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                                                                     Exhibit 4.9

                         REGISTRATION RIGHTS AGREEMENT

          This Registration Rights Agreement, dated as of February 22, 2000
(this "Agreement"), between American TeleSource International, Inc., a Delaware
corporation, with principal executive offices located at 12500 Network
Boulevard, Suite 407, San Antonio 78249 (the "Company"), and The Shaar Fund Ltd.
(the "Initial Investor").

          Whereas, upon the terms and subject to the conditions of the
Securities Purchase Agreement dated as of February 22, 2000, between the Initial
Investor and the Company (the "Securities Purchase Agreement"), the Company has
agreed to issue and sell to the Initial Investor (i) 3,000 shares of its Series
D 6% Convertible Preferred Stock, par value $0.001 per share (the "Preferred
Shares"), which, upon the terms and subject to the conditions of the Company's
Certificate of Designation of Series D 6% Convertible Preferred Stock (the
"Certificate of Designation"), are convertible into shares of the Company's
common stock, par value $0.001 per share (the "Common Stock") and (ii) Common
Stock Purchase Warrants (the "Initial Warrants") to purchase 150,000 shares of
Common Stock;

          Whereas, upon the terms and subject to the conditions of the
Certificate of Designation, the Preferred Shares may be redeemed by the Company
at a redemption price which includes, but is not limited to, the issuance of its
Common Stock Purchase Warrants having the same terms and conditions as the
Initial Warrants and exercisable to purchase an additional 150,000 shares of
Common Stock (the "Redemption Warrants" and, together with the Initial Warrants,
the "Warrants"); and

          Whereas, to induce the Initial Investor to execute and deliver the
Securities Purchase Agreement, the Company has agreed to provide with respect to
the Common Stock issued or issuable in lieu of cash dividend payments on the
Preferred Shares, upon conversion of the Preferred Shares and upon exercise of
the Warrants certain registration rights under the Securities Act;

          Now, Therefore, in consideration of the premises and the mutual
covenants contained herein, the parties hereto, intending to be legally bound,
hereby agree as follows:

          1.   Definitions

          (a)  As used in this Agreement, the following terms shall have the
meanings:

     (i)    "Affiliate," of any specified Person means any other Person who
     directly, or indirectly through one or more intermediaries, is in control
     of, is controlled by, or is under common control with, such specified
     Person.  For purposes of this definition, control of a Person means the
     power, directly or indirectly, to direct or cause the direction of the
     management and policies of such Person whether by contract, securities,
     ownership or otherwise; and the terms "controlling" and "controlled" have
     the respective meanings correlative to the foregoing.

     (ii)   "Commission" means the Securities and Exchange Commission.

     (iii)  "Current Market Price" on any date of determination means the
     closing price of a share of the Common Stock on such day as reported on The
     American Stock Exchange (the "Amex") or, if such security is not listed on
     the Amex, on the principal national security exchange or quotation system
     on which such security is quoted or listed or admitted to trading, or, if
     not quoted or listed

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     or admitted to trading on any national securities exchange or quotation
     system, the closing bid price of such security on the over-the-counter
     market on the day in question as reported by Bloomberg LP, or a similar
     generally accepted reporting service, as the case may be.

     (iv)   "Exchange Act" means the Securities Exchange Act of 1934, as
     amended, and the rules and regulations of the Commission thereunder, or any
     similar successor statute.

     (v)    "Investors" means the Initial Investor and any transferee or
     assignee of Registrable Securities who agrees to become bound by all of the
     terms and provisions of this Agreement in accordance with Section 8 hereof.

     (vi)   "Person" means any individual, partnership, corporation, limited
     liability company, joint stock company, association, trust, unincorporated
     organization, or a government or agency or political subdivision thereof.

     (vii)  "Prospectus" means the prospectus (excluding any preliminary
     prospectus but including, without limitation, any final prospectus filed
     pursuant to Rule 424(b) under the Securities Act and any prospectus that
     discloses information previously omitted from a prospectus filed as part of
     an effective registration statement in reliance on Rule 430A under the
     Securities Act) included in the Registration Statement, as amended or
     supplemented by any prospectus supplement with respect to the terms of the
     offering of any portion of the Registrable Securities covered by the
     Registration Statement and by all other amendments and supplements to such
     prospectus, including all material incorporated by reference in such
     prospectus and all documents filed after the date of such prospectus by the
     Company under the Exchange Act and incorporated by reference therein.

     (viii) "Public Offering" means an offer registered with the Commission and
     the appropriate state securities commissions by the Company of its Common
     Stock and made pursuant to the Securities Act.

     (ix)   "Registrable Securities" means the Common Stock issued or issuable
     (i) in lieu of cash dividend payments on the Preferred Shares, (ii) upon
     conversion of the Preferred Shares or (iii) upon exercise of the Warrants;
     provided, however, a share of Common Stock shall cease to be a Registrable
     Security for purposes of this Agreement when it no longer is a Restricted
     Security.

     (x)    "Registration Statement" means a registration statement of the
     Company filed on an appropriate form under the Securities Act providing for
     the registration of, and the sale on a continuous or delayed basis by the
     holders of, all of the Registrable Securities pursuant to Rule 415 under
     the Securities Act, including the Prospectus contained therein and forming
     a part thereof, any amendments to such registration statement and
     supplements to such Prospectus, and all exhibits and other material
     incorporated by reference in such registration statement and Prospectus.

     (xi)   "Restricted Security" means any share of Common Stock issued or
     issuable in lieu of cash dividend payments on the Preferred Shares, upon
     conversion of the Preferred Shares or upon exercise of the Warrants except
     any such share that (i) has been registered pursuant to an effective
     registration statement under the Securities Act and sold in a manner
     contemplated by the prospectus included in such registration statement,
     (ii) has been transferred in compliance with the resale provisions of Rule
     144 under the Securities Act (or any successor provision thereto) or is
     transferable pursuant to paragraph (k) of Rule 144 under the Securities Act
     (or any successor provision thereto), or (iii) otherwise has been
     transferred and a new share of Common Stock not subject to transfer
     restrictions under the Securities Act has been delivered by or on behalf of
     the Company.

