Document:

<PAGE>

                                                                     EXHIBIT 4.6

                                PROMISSORY NOTE

$500,000                                                            June 7, 2000

FOR VALUE RECEIVED, AMERICAN TELESOURCE INTERNATIONAL, INC., a Delaware
corporation ("Maker") hereby promises to pay to the order of Alfonso Torres
Roqueni , his successors, assigns or any subsequent holder of this Note (the
"Lender") at his offices located at Blvd. M. Avila Camacho 184 16o. Piso, Col.
 ------
Lomas De San Isidro, C.P. 11620, Mexico , D.F. or at such other place as may be
designated in writing by Lender, in lawful money of the United States of America
in immediately available funds FIVE HUNDRED THOUSAND DOLLARS AND NO 00/100'S
($500,000.00) plus interest thereon at 6.62375 % (the "Interest Rate").

Reference is made to that Agreement dated as of June 7, 2000 between and among
Maker, Lender, Grupo Intelcom de Mexico, S.A. de C.V., and Telemarketing de
Mexico, S.A. de C.V. (the "Agreement"). Any term not otherwise defined in this
Note shall have the meaning given it in the Agreement.

Principal and accrued interest shall be payable on demand at any time five
Business Days following the Second Release, or the Simultaneous Release if the
case may be. Demand shall be made by written notice accompanied by the original
of this Note to Maker at its offices at 6000 Northwest Parkway, Suite 110, San
Antonio, Texas 78249. Maker may prepay this Note in part or in full at any time
without any fee or penalty.

Lender acknowledges that if a Termination of Escrow occurs pursuant to the
Agreement, this Note will be returned to Maker, and Maker shall have no
obligation to pay any sum remaining unpaid at that time. Maker's payment of
$100,000 upon a First Release pursuant to the Agreement will reduce the then
outstanding principal balance of this Note.

Interest shall accrue daily based on a 365 day year.

If Maker shall fail to pay within one (1) Business Day after demand any amount
payable under this Note, Maker shall pay to Lender additional interest on the
unpaid amount at the rate of eighteen (18%) percent (18%) per annum from the due
date until such overdue principal amount, interest or other unpaid amount is
paid in full ((both before and after judgment) whether or not any notice of
default has been delivered under the Agreement.

All amounts received for payment under this Note shall be applied first to
unpaid expenses due Lender under this Note, then to accrued but unpaid interest,
then to principal.

Notwithstanding any provision of this Note or the Agreement to the contrary, it
is the intent of the Lender and the Maker that the Lender shall never be
entitled to receive, collect, reserve or apply, as interest, any amount in
excess of the maximum rate of interest permitted to be charged by applicable
law, as amended or enacted, from time to time. In the event Lender ever
receives,
<PAGE>

collects, reserves or applies, as interest, any such excess, such amount which
would be excessive interest shall be deemed a partial prepayment of principal
and treated as such or, if the principal indebtedness and all other amounts due
are paid in full, any remaining excess funds shall immediately be paid to the
Maker and the Lender shall not be subject to any penalties provided by any laws
for contracting for, charging, reserving or receiving interest in excess of the
maximum lawful rate. In determining whether or not the interest paid or payable,
under any specific contingency, exceeds the highest lawful rate, the Maker and
the Lender shall, to the maximum extent permitted under applicable law amortize,
prorate, allocate, and spread, in equal parts, the total amount of interest
throughout the entire term of the indebtedness.

Maker hereby expressly waives demand, presentment, notice, protest, all legal
diligence in enforcing collection, and all other claims and defenses based on
any and all delays, extensions, renewals or other modifications of this Note or
any waivers of any term hereof or any failure to act on the part of Lender, and
hereby agrees that no such action, failure to act or failure to exercise any
right or remedy by Lender shall in any way affect or impair Maker's obligations.

