<PAGE>

                                                                   EXHIBIT 10.12

                                                                       EXECUTION
                                                                     COUNTERPART

                                                      EDC LOAN NO. 880-CHIL-7078
                                                         IDB LOAN NO. 1227/0C-CH

================================================================================

              AMENDED AND RESTATED TRANSFER RESTRICTIONS AGREEMENT

                          Dated as of December 22, 1999

                                      among

                                SR TELECOM INC.,

                           SR (BV) HOLDINGS LIMITED,

                              CTR HOLDINGS LIMITED,

                  SERVICIOS RURALES DE TELECOMUNICACIONES S.A.,

                      COMUNICACION Y TELEFONIA RURAL S.A.,

                         EXPORT DEVELOPMENT CORPORATION

                                       and

                         INTER-AMERICAN DEVELOPMENT BANK

================================================================================

<PAGE>

         AMENDED AND RESTATED TRANSFER RESTRICTIONS AGREEMENT (this
"Agreement"), dated as of December 22, 1999, among SR Telecom Inc., a
corporation incorporated under the laws of Canada; SR (BV) Holdings Limited, a
limited liability company incorporated under the laws of the British Virgin
Islands; CTR Holdings Limited, a limited liability company incorporated under
the laws of the British Virgin Islands; Servicios Rurales de Telecomunicaciones
S.A., a sociedad anonima incorporated under the laws of Chile and Comunicacion y
Telefonia Rural S.A., a sociedad anonima incorporated under the laws of Chile
(each an "SRT Party" and collectively the "SRT Parties"), EXPORT DEVELOPMENT
CORPORATION, a corporation established by an Act of the Parliament of Canada
("EDC") and INTER-AMERICAN DEVELOPMENT BANK, an international organization
established by the Articles of Agreement among its member countries ("IDB",
together with EDC, the "Senior Lenders").

                              W I T N E S S E T H :

WHEREAS, SRT owns all of the issued and outstanding shares in the capital stock
of SR (BV) Holdings Limited ("SR (BV) Holdings");

WHEREAS, SR (BV) Holdings owns all of the issued and outstanding shares in the
capital stock of CTR Holdings Limited ("BVI Holdco");

WHEREAS SR (BV) Holdings and BVI Holdco collectively own all of the issued and
outstanding shares in the capital stock of Servicios Rurales de
Telecomunicaciones S.A. ("Chilean Holdco");

WHEREAS Chilean Holdco and BVI Holdco collectively own all of the issued and
outstanding shares in the capital stock of Comunicacion y Telefonia Rural S.A.
(the "Borrower");

WHEREAS, the Borrower has undertaken to design, construct, install and operate a
rural telecommunications network in nine primary zones of Chile (the "Project");

WHEREAS, in order to finance a portion of the Project, the Borrower and EDC are
parties to an Amended and Restated Loan Agreement dated as of the date hereof
(the "EDC Loan Agreement"), providing, subject to the terms and conditions
thereof, for a loan to be made by EDC to the Borrower in an aggregate amount not
exceeding $25,000,000;

WHEREAS, in order to finance a portion of the Project, the Borrower and IDB are
parties to a Loan Agreement dated as of the date hereof ( the "IDB Loan
Agreement," together with the EDC Loan Agreement, the "Senior Loan Agreements"),
providing, subject to the terms and conditions thereof, for a loan to be made by
IDB to the Borrower in an aggregate amount not exceeding $25,000,000;

WHEREAS, the Borrower and the Senior Lenders are parties to a Common Agreement
dated as of the date hereof (the "Common Agreement");

                         TRANSFER RESTRICTIONS AGREEMENT

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                                      - 3 -

NOW, THEREFORE, to induce the Senior Lenders to enter into the Senior Loan
Agreements and extend credit thereunder, and for other good and valuable
consideration, the receipt and sufficiency of which are hereby acknowledged, the
SRT Parties have, inter alia, entered into this Agreement with the Senior
Lenders to undertake certain obligations for the benefit of the Senior Lenders,
and accordingly, the parties hereto agree as follows:

                                    ARTICLE I

                                     GENERAL

         1.01     Definitions. Each capitalized term used herein (including in
the preamble and recitals hereto) and not otherwise defined herein shall have
the meaning assigned to that term in Appendix A to the Amended and Restated
Direct Agreement dated as of the date hereof (the "Direct Agreement") among the
Senior Lenders, the Borrower and SRT.