     (xii)  "Securities Act" means the Securities Act of 1933, as amended, and
     the rules and regulations of the Commission thereunder, or any similar
     successor statute.

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          (b) All capitalized terms used and not defined herein have the
respective meaning assigned to them in the Securities Purchase Agreement.

          2.   Registration

          (a)  Filing and Effectiveness of Registration Statement.  The Company
shall prepare and file with the Commission not later than April 1, 2000, a
Registration Statement relating to the offer and sale of the Registrable
Securities and shall use its best efforts to cause the Commission to declare
such Registration Statement effective under the Securities Act as promptly as
practicable but not later than June 1, 2000, assuming for purposes hereof a
Conversion Price (as defined in the Certificate of Designation) of $2.50.  The
Company shall not include any other securities in the Registration Statement
relating to the offer and sale of the Registrable Securities.  The Company shall
notify the Initial Investor by written notice that such Registration Statement
has been declared effective by the Commission within 24 hours of such
declaration by the Commission.

          (b)  Registration Default.  If the Registration Statement covering the
Registrable Securities or the Additional Registrable Securities (as defined in
Section 2(d) hereof) required to be filed by the Company pursuant to Section
2(a) or 2(d) hereof, as the case may be, is not (i) filed with the Commission on
or before April 1, 2000 or (ii) declared effective by the Commission on or
before June 1, 2000 (either of which, without duplication, an "Initial Date"),
then the Company shall make the payments to the Initial Investor as provided in
the next sentence as liquidated damages and not as a penalty.  The amount to be
paid by the Company to the Initial Investor shall be determined as of each
Computation Date (as defined below), and such amount shall be equal to 2% (the
"Liquidated Damage Rate") of the Purchase Price (as defined in the Securities
Purchase Agreement) from the Initial Date to the first Computation Date and for
each Computation Date thereafter, calculated on a pro rata basis to the date on
which the Registration Statement is filed with (in the event of an Initial Date
pursuant to clause (i) above) or declared effective by (in the event of an
Initial Date pursuant to clause (ii) above) the Commission (the "Periodic
Amount") provided, however, that in no event shall the liquidated damages be
less than $25,000.  The full Periodic Amount shall be paid by the Company to the
Initial Investor by wire transfer of immediately available funds within three
days after each Computation Date.

          As used in this Section 2(b), "Computation Date" means the date which
is 30 days after the Initial Date and, if the Registration Statement required to
be filed by the Company pursuant to Section 2(a) has not theretofore been
declared effective by the Commission, each date which is 30 days after the
previous Computation Date until such Registration Statement is so declared
effective.

          Notwithstanding the above, if the Registration Statement covering the
Registrable Securities or the Additional Registrable Securities required to be
filed by the Company pursuant to Section 2(a) or 2(d) hereof, as the case may
be, is not filed with the Commission by April 1, 2000, the Company shall be in
default of this Registration Rights Agreement, and the Initial Investor shall be
entitled to liquidated damages as set forth above.

          (c)  Eligibility for Use of Form S-3.  The Company agrees that at such
time as it meets all the requirements for the use of Securities Act Registration
Statement on Form S-3 it shall file all reports and information required to be
filed by it with the Commission in a timely manner and take all such other
action so as to maintain such eligibility for the use of such form.

          (d)  Additional Registration Statement.  In the event the Current
Market Price declines to $3.00 per share or less, as the same may be adjusted
from time to time for any subdivision or combination of shares of Common Stock
after the date hereof (the date of such event, the "Decline Date"), the Company
shall, to the extent required by the Securities Act (because the additional
shares were not covered by the Registration Statement filed pursuant to Section
2(a)), as reasonably determined by the Initial Investor, file an additional
Registration Statement with the Commission for such additional number of
Registrable Securities as would be issuable upon conversion of the Preferred
Shares and exercise of the Warrants (the "Additional Registrable Securities") in
addition to those previously registered, assuming a Conversion Price (as defined
in the Certificate of Designation) of $0.30 per share.  The Company shall, to
the extent required by the Securities Act, as reasonably determined by the
Initial Investor, prepare and file with the Commission not later than the 30th
day thereafter, a Registration Statement relating to the offer and sale of such
Additional Registrable Securities and shall use its best efforts to cause the
Commission to declare such Registration Statement effective under the Securities
Act as promptly as practicable but

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not later than 60 days thereafter. The Company shall not include any other
securities in the Registration Statement relating to the offer and sale of such
Additional Registrable Securities.

          If the Additional Registration Statement is not (i) filed with the
Commission within 30 days after the Decline Date or (ii) declared effective by
the Commission within 90 days after the Decline Date (either of which, without
duplication, an "Additional Registration Date"), then the Company shall make the
payments to the Initial Investor at the Liquidated Damage Rate from the
Additional Registration Date to the first Additional Computation Date and for
each Additional Computation Date thereafter, calculated on a pro rata basis to
the date on which the Additional Registration Statement is filed with (in the
event of an Additional Registration Date pursuant to clause (i) above) or
declared effective by (in the event of an Additional Registration Date pursuant
to clause (ii) above) the Commission (the "Additional Periodic Amount")
provided, however, that in no event shall the liquidated damages be less than
$25,000.  The full Additional Periodic Amount shall be paid by the Company to
the Initial Investor by wire transfer of immediately available funds within
three days after each Additional Computation Date.

          As used in this Section 2(d), "Additional Computation Date" means the
date which is 30 days after the Additional Registration Date and, if the
Additional Registration Statement required to be filed by the Company pursuant
to this Section 2(d) has not theretofore been declared effective by the
Commission, each date which is 30 days after the previous Additional Computation
Date until such Additional Registration Statement is so declared effective.