THIS NOTE AND THE RIGHTS AND OBLIGATIONS OF MAKER AND LENDER SHALL BE GOVERNED
BY AND CONSTRUED AND ENFORCED IN ACCORDANCE WITH THE SUBSTANTIVE LAWS (BUT NOT
THE RULES GOVERNING CONFLICTS OF LAWS) OF THE STATE OF DELAWARE, U.S.A. The
parties agree that any action to enforce this Note may be brought only in a
state or federal court in Delaware, U.S.A., and Maker and Lender waive any
objection to the venue of any such suit. The parties irrevocably consent to the
service of process of any such courts in any such action or proceeding by the
mailing of copies thereof by registered or certified mail, postage prepaid,
return receipt requested, to such Maker at the address set forth in the
Agreement or to such other address as such Maker may have furnished to Lender in
writing, and agrees that such service shall become effective ten (10) days after
such mailing. However, nothing herein shall affect the right of Lender or any
Maker to serve process in any other manner permitted by law.

In the event this Note is placed in the hands of one or more attorneys for
collection, Maker agrees to pay all reasonable attorneys' fees and all court and
other out-of-pocket costs incurred by Lender, which shall be due on demand and
shall bear interest at the rate then payable hereunder from five (5) days after
such demand is made until paid.

If any provision of this Note should for any reason be invalid or unenforceable,
the remaining provisions hereof shall remain in full force and effect.

     This Note may not be changed, extended or terminated except in writing. No
waiver of any term or provision hereof shall be valid unless in writing signed
by Lender.
<PAGE>

         Executed as of the date first written above.

                                        AMERICAN TELESOURCE INTERNATIONAL,
                                        INC.

                                        ____________________________
                                        Arthur L. Smith
                                        Chief Executive Officer<PAGE>

                                                                     EXHIBIT 4.1
                                                                     -----------

               NOTE:  ATTACHED SCHEDULE FOR OMITTED INFORMATION

THE SECURITIES REPRESENTED BY THIS CERTIFICATE HAVE NOT BEEN REGISTERED UNDER
THE SECURITIES ACT OF 1933, AS AMENDED, OR THE SECURITIES LAWS OF ANY STATE, AND
MAY NOT BE SOLD, TRANSFERRED, PLEDGED OR OTHERWISE ENCUMBERED OR OTHERWISE
DISPOSED OF UNLESS REGISTERED OR AN EXEMPTION FROM REGISTRATION IS AVAILABLE.

No. __________                                                     $____________

                      DIAL-THRU INTERNATIONAL CORPORATION

                               CONVERTIBLE NOTE

     DIAL-THRU INTERNATIONAL CORPORATION, a Delaware corporation (together with
its successors, the "Corporation"), for value received hereby promises to pay
to:

                      ___________________________________

(the "Holder") and registered assigns, the principal sum of
____________________________ Dollars ($_________), on or before the earlier of
(a) February 4, 2001 or (b) the Corporation's consummation of a Qualified
Financing (as defined below) (the "Maturity Date"). This Convertible Note has
been issued pursuant to the terms of the Convertible Note and Warrant
Subscription Agreement delivered of even date herewith. No interest shall accrue
or be payable on the principal amount that may be outstanding from time to time
under this Convertible Note.

1.   CERTAIN DEFINITIONS.

     In addition to the defined terms included elsewhere herein, the following
terms as used herein shall have the following meanings:

     "Common Stock" means the common stock of the Corporation, par value $.001
per share.

     "Conversion Period" means the period commencing upon the ninety-first
(91st) day following the date hereof and ending upon the repayment in full of
this Convertible Note.

     "Conversion Price" shall mean $4.00 per share, as adjusted pursuant to
Section 4.3.

_______________________________________________________________________________
CONVERTIBLE NOTE - Page 1
<PAGE>

     "Qualified Financing" shall mean the Corporation's receipt of net proceeds
of no less than five million dollars ($5,000,000) as a result of the
consummation of any debt or equity financing by the Corporation, other than any
equipment financing or capital leases.

2.   PAYMENT TERMS.

     2.1. Convertible Note.  The principal balance of this Convertible
Note ("Convertible Note") shall be convertible at any time or from time to time,
in whole or in part, into Common Stock of the Corporation as set forth in
Article 4 below.