         1.02     Interpretation. The rules of interpretation set out in the
Direct Agreement shall apply mutatis mutandis to this Agreement as if set forth
in full in this Section 1.02.

                                   ARTICLE II

                             COVENANTS ON TRANSFERS

         2.01     Transfers of Interests. Except for the grant of security
interests in favor of the Senior Lenders under or pursuant to the Security
Documents, each SRT Party agrees not to effect or permit and agrees to cause any
of its Subsidiaries not to effect or permit, without the prior written consent
of the Senior Lenders (such consent not to be unreasonably withheld), any
transfer, assignment, pledge, sale or other disposition or encumbrance (whether
directly or indirectly, including but not limited to, with respect to an
intermediate holding company) of capital stock (or any other option, security or
other interest in any of the foregoing that may be converted into such an equity
interest) of any Transaction Party owned by it (save and except capital stock of
SRT itself), in one or more transactions (collectively, "Transfer"), unless,
immediately after giving effect to such Transfer (and any previous Transfers),
SRT shall own or hold indirectly at least 80% of the aggregate outstanding
capital stock (or any other option, security or other interest in any of the
foregoing that may be converted into such an equity interest) of the Borrower.

         2.02     Assumption of Obligations. No Transfer under Section 2.01
shall be effective unless the transferee thereof assumes in writing all of the
obligations of the transferor under this Agreement and each other Transaction
Document to which such transferor is a party.

         2.03     Notice and Request for Consent. In the event that an SRT Party
wishes to effect a Transfer (whether or not the consent of the Senior Lenders is
required for such Transfer), the SRT Party proposing to effect such Transfer
shall notify each Senior Lender at least 60 days in advance of such proposed
Transfer, which notice shall state in reasonable detail the terms and conditions
of the proposed Transfer, including the identity of the proposed transferee and,
if applicable, of the ultimate beneficial owner thereof, the date upon which the
Transfer is proposed

                         TRANSFER RESTRICTIONS AGREEMENT

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                                      - 4 -

to be made, and any other information any Senior Lender may reasonably request.
With respect to any Transfer which requires the consent of the Senior Lenders,
if the Senior Lenders do not respond to such notice within such 60 days, the
Senior Lenders shall be deemed to have rejected such proposed Transfer. If the
Senior Lenders consent to such Transfer, the SRT Party proposing to effect such
Transfer shall promptly notify each Senior Lender upon the consummation of such
Transfer (and assumption of obligations required by Section 2.02 hereof).

         2.04     Involuntary Transfers. Transfers not permitted by or pursuant
to this Agreement and which result from any action by any Person, other than an
SRT Party or its successors and/or assigns, shall not constitute a breach of the
obligations of such SRT Party hereunder unless 90 days have passed from the date
of such Transfer and such Transfer has not been reversed. The relevant SRT Party
or, as the case may be, its successors and assigns, shall give prompt written
notice to each Senior Lender of any such involuntary Transfer.