          (e)  (i)  If the Company proposes to register any of its warrants,
     Common Stock or any other shares of common stock of the Company under the
     Securities Act (other than a registration (A) on Form S-8 or S-4 or any
     successor or similar forms, (B) relating to Common Stock or any other
     shares of common stock of the Company issuable upon exercise of employee
     share options or in connection with any employee benefit or similar plan of
     the Company or (C) in connection with a direct or indirect acquisition by
     the Company of another Person or any transaction with respect to which Rule
     145 (or any successor provision) under the Securities Act applies), whether
     or not for sale for its own account, it will each such time, give prompt
     written notice at least 20 days prior to the anticipated filing date of the
     registration statement relating to such registration to the Initial
     Investor, which notice shall set forth such Initial Investor's rights under
     this Section 3(e) and shall offer the Initial Investor the opportunity to
     include in such registration statement such number of Registrable
     Securities as the Initial Investor may request. Upon the written request of
     an Initial Investor made within 10 days after the receipt of notice from
     the Company (which request shall specify the number of Registrable
     Securities intended to be disposed of by such Initial Investor), the
     Company will use its best efforts to effect the registration under the
     Securities Act of all Registrable Securities that the Company has been so
     requested to register by the Initial Investor, to the extent requisite to
     permit the disposition of the Registrable Securities so to be registered;
     provided, however, that (A) if such registration involves a Public
     Offering, the Initial Investor must sell its Registrable Securities to the
     underwriters selected as provided in Section 3(b) hereof on the same terms
     and conditions as apply to the Company and (B) if, at any time after giving
     written notice of its intention to register any Registrable Securities
     pursuant to this Section 3 and prior to the effective date of the
     registration statement filed in connection with such registration, the
     Company shall determine for any reason not to register such Registrable
     Securities, the Company shall give written notice to the Initial Investor
     and, thereupon, shall be relieved of its obligation to register any
     Registrable Securities in connection with such registration. The Company's
     obligations under this Section 2(e) shall terminate on the date that the
     registration statement to be filed in accordance with Section 2(a) is
     declared effective by the Commission.

     (ii)   If a registration pursuant to this Section 2(e) involves a Public
     Offering and the managing underwriter thereof advises the Company that, in
     its view, the number of shares of Common Stock, warrants or other shares of
     Common Stock that the Company and the Initial Investor intend to include in
     such registration exceeds the largest number of shares of Common Stock or
     warrants (including any other shares of Common Stock or warrants of the
     Company) that can be sold without having an adverse effect on such Public
     Offering (the "Maximum Offering Size"), the Company will include in such
     registration only that number of shares of Common Stock or warrants, as
     applicable, which does not exceed the Maximum Offering Size, with the
     difference between the number of shares in the Maximum Offering Size and
     the number of shares originally

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     intended for inclusion (including the Common Stock covered by this
     Agreement, all shares and warrants originally intended to be issued and
     sold by the Company ("Company Shares") and all shares requested for
     inclusion by selling shareholders other than the Initial Investor pursuant
     to any registration rights agreement now in effect ("Third-Party Shares"))
     to be allocated among the Initial Investor, such other selling shareholders
     and the Company pro rata on the basis of the relative number of shares of
     Common Stock covered by this Agreement, Third-Party Shares and Company
     Shares, respectively.

          If as a result of the proration provisions of this Section 2(e)(ii),
any Initial Investor is not entitled to include all such Registrable Securities
in such registration, such Initial Investor may elect to withdraw its request to
include any Registrable Securities in such registration.  With respect to
registrations pursuant to this Section 2(e), the number of securities required
to satisfy any underwriters' over-allotment option shall be allocated among the
Initial Investor, such other selling shareholders and the Company pro rata on
the basis of the relative number of shares of Common Stock covered by this
Agreement, Third-Party Shares and Company Shares, respectively.

          3.   Obligations of the Company

          In connection with the registration of the Registrable Securities, the
Company shall:

          (a)  Promptly (i) prepare and file with the Commission such amendments
(including post-effective amendments) to the Registration Statement and
supplements to the Prospectus as may be necessary to keep the Registration
Statement continuously effective and in compliance with the provisions of the
Securities Act applicable thereto so as to permit the Prospectus forming part
thereof to be current and useable by Investors for resales of the Registrable
Securities for a period of two years from the date on which the Registration
Statement is first declared effective by the Commission (the "Effective Time")
or such shorter period that will terminate when all the Registrable Securities
covered by the Registration Statement have been sold pursuant thereto in
accordance with the plan of distribution provided in the Prospectus, transferred
pursuant to Rule 144 under the Securities Act or otherwise transferred in a
manner that results in the delivery of new securities not subject to transfer
restrictions under the Securities Act (the "Registration Period") and (ii) take
all lawful action such that each of (A) the Registration Statement and any
amendment thereto does not, when it becomes effective, contain an untrue
statement of a material fact or omit to state a material fact required to be
stated therein or necessary to make the statements therein, not misleading and
(B) the Prospectus forming part of the Registration Statement, and any amendment
or supplement thereto, does not at any time during the Registration Period
include an untrue statement of a material fact or omit to state a material fact
required to be stated therein or necessary to make the statements therein, in
light of the circumstances under which they were made, not misleading;

          (b) During the Registration Period, comply with the provisions of the
Securities Act with respect to the Registrable Securities of the Company covered
by the Registration Statement until such time as all of such Registrable
Securities have been disposed of in accordance with the intended methods of
disposition by the Investors as set forth in the Prospectus forming part of the
Registration Statement;