     2.2. Repayment of Note.

          (a)  The Corporation shall repay the remaining unpaid balance of this
     Convertible Note on the Maturity Date.

          (b)  The Corporation may voluntarily prepay all or any portion of this
     Convertible Note (in $1,000 increments) at any time prior to the
     commencement of the Conversion Period, and Holder shall not have any right
     to convert this Convertible Note with regard to the amounts so prepaid.

          (c)  The Corporation may voluntarily prepay all or any portion of this
     Convertible Note (in $1,000 increments) during the Conversion Period upon
     ten days prior notice to the Holder, whereupon the Holder shall have the
     right to convert this Convertible Note pursuant to Article 4 below.

     2.3. Method of Payment. The Corporation will pay all cash sums due on this
Convertible Note by wire transfer of immediately available funds to the Holder
of this Convertible Note in such coin or currency of the United States of
America as at the time of payment shall be legal tender for the payment of
public and private debts at the address specified for the Holder in Section 5.3,
or by such other method or at such other address as such Holder shall have from
time to time specified to the Corporation in writing for such purpose, without
the presentation or surrender of this Convertible Note.

     2.4. Additional Warrants. If this Convertible Note has not been repaid
within six months following the date of issuance, the Corporation will issue to
Holder warrants in the form attached hereto as Exhibit A to acquire an
                                               ---------
additional 125 shares of Common Stock at an exercise price of $2.75 per share
for each one thousand dollars ($1,000) principal amount outstanding (and not
previously converted) under this Convertible Note as of such date.

3.   REGISTRATION.

     3.1. Record Ownership. The Corporation shall maintain a register of the
Holder of this Convertible Note (the "Register") showing its name and address
and the serial number and principal amount of Convertible Note issued to or
transferred of record by it from time to time. The Register may be maintained in
electronic, magnetic or other computerized form. The Corporation may treat the
Person named as the Holder in the Register as the sole owner of this Convertible
Note. The Holder (as properly noted in the Register) is the Person exclusively
entitled to receive payments on this Convertible Note, receive notifications
with respect to this

_______________________________________________________________________________
CONVERTIBLE NOTE - Page 2
<PAGE>

Convertible Note, convert it into Common Stock and otherwise exercise all of the
rights and powers as the absolute owner hereof.

     3.2. Registration of Transfer. Transfers of this Convertible Note may be
registered on the Register. Transfers shall be registered when (i) this
Convertible Note is presented to the Corporation with a request to register the
transfer hereof; (ii) the Convertible Note is accompanied by a written
instrument of transfer in form reasonably satisfactory to the Corporation, duly
executed by the Holder thereof or his attorney duly authorized in writing; (iii)
the Corporation has received reasonable assurances that the endorsements are
genuine and effective; and (iv) the Corporation has received evidence reasonably
satisfactory to it that such transfer is rightful and in compliance with this
Convertible Note and all applicable laws, including state and federal securities
laws. When this Convertible Note is presented for transfer and duly transferred
hereunder, it shall be canceled and a new Convertible Note showing the name of
the transferee as the record holder thereof shall be issued in lieu hereof. When
this Convertible Note is presented to the Corporation with a reasonable request
to exchange it for an equal principal amount of Convertible Notes of other
denominations, the Corporation shall make such exchange and shall cancel this
Convertible Note and issue in lieu thereof Convertible Notes having a total
principal amount equal to the outstanding principal amount of this Convertible
Note in the denominations requested by the Holder.

     3.3. Worn and Lost Securities. If this Convertible Note becomes worn,
defaced or mutilated but is still substantially intact and recognizable, the
Corporation or its agent may issue a new Convertible Note in lieu hereof upon
its surrender bearing a number not contemporaneously outstanding. Where the
Holder claims that the Convertible Note has been lost, destroyed or wrongfully
taken, the Corporation shall issue a new Convertible Note in place of the
original Convertible Note bearing a number not contemporaneously outstanding if
the Holder so requests by written notice to the Corporation actually received by
the Corporation before it is notified that the Convertible Note has been
acquired by a bona fide purchaser and the Holder has delivered to the
Corporation an indemnity bond in such amount and issued by such surety as the
Corporation deems reasonably satisfactory together with an affidavit of the
Holder setting forth the facts concerning such loss, destruction or wrongful
taking and such other information in such form with such proof or verification
as the Corporation may reasonably request.