         2.05     Effect on Security Interests. Notwithstanding the foregoing,
no Transfer shall be permitted, made or effective (a) if such Transfer would
reasonably be expected to have a material adverse effect upon (i) the security
interests created or purported to be created in favor of the Senior Lenders by
or pursuant to the Security Documents in any of the collateral described therein
held by the Senior Lenders, or (ii) the rights of the Senior Lenders of whatever
nature under any existing Transaction Document, (b) if such Transfer has not
been approved by the Senior Lenders and the consent of the Senior Lenders was
required for such Transfer, (c) unless the Senior Lenders have received from
appropriate legal representatives of the relevant SRT Party a certificate or
opinion relating to the absence of the material adverse effect referred to in
this Section 2.05(a), and (d) unless the proposed transferee first grants a
security interest to the Senior Lenders in the capital stock of the relevant SRT
Party's affiliate or other equity interest so transferred pursuant to the
security documents to be executed to that effect. The granting of the security
interests contemplated in this Section 2.05(d) shall be in form and substance
acceptable to the Senior Lenders, and shall be accompanied by a legal opinion of
counsel to the proposed transferee (in form and substance acceptable to the
Senior Lenders) to the effect that such security interests are valid and
perfected security interests.

                                   ARTICLE III

                   REPRESENTATIONS, WARRANTIES AND COVENANTS

         3.01     Representations and Warranties of SRT. SRT confirms to the
Senior Lenders as of the date hereof each of the representations and warranties
made by SRT in Section 4 of the Direct Agreement, which representations and
warranties are incorporated herein by reference as if fully set forth in this
Agreement.

         3.02     Representations and Warranties of each SRT Party other than
SRT. Each SRT Party, other than SRT, represents and warrants to the Senior
Lenders that, as of the date hereof:

(a)      Organization. It is duly incorporated and validly existing in good
         standing in its jurisdiction of incorporation and is qualified to do
         business in all jurisdictions where such qualification is required
         except where the failure to be so qualified would not reasonably

                         TRANSFER RESTRICTIONS AGREEMENT

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                                      - 5 -

         be expected to have a material adverse effect on its ability to perform
         its obligations hereunder;

(b)      Authority. It has full power and authority to execute and deliver, and
         to incur and perform its obligations under, this Agreement and each
         other Transaction Document to which it is a party;

(c)      Enforceability. Each Transaction Document to which it is a party has
         been duly authorized, executed and delivered by it and constitutes its
         valid and legally binding obligation enforceable against it in
         accordance with its respective terms, except to the extent specified in
         the relevant legal opinions to be delivered on the first disbursement
         of the loans contemplated in the IDB Loan Agreement;

(d)      Governmental Approvals. It has received or has the benefit of all
         authorizations, consents or approvals from governmental authorities
         which are necessary for it to execute and deliver, and to incur and
         perform its obligations under, this Agreement and each other
         Transaction Document to which it is a party, and such authorizations,
         consents or approvals are in full force and effect;

(e)      No Immunity. Neither it nor any of its assets are entitled to any
         immunity from jurisdiction of any court or from legal process (whether
         through service, notice, attachment prior to judgment, attachment in
         aid of execution, execution or otherwise);

(f)      No Legal Proceedings. Except as disclosed to the Senior Lenders, there
         are no actions, suits or proceedings pending or, to the best of its
         knowledge, threatened against or affecting any of its properties in any
         court, before or by any governmental department, board, agency,
         administration or instrumentality or before any arbitrator, and no
         existing default by it under any applicable order, writ, injunction,
         decree or other decision of any court, governmental department, board
         agency, administrator or instrumentality or any arbitrator, in each
         case (i) which could reasonably be expected to have a material adverse
         effect on its ability to perform its obligations under this Agreement,
         or (ii) which could reasonably be expected to render this Agreement
         unenforceable (except to the extent specified in paragraph (c) above);

(g)      No Conflicts. There is no provision of any law, statute, regulation,
         rule, order, injunction, decree, writ or judgment, no provision of its
         certificate of incorporation, bylaws or other constituent document and
         no provision of any mortgage, indenture contract or other agreement to
         which it is a party or affecting its properties which would prohibit,
         conflict with or in any way prevent the execution and delivery of, or
         performance of its obligation under, this Agreement, including, without
         limitation, Sections 4.04 and 4.05, or each other Transaction Document
         to which it is a party; and

(h)      Subordinated Indebtedness. No Subordinated Indebtedness of the Borrower
         is held by it.