          (c) (i) Prior to the filing with the Commission of any Registration
Statement (including any amendments thereto) and the distribution or delivery of
any Prospectus (including any supplements thereto), provide draft copies thereof
(including a copy of the accountant's consent letter to be included in the
filing) to the Investors and reflect in such documents all such comments as the
Investors reasonably may propose and (ii) furnish to each Investor whose
Registrable Securities are included in the Registration Statement and its legal
counsel identified to the Company, (A) promptly after the same is prepared and
publicly distributed, filed with the Commission, or received by the Company, one
copy of the Registration Statement, each Prospectus, and each amendment or
supplement thereto, and (B) such number of copies of the Prospectus and all
amendments and supplements thereto and such other documents, as such Investor
may reasonably request in order to facilitate the disposition of the Registrable
Securities owned by such Investor;

          (d) (i) Register or qualify the Registrable Securities covered by the
Registration Statement under such securities or "blue sky" laws of such
jurisdictions as the Investors who hold a majority-in-interest of the
Registrable Securities being offered reasonably request, (ii) prepare and file
in such jurisdictions such amendments (including post-effective amendments) and
supplements to such registrations and qualifications as may be necessary

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to maintain the effectiveness thereof at all times during the Registration
Period, (iii) take all such other lawful actions as may be necessary to maintain
such registrations and qualifications in effect at all times during the
Registration Period, and (iv) take all such other lawful actions reasonably
necessary or advisable to qualify the Registrable Securities for sale in such
jurisdictions; provided, however, that the Company shall not be required in
connection therewith or as a condition thereto to (A) qualify to do business in
any jurisdiction where it would not otherwise be required to qualify but for
this Section 3(d), (B) subject itself to general taxation in any such
jurisdiction or (C) file a general consent to service of process in any such
jurisdiction;

          (e)  As promptly as practicable after becoming aware of such event,
notify each Investor of the occurrence of any event, as a result of which the
Prospectus included in the Registration Statement, as then in effect, includes
an untrue statement of a material fact or omits to state a material fact
required to be stated therein or necessary to make the statements therein, in
light of the circumstances under which they were made, not misleading, and
promptly prepare an amendment to the Registration Statement and supplement to
the Prospectus to correct such untrue statement or omission, and deliver a
number of copies of such supplement and amendment to each Investor as such
Investor may reasonably request;

          (f)  As promptly as practicable after becoming aware of such event,
notify each Investor who holds Registrable Securities being sold (or, in the
event of an underwritten offering, the managing underwriters) of the issuance by
the Commission of any stop order or other suspension of the effectiveness of the
Registration Statement at the earliest possible time and take all lawful action
to effect the withdrawal, recession or removal of such stop order or other
suspension;

          (g)  Cause all the Registrable Securities covered by the Registration
Statement to be listed on the principal national securities exchange, and
included in an inter-dealer quotation system of a registered national securities
association, on or in which securities of the same class or series issued by the
Company are then listed or included;

          (h)  Maintain a transfer agent and registrar, which may be a single
entity, for the Registrable Securities not later than the effective date of the
Registration Statement;

          (i)  Cooperate with the Investors who hold Registrable Securities
being offered to facilitate the timely preparation and delivery of certificates
for the Registrable Securities to be offered pursuant to the registration
statement and enable such certificates for the Registrable Securities to be in
such denominations or amounts, as the case may be, as the Investors reasonably
may request and registered in such names as the Investor may request; and,
within three business days after a registration statement which includes
Registrable Securities is declared effective by the Commission, deliver and
cause legal counsel selected by the Company to deliver to the transfer agent for
the Registrable Securities (with copies to the Investors whose Registrable
Securities are included in such registration statement) an appropriate
instruction and, to the extent necessary, an opinion of such counsel;

          (j)  Take all such other lawful actions reasonably necessary to
expedite and facilitate the disposition by the Investors of their Registrable
Securities in accordance with the intended methods therefor provided in the
Prospectus which are customary under the circumstances;

          (k)  Make generally available to its security holders as soon as
practicable, but in any event not later than three (3) months after (i) the
effective date (as defined in Rule 158(c) under the Securities Act) of the
Registration Statement, and (ii) the effective date of each post-effective
amendment to the Registration Statement, as the case may be, an earnings
statement of the Company and its subsidiaries complying with Section 11(a) of
the Securities Act and the rules and regulations of the Commission thereunder
(including, at the option of the Company, Rule 158);

          (1)  In the event of an underwritten offering, promptly include or
incorporate in a Prospectus supplement or post-effective amendment to the
Registration Statement such information as the managers reasonably agree should
be included therein and to which the Company does not reasonably object and make
all required filings of such Prospectus supplement or post-effective amendment
as soon as practicable after it is notified of the matters to be included or
incorporated in such Prospectus supplement or post-effective amendment;

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          (m)  (i) Make reasonably available for inspection by Investors, any
underwriter participating in any disposition pursuant to the Registration
Statement, and any attorney, accountant or other agent retained by such
Investors or any such underwriter all relevant financial and other records,
pertinent corporate documents and properties of the Company and its
subsidiaries, and (ii) cause the Company's officers, directors and employees to
supply all information reasonably requested by such Investors or any such
underwriter, attorney, accountant or agent in connection with the Registration
Statement, in each case, as is customary for similar due diligence examinations;
provided, however, that all records, information and documents that are
designated in writing by the Company as confidential, proprietary or containing
any material nonpublic information shall be kept confidential by such Investors
and any such underwriter, attorney, accountant or agent (pursuant to an
appropriate confidentiality agreement in the case of any such holder or agent),
unless such disclosure is made pursuant to judicial process in a court
proceeding (after first giving the Company an opportunity promptly to seek a
protective order or otherwise limit the scope of the information sought to be
disclosed) or is required by law, or such records, information or documents
become available to the public generally or through a third party not in
violation of an accompanying obligation of confidentiality; and provided,
further, that, if the foregoing inspection and information gathering would
otherwise disrupt the Company's conduct of its business, such inspection and
information gathering shall, to the maximum extent possible, be coordinated on
behalf of the Investors and the other parties entitled thereto by one firm of
counsel designed by and on behalf of the majority in interest of Investors and
other parties;

