies, books,
statements and other documents referred to in this paragraph, and he shall have
the obligation to return the same to "LEADVILLE MINING" and "LEADVILLE HOLDING"
within 10 calendar days following the date on which "LEADVILLE MINING" and
"LEADVILLE HOLDING" request the same for having recovered "THE STOCK" in
accordance herewith.

Any accounting records and books, tax return statements and accounting and tax
documentation supporting any entries and data contained in said books, records
and statements of "THE SPLIT COMPANY" shall be kept in deposit and custody of
the "SPLIT COMPANY", pursuant to the provisions of the applicable tax laws.
"RUBA" may have access to all of said books, records, statements and documents
under the terms of the applicable laws and regulations. As of the date of
execution hereof and as far as "LEADVILLE MINING" and "LEADVILLE HOLDING" have
been able to find, said books, records, statements and documents are kept in the
files of the offices of the "Sanchez-Mejorada, Velasco y Valencia" Firm, in
Mexico City, except for the documents lent by said firm to "LEADVILLE MINING",
which shall be returned by the latter to said firm upon the expiration of the
term for which said documents were lent.


                                 Page 12 of 17
<PAGE>

                                                                    Exhibit 10.b

"LEADVILLE MINING" and "LEADVILLE HOLDING" shall inform "THE ISSUER" and "RUBA"
of any claim or complaint filed against them, as well as the commencement,
processing and conclusion of all kinds of tax examinations by any authority.

SEVENTH. Subject to what is set forth in the second paragraph of this clause,
"LEADVILLE MINING" and "LEADVILLE HOLDING" agree to indemnify "RUBA", MINERA
CHANATE, S.A. DE C.V., "ANCHONDO", their employees, directors, representatives,
agents or their successors and assigns (the "Indemnified Parties"), at the
express written request of any of the Indemnified Parties, for any loss,
responsibility, damage, property damage claims or expenses (including reasonable
attorney's fees and reasonable legal costs) directly or indirectly derived from
(i) any representation by "LEADVILLE MINING" and "LEADVILLE HOLDING" contained
herein that are substantially false or substantially incorrect, and (ii) any
liability or claim that may arise with respect to the businesses, operations or
administration of "THE SPLIT COMPANY" and/or MINERA CHANATE, S.A. DE C.V. prior
to the date of execution of this Agreement (hereinafter, the "Damages").

"LEADVILLE MINING'S" and "LEADVILLE HOLDING'S" obligation to indemnify, as set
forth in the preceding paragraph with respect to the "SPLIT COMPANY" shall be
proportional to the assets, liabilities and capital stock transferred by the
"SPLIT COMPANY" to MINERA EL CHANATE, S.A. DE C.V., as a result of the corporate
break-up. "LEADVILLE MINING'S" and "LEADVILLE HOLDING'S" obligation to indemnify
referred to in the preceding paragraph with respect to MINERA EL CHANATE, S.A.
DE C.V. shall be joint and several without any limitation.

The obligation of "LEADVILLE MINING" and "LEADVILLE HOLDING" under the preceding
paragraph shall remain effective for a period equal to that set forth in the
law.

EIGHTH. By virtue of the execution of this agreement, "LEADVILLE MINING" and
"LEADVILLE HOLDING" shall be jointly and severally, fully and unconditionally
responsible for any type of contractual obligation or indemnification contracted
by the "SPLIT COMPANY" prior to the date on which the corporate break-up became
effective, for any sale of stock, concessions, construction projects or
contracts, transfer of contracts, permits and businesses of any kind, subject to
what is set forth in the second paragraph of this clause.

"LEADVILLE MINING'S" and "LEADVILLE HOLDING'S" obligation to indemnify set forth
in the preceding paragraph with respect to the "SPLIT COMPANY" shall be
proportional to the assets, liabilities and capital stock


                                 Page 13 of 17
<PAGE>

                                                                    Exhibit 10.b

transferred by the "SPLIT COMPANY" to MINERA EL CHANATE, S.A. DE C.V. as a
result of the corporate break-up.

At the request of "LEADVILLE MINING" and "LEADVILLE HOLDING" or the assignees or
purchasers of "THE ISSUER" (collectively referred to as "the Purchasers"),
"RUBA" shall cause "THE ISSUER" to sign and deliver to any of them all of the
documents that "LEADVILLE MINING", "LEADVILLE HOLDING" or the Purchasers, in
their sole discretion, may need with respect to any transfer of the mining
concessions, lots and other assets effected prior to the Date of Execution, or
that "LEADVILLE MINING" and "LEADVILLE HOLDING" or the Purchasers, in their sole
discretion, may require so as to file said transfers with the competent
registries. "RUBA" and "ANCHONDO" shall vote with their stock in "THE ISSUER" so
as to confer upon the parties designated by the Purchaser, any power and right
that said designated parties may require so as to carry out said registration
and comply with any government requirements related to said transfers.