4.   CONVERSION AT THE OPTION OF THE HOLDER

     4.1. Optional Conversion. At the option of the Holder and at any time or
from time to time during the Conversion Period, all or any portion of the
outstanding principal balance of this Convertible Note may be converted into
that certain number of fully paid and nonassessable shares of Common Stock of
the Corporation as is determined by dividing such applicable balance of this
Convertible Note by the effective Conversion Price (the "Conversion Shares").

     4.2. Conversion Procedures.

          (a) The conversion of this Convertible Note will be deemed to have
     been effected as of the close of business on the date on which the Holder
     delivers a notice of conversion (including via telecopy) to the Corporation
     of the conversion of this

_______________________________________________________________________________
CONVERTIBLE NOTE - Page 3
<PAGE>

     Convertible Note (the "Conversion Date"). Any such notice must specify what
     portion of the outstanding principal balance of this Convertible Note is to
     be converted (the "Conversion Amount"). All Conversion Amounts must be in
     $1,000 increments.

          (b)  Within five Business Days of the Conversion Date, the Holder
     shall surrender this Convertible Note at the principal office of the
     Corporation.

          (c)  As soon as possible after a conversion has been effected (but in
     any event within five Business Days), the Corporation will deliver to the
     converting Holder a certificate or certificates representing the number of
     the Conversion Shares in such name or names and such denomination or
     denominations as the converting Holder has specified (the "Certificate
     Delivery"). If the Conversion Amount is less than the entire outstanding
     principal balance as of the Conversion Date, then the Corporation will also
     deliver to the converting Holder a new Convertible Note in the principal
     amount of any such remaining balance.

          (d)  On the Conversion Date, the rights of the Holder of this
     Convertible Note to receive payment of the Conversion Amount will cease and
     the Person or Persons in whose name or names any certificate or
     certificates for Conversion Shares are to be issued upon such conversion
     will be deemed to have become the holder or holders of record of the shares
     of Common Stock represented thereby.

          (e)  The issuance of certificates for the Conversion Shares will be
     made without charge to the Holder for any issuance tax in respect thereof
     or other cost incurred by the Corporation in connection with such
     conversion and the related issuance of shares of Common Stock. Upon
     conversion of this Convertible Note, the Corporation will take all such
     actions as are necessary in order to insure that the Common Stock issuable
     with respect to such conversion will be validly issued, fully paid and
     nonassessable.

          (f)  If any fractional interest in a share of Common Stock would,
     except for the provisions of this subparagraph (f), be deliverable upon any
     conversion of this Convertible Note, the Corporation, in lieu of delivering
     the fractional share therefor, will pay an amount to the Holder thereof
     equal to the fair market value of such fractional interest as of the date
     of conversion.

     4.3. Adjustments to Conversion Price. Upon the occurrence of any of the
following events, the following adjustments to the Conversion Price shall be
made:

          (a)  If the number of outstanding shares of Common Stock of the
     Company shall be increased by way of a stock dividend, stock split,
     recapitalization or similar means, the Conversion Price shall be adjusted
     by multiplying the Conversion Price in effect immediately prior to such
     stock increase by a fraction, the numerator of which shall be the number of
     shares of Common Stock outstanding immediately prior to such increase, and
     the denominator of which shall be the number of shares of Common Stock
     outstanding immediately following such increase.

          (b)  If the number of outstanding shares of Common Stock shall be
     reduced by a recapitalization, reverse stock split or otherwise, the
     Conversion Price shall be adjusted

_______________________________________________________________________________
CONVERTIBLE NOTE - Page 4
<PAGE>

     by multiplying the Conversion Price in effect immediately prior to such
     stock reduction by a fraction, the numerator of which shall be the number
     of shares of Common Stock outstanding immediately prior to such reduction,
     and the denominator of which shall be the number of shares of Common Stock
     outstanding immediately following such reduction.