          (n)  In connection with any underwritten offering, make such
representations and warranties to the Investors participating in such
underwritten offering and to the managers, in form, substance and scope as are
customarily made by the Company to underwriters in secondary underwritten
offerings;

          (o)  In connection with any underwritten offering, obtain opinions of
counsel to the Company (which counsel and opinions (in form, scope and
substance) shall be reasonably satisfactory to the managers) addressed to the
underwriters, covering such matters as are customarily covered in opinions
requested in secondary underwritten offerings (it being agreed that the matters
to be covered by such opinions shall include, without limitation, as of the date
of the opinion and as of the Effective Time of the Registration Statement or
most recent post-effective amendment thereto, as the case may be, the absence
from the Registration Statement and the Prospectus, including any documents
incorporated by reference therein, of an untrue statement of a material fact or
the omission of a material fact required to be stated therein or necessary to
make the statements therein (in the case of the Prospectus, in light of the
circumstances under which they were made) not misleading, subject to customary
limitations);

          (p)  In connection with any underwritten offering, obtain "cold
comfort" letters and updates thereof from the independent public accountants of
the Company (and, if necessary, from the independent public accountants of any
subsidiary of the Company or of any business acquired by the Company, in each
case for which financial statements and financial data are, or are required to
be, included in the Registration Statement), addressed to each underwriter
participating in such underwritten offering (if such underwriter has provided
such letter, representations or documentation, if any, required for such cold
comfort letter to be so addressed), in customary form and covering matters of
the type customarily covered in "cold comfort" letters in connection with
secondary underwritten offerings;

          (q)  In connection with any underwritten offering, deliver such
documents and certificates as may be reasonably required by the managers, if
any; and

          (r)  In the event that any broker-dealer registered under the Exchange
Act shall be an "Affiliate" (as defined in Rule 2729(b)(1) of the rules and
regulations of the National Association of Securities Dealers, Inc. (the "NASD
Rules") (or any successor provision thereto)) of the Company or has a "conflict
of interest" (as defined in Rule 2720(b)(7) of the NASD Rules (or any successor
provision thereto)) and such broker-dealer shall underwrite, participate as a
member of an underwriting syndicate or selling group or assist in the
distribution of any Registrable Securities covered by the Registration
Statement, whether as a holder of such Registrable Securities or as an
underwriter, a placement or sales agent or a broker or dealer in respect
thereof, or otherwise, the Company shall assist such broker-dealer in complying
with the requirements of the NASD Rules, including, without limitation, by (A)
engaging a "qualified independent underwriter" (as defined in Rule 2720(b)(15)
of the NASD Rules (or any successor provision thereto)) to participate in the
preparation of the Registration Statement relating to such Registrable
Securities, to exercise usual standards of due diligence in respect

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thereof and to recommend the public offering price of such Registrable
Securities, (B) indemnifying such qualified independent underwriter to the
extent of the indemnification of underwriters provided in Section 5 hereof, and
(C) providing such information to such broker-dealer as may be required in order
for such broker-dealer to comply with the requirements of the NASD Rules.

          4.   Obligations of the Investors

          In connection with the registration of the Registrable Securities, the
Investors shall have the following obligations:

          (a)  It shall be a condition precedent to the obligations of the
Company to complete the registration pursuant to this Agreement with respect to
the Registrable Securities of a particular Investor that such Investor shall
furnish to the Company such information regarding itself, the Registrable
Securities held by it and the intended method of disposition of the Registrable
Securities held by it as shall be reasonably required to effect the registration
of such Registrable Securities and shall execute such documents in connection
with such registration as the Company may reasonably request.  As least seven
days prior to the first anticipated filing date of the Registration Statement,
the Company shall notify each Investor of the information the Company requires
from each such Investor (the "Requested Information") if such Investor elects to
have any of its Registrable Securities included in the Registration Statement.
If at least two business days prior to the anticipated filing date the Company
has not received the Requested Information from in Investor (a "Non-Responsive
Investor"), then the Company may file the Registration Statement without
including Registrable Securities of such Non-Responsive Investor and have no
further obligations to the Non-Responsive Investor;

          (b)  Each Investor by its acceptance of the Registrable Securities
agrees to cooperate with the Company in connection with the preparation and
filing of the Registration Statement hereunder, unless such Investor has
notified the Company in writing of its election to exclude all of its
Registrable Securities from the Registration Statement; and

          (c)  Each Investor agrees that, upon receipt of any notice from the
Company of the occurrence of any event of the kind described in Section 3(e) or
3(f), it shall immediately discontinue its disposition of Registrable Securities
pursuant to the Registration Statement covering such Registrable Securities
until such Investor's receipt of the copies of the supplemented or amended
Prospectus contemplated by Section 3(e) and, if so directed by the Company, such
Investor shall deliver to the Company (at the expense of the Company) or destroy
(and deliver to the Company a certificate of destruction) all copies in such
Investor's possession, of the Prospectus covering such Registrable Securities
current at the time of receipt of such notice.

          5.   Expenses of Registration

          All expenses, other than underwriting discounts and commissions,
incurred in connection with registrations, filings or qualifications pursuant to
Section 3, but including, without limitation, all registration, listing, and
qualifications fees, printing and engraving fees, accounting fees, and the fees
and disbursements of counsel for the Company, and the reasonable fees of one
firm of counsel to the holders of a majority in interest of the Registrable
Securities shall be borne by the Company.