NINTH. Notwithstanding this transaction has been structured as a stock sale,
"RUBA" and "ANCHONDO" acknowledge and agree that neither of them nor "THE
ISSUER" shall have the right to receive or benefit from the value-added tax that
the Mexican fiscal authorities shall reimburse or return to "THE ISSUER" on the
date of execution hereof. "RUBA" and "ANCHONDO" hereby grant Humberto Garcia
Borbon, Eduardo Robles Elias and Jose Joaquin Cabrera Ochoa, an irrevocable
special power of attorney that may be exercised jointly or separately, with
delegation powers, so that they process and obtain said value-added tax refund,
on behalf of "THE ISSUER", and forward the same to "THE ISSUER", so that the
latter, in turn, sends or transfers the same to "LEADVILLE MINING" or any party
designated by the latter, within 15 calendar days following the date on which
"THE ISSUER" receives said refund, in the understanding that the granting of
said power of attorney is a condition for the execution of this agreement.
"RUBA" and "ANCHONDO" agree to forward to "LEADVILLE MINING", within 5 (five)
working days following the date of receipt, the aforementioned value-added tax
that "RUBA" and/or "ANCHONDO" may receive directly from Mexican tax authorities
in a given case. In the event the aforementioned special agents require any
authorization, consent or special power of attorney other than that which is
conferred under this clause, "RUBA" and "ANCHONDO" hereby irrevocably authorize
Rodrigo Tena Cruz, Liliana Janeth Jaquez Peinado and Enrique Marcos Abularach to
grant, either jointly or separately, any such authorization, consent or special
power of attorney other than that which is conferred under this clause before a
notary public. "RUBA" and "ANCHONDO" shall cause "THE ISSUER" to directly
process the aforementioned tax refund in the event the required formalities must
be conducted before the tax authorities of the new corporate domicile of "THE
ISSUER".


                                 Page 14 of 17
<PAGE>

                                                                    Exhibit 10.b

The delivery of said value-added tax to "LEADVILLE MINING" by "RUBA" and
"ANCHONDO" shall be deemed as a surcharge of "THE STOCK". However, the clauses
of this agreement relative to contractual interest and late payment charges or
those relative to the Security shall not be applicable to said surcharge.

TENTH. Rodrigo Tena Cruz, Liliana Janeth Jaquez Peinado and Enrique Marcos
Abularach, jointly or separately, on behalf of "RUBA" and "ANCHONDO", and
Eduardo Robles Elias and Jose Joaquin Cabrera Ochoa, jointly or separately, on
behalf of "LEADVILLE MINING" and "LEADVILLE HOLDING", shall appear before a
notary public selected by "RUBA" so as to formally register this agreement
within 15 (fifteen) calendar days following the date of execution of this
private agreement. Any notary's fees and expenses, any registration charges of
the Public Registry of Property and Commerce incurred due to the formal
registration hereof and any fees and expenses incurred as a result of the
acknowledgement of the contents of this private agreement and the ratification
of signatures hereof shall be paid by "RUBA" at its sole expense.

ELEVENTH.- Neither "RUBA" nor "ANCHONDO" shall assign or transfer the rights and
duties hereunder, including the rights and duties derived from the Security, as
set forth in the fifth clause, and the legal rules applicable hereto without the
prior written express consent of "LEADVILLE MINING" and "LEADVILLE HOLDING".
Notwithstanding said consent is granted, "RUBA" and the assignee shall jointly
and severally responsible for the obligations assigned to the latter.

TWELFTH. Any and all notices under this agreement may be personally delivered or
sent by registered mail with acknowledgement of receipt to the domiciles of the
parties as indicated in the following clause or to any other domicile
subsequently indicated in writing by any of the parties.

THIRTEENTH. For purposes of this agreement, the addresses of the parties shall
be the following:

To LEADVILLE MINING & MILLING CORPORATION and to LEADVILLE MINING AND MILLING
HOLDING CORPORATION:

76 Beaver Street, Suite 500, New York, New York 10005 U.S.A.
Boulevard Hidalgo 64, Colonia Centenario, Hermosillo, Sonora, Mexico.

C.c.: Randy Hubbard, randy.hubbard@dgslaw

Attn.: Roger Austin Newell or Jack Veeder Everett or Atty. Eduardo Robles Elias

Fax: 001 (303) 526 5100
e-mail: ranewell@compuserve.com
        jfeverett@worldcom.att.net.com and
        Eduardo Robles Elias: erobles@hmo.megared.net.mx


                                 Page 15 of 17
<PAGE>

                                                                    Exhibit 10.b

To
Inmobiliaria Ruba, S.A. de C.V. and to Luis Anchondo Cuilty:

Prof. Pedro Rosales de Leon 7548
Fracc. Jardines del Seminario, C.P. 32500
Cd. Juarez, Chihuahua,
Mexico

Attn.: Direction General and/or Finance Direction
Fax: (656) 688-04-06
e-mail: luis.anchondo@ruba.com.mx
        conlegal@infosel.net.mx

TENTH.- "LEADVILLE MINING" and "LEADVILLE HOLDING" may disclose the execution of
this agreement and exhibit it to the Security Exchange Commission of the United
States of America, the similar commission in Canada and any other authorities of
said countries where this agreement must be exhibited under the law. "RUBA" and
"ANCHONDO" agree that the execution of this agreement and its contents shall be
kept confidential except if they have to disclose the same to the Mexican
competent authorities. This duty of confidentiality shall not be deemed violated
if "RUBA" and "ANCHONDO" must show this agreement to their advisors and
auditors.

ELEVENTH. In everything related to the interpretation and performance hereof or
any dispute that may arise with respect to this Agreement, both parties submit
to the jurisdiction and competence of the Courts of the city of Chihuahua,
Chihuahua, hereby expressly waiving any other jurisdiction that may be
applicable by reason of their present or future domiciles or any other
circumstance.


                                 Page 16 of 17
<PAGE>

                                                                    Exhibit 10.b

Once the foregoing had been read and its value and force had been duly explained
to the contracting parties, they signed it in the city of Ciudad Juarez, on the
30th day of the month of March, 2002, before two attesting witnesses.

Sr. Jack Veeder Everett                 Eng. Jesus Miguel Sandoval Armenta
Agent of Leadville Mining & Milling     Agent of Inmobiliaria Ruba, S.A. de C.V.
Corporation

Sr. Roger Austin Newell                 C.P. Luis Alfonso Anchondo Cuilty,
Agent of                                by his own right
Leadville Mining & Milling Holding
Corporation


                                 Page 17 of 17