          (c)  If the Corporation shall consolidate with, or merge into, another
     corporation, the Holder of this Convertible Note will thereafter receive,
     upon the conversion thereof, on equivalent terms of the Convertible Note,
     the securities or property to which the Holder of the number of shares of
     Common Stock then deliverable upon the conversion of this Convertible Note
     would have been entitled upon such consolidation or merger ("Other
     Securities"), and the Corporation shall take such steps in connection with
     such consolidation or merger as may be necessary to assure that the
     provisions hereof shall thereafter be applicable, as nearly as reasonably
     may be, in relation to any securities or property thereafter deliverable
     upon the conversion of this Convertible Note.

5.   MISCELLANEOUS.

     5.1. Powers and Remedies Cumulative. No right or remedy herein conferred
upon or reserved to the Holder is intended to be exclusive of any other right or
remedy, and every right and remedy shall, to the extent permitted by law, be
cumulative and in addition to every other right and remedy given hereunder or
now or hereafter existing at law or in equity or otherwise. The assertion or
employment of any right or remedy hereunder, or otherwise, shall not prevent the
concurrent assertion or employment of any other appropriate right or remedy.
Every power and remedy given by this Convertible Note or by law may be exercised
from time to time, and as often as shall be deemed expedient, by the Holder.

     5.2. Modification of Convertible Note. This Convertible Note may be
modified with the written consent of the Holder and the Corporation.

     5.3. Notices. Any notice required to be given under this Convertible Note
shall be deemed to have been given when written notice, addressed as hereafter
provided, is delivered by hand or is deposited in the United States mail,
postage prepaid, certified mail, return receipt requested at the addresses
specified below:

          (a)  If to the Corporation:

               Dial-Thru International Corporation
               8100 Jetstar Drive, Suite 100
               Irving, Texas  75083

          (b)  If to the Holder:

               ______________________
               ______________________
               ______________________

_______________________________________________________________________________
CONVERTIBLE NOTE - Page 5
<PAGE>

The address of either the Corporation or the Holder may be changed upon giving
notice in the manner specified above.

     5.4. Successors. All agreements of the Corporation and the Holder in this
Convertible Note shall bind their successors.

     5.5. Severability. In case any provision in this Convertible Note shall be
invalid, illegal or unenforceable, the validity, legality and enforceability of
the remaining provisions shall not in any way be affected or impaired thereby,
and the Holder shall have no claim therefor against any party hereto.

     5.6. Miscellaneous.

          (a)  This Convertible Note shall be deemed to be a contract made under
     the laws of the State of Texas and for all purposes shall be governed by
     and construed in accordance with the laws of said State without regard to
     the body of law controlling conflicts of law.

          (b)  The Holder by acceptance of this Convertible Note agrees to be
     bound by the provisions of this Convertible Note which are expressly
     binding on such Holder.

          (c)  If either the Corporation or the Holder commences any legal
     proceeding to collect upon or enforce the terms of this Convertible Note,
     the prevailing party shall be entitled to recover, in addition to any
     damages, its reasonable attorneys' fees and costs incurred in connection
     with enforcing the terms of this Convertible Note.

     IN WITNESS WHEREOF, the Corporation has caused this instrument to be duly
executed.

Dated: February 4, 2000

                            DIAL-THRU INTERNATIONAL CORPORATION

                            By: _______________________________
                                       Roger D. Bryant
                                       Chairman

_______________________________________________________________________________
CONVERTIBLE NOTE - Page 6
<PAGE>

                                   EXHIBIT A

                          Form of Contingent Warrant
                          --------------------------

THE SECURITIES REPRESENTED BY THIS CERTIFICATE HAVE NOT BEEN REGISTERED UNDER
THE SECURITIES ACT OF 1933, AS AMENDED, OR THE SECURITIES LAWS OF ANY STATE, AND
MAY NOT BE SOLD, TRANSFERRED, PLEDGED OR OTHERWISE ENCUMBERED OR OTHERWISE
DISPOSED OF UNLESS REGISTERED OR AN EXEMPTION FROM REGISTRATION IS AVAILABLE.