          6.   Indemnification and Contribution

          (a)  The Company shall indemnify and hold harmless each Investor and
each underwriter, if any, which facilitates the disposition of Registrable
Securities, and each of their respective officers and directors and each person
who controls such Investor or underwriter within the meaning of Section 15 of
the Securities Act or Section 20 of the Exchange Act (each such person being
sometimes hereinafter referred to as an "Indemnified Person") from and against
any losses, claims, damages or liabilities, joint or several, to which such
Indemnified Person may become subject under the Securities Act or otherwise,
insofar as such losses, claims, damages or liabilities (or actions in respect
thereof) arise out of or are based upon an untrue statement or alleged untrue
statement of a material fact contained in any Registration Statement or an
omission or alleged omission to state therein a material fact required to be
stated therein or necessary to make the statements therein, not misleading, or

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arise out of or are based upon an untrue statement or alleged untrue statement
of a material fact contained in any Prospectus or an omission or alleged
omission to state therein a material fact required to be stated therein or
necessary to make the statements therein, in the light of the circumstances
under which they were made, not misleading; and the Company hereby agrees to
reimburse such Indemnified Person for all reasonable legal and other expenses
incurred by them in connection with investigating or defending any such action
or claim as and when such expenses are incurred; provided, however, that the
Company shall not be liable to any such Indemnified Person in any such case to
the extent that any such loss, claim, damage or liability arises out of or is
based upon (i) an untrue statement or alleged untrue statement made in, or an
omission or alleged omission from, such Registration Statement or Prospectus in
reliance upon and in conformity with written information furnished to the
Company by such Indemnified Person expressly for use therein or (ii) in the case
of the occurrence of an event of the type specified in Section 3(e), the use by
the Indemnified Person of an outdated or defective Prospectus after the Company
has provided to such Indemnified Person written notice that such Prospectus is
outdated or defective.

          (b)  Indemnification by the Investors and Underwriters.  Each Investor
agrees, as a consequence of the inclusion of any of its Registrable Securities
in a Registration Statement, and each underwriter, if any, which facilitates the
disposition of Registrable Securities shall agree, as a consequence of
facilitating such disposition of Registrable Securities, severally and not
jointly, to (i) indemnify and hold harmless the Company, its directors
(including any person who, with his or her consent, is named in the Registration
Statement as a director nominee of the Company), its officers and each person,
if any, who controls the Company within the meaning of either Section 15 of the
Securities Act or Section 20 of the Exchange Act, against any losses, claims,
damages or liabilities to which the Company or such other persons may become
subject, under the Securities Act or otherwise, insofar as such losses, claims,
damages or liabilities (or actions in respect thereof) arise out of or are based
upon an untrue statement or alleged untrue statement of a material fact
contained in such Registration Statement or Prospectus or arise out of or are
based upon the omission or alleged omission to state therein a material fact
required to be stated therein or necessary to make the statements therein (in
light of the circumstances under which they were made, in the case of the
Prospectus), not misleading, in each case to the extent, but only to the extent,
that such untrue statement or alleged untrue statement or omission or alleged
omission was made in reliance upon and in conformity with written information
furnished to the Company by such holder or underwriter expressly for use
therein; provided, however, that no Investor or underwriter shall be liable
under this Section 6(b) for any amount in excess of the net proceeds paid to
such Investor or underwriter in respect of shares sold by it, and (ii) reimburse
the Company for any legal or other expenses incurred by the Company in
connection with investigating or defending any such action or claim as such
expenses are incurred.

          (c)  Notice of Claims, etc.  Promptly after receipt by a party seeking
indemnification pursuant to this Section 6 (an "Indemnified Party") of written
notice of any investigation, claim, proceeding or other action in respect of
which indemnification is being sought (each, a "Claim"), the Indemnified Party
promptly shall notify the party against whom indemnification pursuant to this
Section 6 is being sought (the "Indemnifying Party") of the commencement
thereof; but the omission to so notify the Indemnifying Party shall not relieve
it from any liability that it otherwise may have to the Indemnified Party,
except to the extent that the Indemnifying Party is materially prejudiced and
forfeits substantive rights and defenses by reason of such failure.  In
connection with any Claim as to which both the Indemnifying Party and the
Indemnified Party are parties, the Indemnifying Party shall be entitled to
assume the defense thereof.  Notwithstanding the assumption of the defense of
any Claim by the Indemnifying Party, the Indemnified Party shall have the right
to employ separate legal counsel and to participate in the defense of such
Claim, and the Indemnifying Party shall bear the reasonable fees, out-of-pocket
costs and expenses of such separate legal counsel to the Indemnified Party if
(and only if): (x) the Indemnifying Party shall have agreed to pay such fees,
costs and expenses, (y) the Indemnified Party and the Indemnifying Party shall
reasonably have concluded that representation of the Indemnified Party by the
Indemnifying Party by the same legal counsel would not be appropriate due to
actual or, as reasonably determined by legal counsel to the Indemnified Party,
potentially differing interests between such parties in the conduct of the
defense of such Claim, or if there may be legal defenses available to the
Indemnified Party that are in addition to or disparate from those available to
the Indemnifying Party, or (z) the Indemnifying Party shall have failed to
employ legal counsel reasonably satisfactory to the Indemnified Party within a
reasonable period of time after notice of the commencement of such Claim.  If
the Indemnified Party employs separate legal counsel in circumstances other than
as described in clauses (x), (y) or (z) above, the fees, costs and expenses of
such legal counsel shall be borne exclusively by the Indemnified Party.  Except
as provided above, the Indemnifying Party shall not, in connection with any
Claim in the same jurisdiction, be liable for the fees and expenses of more than
one firm of counsel for the Indemnified Party (together

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<PAGE>

with appropriate local counsel). The Indemnified Party shall not, without the
prior written consent of the Indemnifying Party (which consent shall not
unreasonably be withheld), settle or compromise any Claim or consent to the
entry of any judgment that does not include an unconditional release of the
Indemnifying Party from all liabilities with respect to such Claim or judgment.