         3.03     Representations and Warranties of each SRT Party. Each SRT
Party represents and warrants to the Senior Lenders, that, as of the date
hereof, the chain of ownership described in the first four recitals to this
Agreement is true and accurate in all respects and, subject to the security
interests purported to be created by or under the Security Documents, it has
good

                         TRANSFER RESTRICTIONS AGREEMENT

<PAGE>

                                      - 6 -

marketable title to all of the shares of capital stock of its directly-held
Subsidiaries which it purports to hold, free of any liens other than the ones
permitted under the Common Agreement. The Security Documents create in favor of
the Senior Lenders each security interest purported to be created thereunder,
and except as noted in the legal opinions to be delivered on the first
disbursement of the loans contemplated in the IDB Loan Agreement, each such
security interest is valid and legally binding and will constitute, under
applicable law, fully perfected first and prior security interests enforceable
against the grantor of such security interest, any trustee in any bankruptcy and
any attaching creditor or third party.

                                   ARTICLE IV

                                 MISCELLANEOUS

         4.01     Termination. This Agreement shall terminate on the date on
which (i) all of the Commitments have been reduced to zero or have expired; and
(ii) all of the Borrower's obligations under the Senior Loan Agreements are
indefeasibly paid in full. Upon the termination of this Agreement, the
obligations of the parties hereto shall terminate.

         4.02     Severability. If any provision of this Agreement 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.
If any provisions of this Agreement shall be invalid, illegal or unenforceable
in any jurisdiction, the validity, legality and enforceability of such provision
shall not in any way be affected or impaired in any other jurisdiction thereby.

         4.03     Notices. Any notice, claim, request, demand, consent
designation, direction, instruction, certificate, report or other communication
to be given hereunder shall be given in writing in the English language (or
accompanied by an accurate English language translation upon which the recipient
shall have the right to rely for all purposes) and will be deemed duly given
when (i) personally delivered, (ii) sent by facsimile transmission (but only if,
immediately after the transmission, the sender's facsimile machine records in
writing the correct answer back) or (iii) ten days have elapsed after mailing by
certified or registered mail, postage prepaid, in each case addressed to a party
at its address or facsimile transmission number as set forth below or to another
address or facsimile number of which that party has given notice. Notice of
address or facsimile number change shall be effective only upon receipt.

                  If to ANY SRT PARTY:

                  8150 Trans Canada Highway
                  St. Laurent, Quebec
                  Canada H4S 1M5
                  Attention:  President & CEO
                  Telecopier: 514-335-2035

                         TRANSFER RESTRICTIONS AGREEMENT

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                                      - 7 -

                  If to SENIOR LENDERS:

                  EDC
                  151 O'Connor Street
                  Ottawa, Ontario
                  Canada KlA 1K3
                  Attention:  Loans Operations
                  Telecopier: 613-598-2514

                  and

                  Private Sector Department
                  Inter-American Development Bank
                  1300 New York Avenue, N.W., Washington, D.C. 20577
                  Attention: Loan Administration Unit
                  Telecopier: 202-623-3639

         4.04     GOVERNING LAW. THIS AGREEMENT SHALL BE GOVERNED BY, AND
CONSTRUED IN ACCORDANCE WITH, THE LAWS OF THE STATE OF NEW YORK.

         4.05     Jurisdiction, Service of Process and Venue.

(a)      Submission to Jurisdiction. Each SRT Party hereby agrees that any suit,
         action or proceeding with respect to this Agreement or any judgment
         entered by any court in respect thereof may be brought by the Senior
         Lenders in the courts of the Province of Ontario, Canada or in the
         United States District Court for the Southern District of New York, in
         the Supreme Court of the State of New York sitting in New York County
         (including its Appellate Division) or in any other appellate court in
         the State of New York, as the party commencing such suit, action or
         proceeding may elect in its sole discretion; and each SRT Party hereby
         irrevocably submits to the jurisdiction of such courts for the purpose
         of any such suit, action, proceeding or judgment. Each SRT Party
         further submits, for the purpose of any such suit, action, proceeding
         or judgment brought or rendered against it, to the appropriate courts
         of the jurisdiction of its domicile.