                      Dial-Thru International Corporation

                         COMMON STOCK PURCHASE WARRANT

                                                        DATED:  August ___, 2000

<TABLE>
<CAPTION>
----------------------------------------------------------------------------------------------
<S>                                <C>                       <C>
Number of Common Shares:           ______                    Holder: ___________________
Purchase Price:                    $2.75 per share                   ___________________
Expiration Date:                   August __, 2005           ___________________________
                                                                     ___________________

      For identification only. The governing terms of this Warrant are set forth below.
----------------------------------------------------------------------------------------------
</TABLE>

     Dial-Thru International Corporation, a Delaware corporation (the
"Company"), hereby certifies that, for value received, _________________ (the
"Holder"), is entitled, subject to the terms set forth below, to purchase from
the Company at any time or from time to time prior to August __, 2005 (the
"Exercise Period"), at the Purchase Price hereinafter set forth, _____
____________ (_______) fully paid and nonassessable shares of Common Stock (as
hereinafter defined) of the Company. The number and character of such shares of
Common Stock and the Purchase Price are subject to adjustment as provided
herein. This Warrant has been issued pursuant to the terms of the Convertible
Note and Warrant Subscription Agreement and a Convertible Note between the
Company and the Holder issued in connection therewith, each dated as of February
___, 2000.

     The purchase price per share of Common Stock issuable upon exercise of this
Warrant (the "Purchase Price") shall initially be $2.75; provided, however, that
the Purchase Price shall be adjusted from time to time as provided herein.

     As used herein the following terms, unless the context otherwise requires,
have the following respective meanings:

          (a) The term "Company" shall mean Dial-Thru International Corporation
     and any entity that shall succeed or assume the obligations of such
     corporation hereunder.

_______________________________________________________________________________

EXHIBIT A
<PAGE>

          (b) The term "Common Stock" means the Company's common stock, .001 par
     value per share.

          (c) The term "Warrant Shares" means as of any date during the Exercise
     Period, that number of shares of Common Stock which shall be exercisable by
     the Holder hereof pursuant to the terms of this Warrant.

     1.   Exercise of Warrant.
          -------------------

          1.1. Method of Exercise. This Warrant may be exercised in whole or in
               ------------------
     part (but not as to a fractional share of Common Stock), at any time and
     from time to time during the Exercise Period for up to, but not more than,
     the number of Warrant Shares at such time, by the Holder hereof by delivery
     to the Company at its principal office of (i) a notice of exercise (a
     "Notice of Exercise") substantially in the form attached hereto as Exhibit
                                                                        -------
     A, (ii) evidence satisfactory to the Company of the authority of the person
     -
     executing such Notice of Exercise, (iii) this Warrant, and (iv) payment of
     the Purchase Price multiplied by the number of shares of Common Stock for
     which this Warrant is being exercised (the "Exercise Price"). Payment of
     the Exercise Price shall be made by check or bank draft payable to the
     order of the Company or by wire transfer to the account of the Company. The
     shares so purchased shall be deemed to be issued as of the close of
     business on the date on which the Company shall have received from the
     Holder payment in full of the Exercise Price and the other documents
     referred to herein (the "Exercise Date").

     1.2.  Regulation D Restrictions. The Holder hereof represents and warrants
           -------------------------
     to the Company that it has acquired this Warrant and anticipates acquiring
     the shares of Common Stock issuable upon exercise of the Warrant solely for
     its own account for investment purposes and not with a view to or for
     distributing such securities unless such distribution has been registered
     with the Securities and Exchange Commission or an applicable exemption is
     available therefor. At the time this Warrant is exercised, the Company may
     require the Holder to state in the Notice of Exercise such representations
     concerning the Holder as are necessary or appropriate to assure compliance
     by the Holder with the Securities Act.