          (d)  Contribution. If the indemnification provided for in this Section
6 is unavailable to or insufficient to hold harmless an Indemnified Person under
subsection (a) or (b) above in respect of any losses, claims, damages or
liabilities (or actions in respect thereof) referred to therein, then each
Indemnifying Party shall contribute to the amount paid or payable by such
Indemnified Party as a result of such losses, claims, damages or liabilities (or
actions in respect thereof) in such proportion as is appropriate to reflect the
relative fault of the Indemnifying Party and the Indemnified Party in connection
with the statements or omissions which resulted in such losses, claims, damages
or liabilities (or actions in respect thereof), as well as any other relevant
equitable considerations. The relative fault of such Indemnifying Party and
Indemnified Party shall be determined by reference to, among other things,
whether the untrue or alleged untrue statement of a material fact or omission or
alleged omission to state a material fact relates to information supplied by
such Indemnifying Party or by such Indemnified Party, and the parties' relative
intent, knowledge, access to information and opportunity to correct or prevent
such statement or omission. The parties hereto agree that it would not be just
and equitable if contribution pursuant to this Section 6(d) were determined by
pro rata allocation (even if the Investors or any underwriters were treated as
one entity for such purpose) or by any other method of allocation which does not
take account of the equitable considerations referred to in this Section 6(d).
The amount paid or payable by an Indemnified Party as a result of the losses,
claims, damages or liabilities (or actions in respect thereof) referred to above
shall be deemed to include any legal or other fees or expenses reasonably
incurred by such Indemnified Party in connection with investigating or defending
any such action or claim. No person guilty of fraudulent misrepresentation
(within the meaning of Section 11(f) of the Securities Act) shall be entitled to
contribution from any person who was not guilty of such fraudulent
misrepresentation. The obligations of the Investors and any underwriters in this
Section 6(d) to contribute shall be several in proportion to the percentage of
Registrable Securities registered or underwritten, as the case may be, by them
and not joint.

          (e)  Notwithstanding any other provision of this Section 6, in no
event shall any (i) Investor be required to undertake liability to any person
under this Section 6 for any amounts in excess of the dollar amount of the
proceeds to be received by such Investor from the sale of such Investor's
Registrable Securities (after deducting any fees, discounts and commissions
applicable thereto) pursuant to any Registration Statement under which such
Registrable Securities are to be registered under the Securities Act and (ii)
underwriter be required to undertake liability to any Person hereunder for any
amounts in excess of the aggregate discount, commission or other compensation
payable to such underwriter with respect to the Registrable Securities
underwritten by it and distributed pursuant to the Registration Statement.

          (f)  The obligations of the Company under this Section 6 shall be in
addition to any liability which the Company may otherwise have to any
Indemnified Person and the obligations of any Indemnified Person under this
Section 6 shall be in addition to any liability which such Indemnified Person
may otherwise have to the Company.  The remedies provided in this Section 6 are
not exclusive and shall not limit any rights or remedies which may otherwise be
available to an indemnified party at law or in equity.

          7.   Rule 144

          With a view to making available to the Investors the benefits of Rule
144 under the Securities Act or any other similar rule or regulation of the
Commission that may at any time permit the Investors to sell securities of the
Company to the public without registration ("Rule 144"), the Company agrees to
use its best efforts to:

          (a)  comply with the provisions of paragraph (c) (1) of Rule 144; and

          (b)  file with the Commission in a timely manner all reports and other
documents required to be filed by the Company pursuant to Section 13 or 15(d)
under the Exchange Act; and, if at any time it is not required to file such
reports but in the past had been required to or did file such reports, it will,
upon the request of any Investor, make available other information as required
by, and so long as necessary to permit sales of, its Registrable Securities
pursuant to Rule 144.

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<PAGE>

          8.   Assignment

          The rights to have the Company register Registrable Securities
pursuant to this Agreement shall be automatically assigned by the Investors to
any permitted transferee of all or any portion of such Registrable Securities
(or all or any portion of the Preferred Shares or Warrants of the Company which
is convertible into such securities) only if:  (a) the Investor agrees in
writing with the transferee or assignee to assign such rights, and a copy of
such agreement is furnished to the Company within a reasonable time after such
assignment, (b) the Company is, within a reasonable time after such transfer or
assignment, furnished with written notice of (i) the name and address of such
transferee or assignee and (ii) the securities with respect to which such
registration rights are being transferred or assigned, (c) immediately following
such transfer or assignment, the securities so transferred or assigned to the
transferee or assignee constitute Restricted Securities, and (d) at or before
the time the Company received the written notice contemplated by clause (b) of
this sentence the transferee or assignee agrees in writing with the Company to
be bound by all of the provisions contained herein.

          9.   Amendment and Waiver

          Any provision of this Agreement may be amended and the observance
thereof may be waived (either generally or in a particular instance and either
retroactively or prospectively), only with the written consent of the Company
and Investors who hold a majority-in-interest of the Registrable Securities.
Any amendment or waiver effected in accordance with this Section 9 shall be
binding upon each Investor and the Company.

          10.  Miscellaneous

          (a)  A person or entity shall be deemed to be a holder of Registrable
Securities whenever such person or entity owns of record such Registrable
Securities.  If the Company receives conflicting instructions, notices or
elections from two or more persons or entities with respect to the same
Registrable Securities, the Company shall act upon the basis of instructions,
notice or election received from the registered owner of such Registrable
Securities.

          (b)  If, after the date hereof and prior to the Commission declaring
the Registration Statement to be filed pursuant to Section 2(a) effective under
the Securities Act, the Company grants to any Person any registration rights
with respect to any Company securities which are more favorable to such other
Person than those provided in this Agreement, then the Company forthwith shall
grant (by means of an amendment to this Agreement or otherwise) identical
registration rights to all Investors hereunder.

          (c)  Except as may be otherwise provided herein, any notice or other
communication or delivery required or permitted hereunder shall be in writing
and shall be delivered personally or sent by certified mail, postage prepaid, or
by a nationally recognized overnight courier service, and shall be deemed given
when so delivered personally or by overnight courier service, or, if mailed,
three days after the date of deposit in the United States mails, as follows:

     (i)  if to the Company, to:

                    American TeleSource International, Inc.
                    12500 Network Boulevard, Suite 407
                    San Antonio, Texas 78249
                    (210) 558-6090
                    (210) 558-6095 (Fax)
                    Attention:  H. Douglas Saathoff

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<PAGE>

                    with a copy to:

                    Alice L. King, Esq.
                    Corporate Counsel
                    American TeleSource International, Inc.
                    12500 Network Boulevard, Suite 407
                    San Antonio, Texas 78249
                    (210) 558-6090
                    (210) 558-6095 (Fax)

     (ii)   if to the Initial Investor, to:

                    The Shaar Fund Ltd.,
                    c/o Levinson Capital Management
                    2 World Trade Center, Suite 1820
                    New York, NY 10048
                    Attention:  Samuel Levinson
                    (212) 432-7711
                    (212) 432-7771 (Fax)

                    with a copy to:

                    Cadwalader, Wickersham & Taft
                    100 Maiden Lane
                    New York, NY 10038
                    Attention:  Dennis J. Block, Esq.
                    (212) 504-5555
                    (212) 504-5557 (Fax)

     (iii)  if to any other Investor, at such address as such Investor shall
     have provided in writing to the Company.

The Company, the Initial Investor or any Investor may change the foregoing
address by notice given pursuant to this Section 10(c).

          (d)  Failure of any party to exercise any right or remedy under this
Agreement or otherwise, or delay by a party in exercising such right or remedy,
shall not operate as a waiver thereof.

          (e)  This Agreement shall be governed by and interpreted in accordance
with the laws of the State of New York.  Each of the parties consents to the
jurisdiction of the federal courts whose districts encompass any part of the
City of New York or the state courts of the State of New York sitting in the
City of New York in connection with any dispute arising under this Agreement and
hereby waives, to the maximum extent permitted by law, any objection including
any objection based on forum non conveniens, to the bringing of any such
proceeding in such jurisdictions.

          (f)  The remedies provided in this Agreement are cumulative and not
exclusive of any remedies provided by law.  If any term, provision, covenant or
restriction of this Agreement is held by a court of competent jurisdiction to be
invalid, illegal, void or unenforceable, the remainder of the terms, provisions,
covenants and restrictions set forth herein shall remain in full force and
effect and shall in no way be affected, impaired or invalidated, and the parties
hereto shall use their best efforts to find and employ an alternative means to
achieve the same or substantially the same result as that contemplated by such
term, provision, covenant or restriction.  It is hereby stipulated and declared
to be the intention of the parties that they would have executed the remaining
terms, provisions, covenants and restrictions without including any of such that
may be hereafter declared invalid, illegal, void or unenforceable.

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<PAGE>

          (g)  The Company shall not enter into any agreement with respect to
its securities that is inconsistent with the rights granted to the holders of
Registrable Securities in this Agreement or otherwise conflicts with the
provisions hereof. The Company is not currently a party to any agreement
granting any registration rights with respect to any of its securities to any
person which conflicts with the Company's obligations hereunder or gives any
other party the right to include any securities in any Registration Statement
filed pursuant hereto, except for such rights and conflicts as have been
irrevocably waived. Without limiting the generality of the foregoing, without
the written consent of the holders of a majority in interest of the Registrable
Securities, the Company shall not grant to any person the right to request it to
register any of its securities under the Securities Act unless the rights so
granted are subject in all respect to the prior rights of the holders of
Registrable Securities set forth herein, and are not otherwise in conflict or
inconsistent with the provisions of this Agreement. The restrictions on the
Company's rights to grant registration rights under this paragraph shall
terminate on the date the Registration Statement to be filed pursuant to Section
2(a) is declared effective by the Commission.

          (h)  This Agreement, the Securities Purchase Agreement, the Escrow
Instructions, dated as of a date even herewith (the "Escrow Instructions"),
between the Company, the Initial Investor and Cadwalader, Wickersham & Taft, the
Preferred Shares and the Warrants constitute the entire agreement among the
parties hereto with respect to the subject matter hereof.  There are no
restrictions, promises, warranties or undertakings, other than those set forth
or referred to herein.  This Agreement, the Securities Purchase Agreement, the
Escrow Instructions, the Preferred Shares and the Warrants supersede all prior
agreements and undertakings among the parties hereto with respect to the subject
matter hereof.

          (i)  Subject to the requirements of Section 8 hereof, this Agreement
shall inure to the benefit of and be binding upon the successors and assigns of
each of the parties hereto.

          (j)  All pronouns and any variations thereof refer to the masculine,
feminine or neuter, singular or plural, as the context may require.

          (k)  The headings in this Agreement are for convenience of reference
only and shall not limit or otherwise affect the meaning thereof.

          (1)  The Company acknowledges that any failure by the Company to
perform its obligations under Section 3, or any delay in such performance could
result in direct damages to the Investors and the Company agrees that, in
addition to any other liability the Company may have by reason of any such
failure or delay, the Company shall be liable for all direct damages caused by
such failure or delay.

          (m)  This Agreement may be executed in two or more counterparts, each
of which shall be deemed an original but all of which shall constitute one and
the same agreement.  A facsimile transmission of this signed Agreement shall be
legal and binding on all parties hereto.

                        [NO FURTHER TEXT ON THIS PAGE.]

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<PAGE>

          In Witness Whereof, the parties have caused this Agreement to be duly
executed and delivered as of the date first above written.

                                 American TeleSource International, Inc.

                                 By: /s/ H. Douglas Saathoff
                                    ------------------------------
                                 Name:  H. Douglas Saathoff
                                 Title: Chief Financial Officer

                                 The Shaar Fund Ltd.

                                 By: /s/ Samuel Levinson
                                    ------------------------------
                                 Name:  Samuel Levinson
                                 Title: Managing Director


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