     2.   Delivery of Stock Certificates, etc., on Exercise. As soon as
          -------------------------------------------------
practicable after the exercise of this Warrant, the Company will cause to be
issued in the name of and delivered to the Holder a certificate for the number
of fully paid and nonassessable shares of Common Stock to which the Holder shall
be entitled on such exercise, plus, in lieu of any fractional share to which the
Holder would otherwise be entitled, cash equal to such fraction multiplied by
the then applicable Purchase Price, together with any other stock or other
securities and property (including cash, where applicable) to which the Holder
is entitled upon such exercise pursuant to Section 1 or otherwise.

     3.  Adjustments on Certain Capital Transactions. On the occurrence of any
         -------------------------------------------
of the following events, the following adjustments to the rights granted under
this Warrant shall be made:

_______________________________________________________________________________

EXHIBIT A
<PAGE>

          3.1.  In case the number of outstanding shares of Common Stock of the
     Company shall be increased by way of a stock dividend, stock split,
     recapitalization, or other similar means, the number of unexercised shares
     of Common Stock covered by this Warrant shall be increased by the amount
     that a like number of shares of outstanding Common Stock shall have been
     increased as a result of such stock increase and the Purchase Price shall
     be adjusted by multiplying the Purchase Price in effect immediately prior
     to such stock increase by a fraction, the numerator of which shall be the
     number of unexercised shares covered by this Warrant immediately prior to
     such stock increase and the denominator of which shall be the number of
     unexercised shares of Common Stock covered by this Warrant as adjusted for
     such stock increase.

          3.2.  In case the number of outstanding shares of Common Stock of the
     Company shall be reduced by recapitalization, reverse stock split or
     otherwise, the number of unexercised shares covered by this Warrant shall
     be reduced by the amount that a like number of shares of outstanding Common
     Stock shall have been reduced as a result of such stock reduction and the
     Purchase Price shall be adjusted by multiplying the Purchase Price in
     effect immediately prior to such stock reduction by a fraction, the
     numerator of which shall be the number of unexercised shares covered by
     this Warrant immediately prior to such stock reduction and the denominator
     of which shall be the number of unexercised shares covered by this Warrant
     as adjusted for such stock reduction.

          3.3.  In case the Company shall consolidate with or merge into another
     corporation, the holder of this Warrant will thereafter receive, upon the
     exercise thereof in accordance with the terms of this Warrant, the
     securities or property to which the holder of the number of shares of
     Common Stock then deliverable upon the exercise of this Warrant would have
     been entitled upon such consolidation or merger ("Other Securities") and
     the Company shall take such steps in connection with such consolidation or
     merger as may be necessary to assure that the provisions hereof shall
     thereafter be applicable, as nearly as reasonably may be, in relation to
     any securities or property thereafter deliverable upon the exercise of this
     Warrant.

     4.   Rights as a Shareholder. Holder shall not have any rights as a
          -----------------------
shareholder of the Company with respect to the shares subject to this Warrant.

     5.   Securities Law Requirements. Neither this Warrant nor the Warrant
          ---------------------------
Shares have been registered under the Securities Act or any state securities or
blue sky laws. Accordingly, upon (a) any transfer of this Warrant, any
transferee of this Warrant or (b) the exercise of this Warrant in whole or in
part, and if the Warrant Shares have not been registered under the Securities
Act, Holder or any other person exercising this Warrant shall, as applicable,
represent and agree in writing satisfactory to the Company that Holder or such
other person (a) is acquiring the shares for the purpose of investment and not
with a view to distribution thereof, (b) knows the shares have not been
registered under the Securities Act or any state securities or blue sky laws,
(c) understands that he must bear the economic risk of said investment for an
indefinite period of time until the shares are registered under the Securities
Act and applicable state securities or blue sky laws or an exemption from such
registration is available, and (d) will not

_______________________________________________________________________________

EXHIBIT A
<PAGE>

solicit any offer to sell or sell all or any portion of the shares other than
pursuant to an opinion of counsel reasonably satisfactory to the Company.

     6.   Reservation of Stock, etc. Issuable on Exercise of Warrant. The
          ----------------------------------------------------------
Company will at all times reserve and keep available, solely for issuance and
delivery on the exercise of this Warrant, all shares of Common Stock (or Other
Securities) from time to time issuable on the exercise of this Warrant.

     7.   Replacement of Warrant. On receipt of evidence reasonably satisfactory
          ----------------------
to the Company of the loss, theft, destruction or mutilation of this Warrant
and, in the case of any such loss, theft or destruction of this Warrant, on
delivery of an indemnity agreement or security satisfactory in form and amount
to the Company or, in the case of any such mutilation, on surrender and
cancellation of this Warrant, the Company at its expense will execute and
deliver, in lieu thereof, a new warrant of like tenor.

     8.   Notices, etc. All notices and other communications hereunder shall be
          ------------
personally delivered, telecopied or mailed by first class registered or
certified mail, postage prepaid, at such address of facsimile numbers as may
have been furnished to each party by the other in writing.

     9.   Miscellaneous. This Warrant and any term hereof may be changed,
          -------------
waived, discharged or terminated only by an instrument in writing signed by the
party against which enforcement of such change, waiver, discharge or termination
is sought. This Warrant shall be construed and enforced in accordance with and
governed by the internal laws of the State of Texas. The headings in this
Warrant are for purposes of reference only, and shall not limit or otherwise
affect any of the terms hereof. The invalidity or unenforceability of any
provision hereof shall in no way affect the validity or enforceability of any
other provision.

                           [SIGNATURE PAGE FOLLOWS]

_______________________________________________________________________________

EXHIBIT A
<PAGE>

     DATED as of August __, 2000.

                            DIAL-THRU INTERNATIONAL CORPORATION

                            By: _____________________________________
                            Name: ___________________________________
                            Title: __________________________________

                            Address:  8100 Jetstar Drive, Suite 100
                                      Irving, Texas  75063
                                      Fax: (972) 929-1616

                            HOLDER:
                            ------

                            _________________________________________

                            Address: _____________________
                                     _____________________
                                     _____________________
                                     Fax: ________________

_______________________________________________________________________________

EXHIBIT A
<PAGE>

                                   EXHIBIT A

                     FORM OF NOTICE OF EXERCISE - WARRANT
                     ------------------------------------

               (To be executed only upon exercise or conversion
                      of the Warrant in whole or in part)

To Dial-Thru International Corporation

     The undersigned registered holder of the accompanying Warrant hereby
exercises such Warrant or portion thereof for, and purchases thereunder,
______________/1/ shares of Common Stock (as defined in such Warrant) and
herewith makes payment therefor of $__________ as of the date written below. The
undersigned requests that the certificates for such shares of Common Stock be
issued in the name of, and delivered to, _________________________________ whose
address is ____________________________________________________________________.

Dated:  ____________________

                            __________________________________________________
                            (Name must conform to name of holder as specified
                            on the face of the Warrant)

                            By: ______________________________________________
                            Name: ____________________________________________
                            Title: ___________________________________________

                            Address of holder:

                            __________________________________________________
                            __________________________________________________
                            __________________________________________________

Date of exercise: __________

________________________

/1/  Insert the number of shares of Common Stock as to which the accompanying
Warrant is being exercised. In the case of a partial exercise, a new Warrant or
Warrants will be issued and delivered, representing the unexercised portion of
the accompanying Warrant, to the holder surrendering the same.

________________________________________________________________________________

EXHIBIT A
<PAGE>

                            Schedule of Information
                         Omitted from Convertible Note
                                (9 Notes Total)

Holder                         Note Amount
------                         -----------

John L. Strauss                 $  300,000
John D. Lelong                  $    50,00
Robert B. Irwin                 $  100,000
Henry Hermann                   $  200,000
Carl P. Jayson                  $   50,000
Peter P. Smith                  $  125,000
Lester V. Murphy                $   50,000
Fred Kull                       $   25,000
Brandon M. Dauson               $  100,000
                                ----------
     Total                      $1,000,000

________________________________________________________________________________

EXHIBIT 4.1

Source: [{"source": "alea-institute/alea-institute/kl3m-data-edgar-agreements/train-00010-of-00352.parquet"}, [{"source": "alea-institute/alea-institute/kl3m-data-edgar-agreements/train-00010-of-00352.parquet"}]]