(b)      Service of Process. Each SRT Party, other than SRT and the Borrower,
         hereby agrees that service of all writs, process and summonses in any
         such suit, action or proceeding brought in (i) the Province of Ontario
         may be made upon SRT, presently located at the address noted in Section
         4.03 (the "Canadian Process Agent") or (ii) the State of New York may
         be made upon CT Corporation, presently located at 111 Eighth Avenue,
         13th Floor, New York. New York 10011. USA. (the "US Process Agent" and,
         together with the Canadian Process Agent, the "Process Agents"), and
         each SRT Party, other than SRT and the Borrower, hereby confirms and
         agrees that the Process Agents have been duly and irrevocably appointed
         as its agent and true and lawful attorney-in-fact in its name, place
         and stead to accept such service of any and all such writs, process and
         summonses, and agrees that the failure of the Process Agents to give
         any notice of any such service of process to such SRT Party shall not
         impair or affect the validity of such service or of any judgment based
         thereon. Each SRT Party, other than the Borrower and Chilean Holdco,

                         TRANSFER RESTRICTIONS AGREEMENT

<PAGE>

                                      - 8 -

         hereby further irrevocably consents to the service of process in any
         suit, action or proceeding in said courts by the mailing thereof by the
         Senior Lenders by registered or certified mail, postage prepaid, at its
         address set forth beneath its signature hereto.

(c)      No Limitation on Service of Process. Nothing herein shall in any way be
         deemed to limit the ability of the Senior Lenders to serve any such
         writs, process or summonses in any other manner permitted by applicable
         law or to obtain jurisdiction over any SRT Party in such other
         jurisdictions, and in such manner, as may be permitted by applicable
         law.

(d)      Venue and Forum. Each SRT Party, hereby irrevocably waives any
         objection that it may now or hereafter have to the laying of the venue
         of any suit, action or proceeding arising out of or relating to this
         Agreement or any other Transaction Document brought in the courts of
         the Province of Ontario, Canada or in the Supreme Court of the State of
         New York, County of New York or in the United States District Court for
         the Southern District of New York, and hereby further irrevocably
         waives any claim that any such suit, action or proceeding brought in
         any such court has been brought in an inconvenient forum.

(e)      Acceptance by Process Agent. Each SRT Party other than SRT and the
         Borrower, hereby agrees to cause each Process Agent to execute and
         deliver to the Senior Lenders a letter from each Process Agent in form
         and content acceptable to the Senior Lenders, acting reasonably.

         4.06     WAIVER OF JURY TRIAL, (a) EACH PARTY HERETO HEREBY IRREVOCABLY
WAIVES, TO THE FULLEST EXTENT PERMITTED BY APPLICABLE LAW, ANY AND ALL RIGHT TO
TRIAL BY JURY IN ANY LEGAL PROCEEDING ARISING OUT OF OR RELATING TO THIS
AGREEMENT OR THE TRANSACTIONS CONTEMPLATED HEREBY.

         (b) Each SRT Party hereby acknowledges that IDB shall be entitled under
applicable law, including the provisions of the International Organizations
Immunities Act, to immunity from a trial by jury in any action, suit or
proceeding arising out of or relating to this Agreement, any other Transaction
Document or the transactions contemplated hereby or any other agreement to which
any SRT Party is a party, brought against IDB in any court of the United States
of America. To the maximum extent not prohibited by law, each of the SRT
Parties, EDC and IDB hereby irrevocably and unconditionally waives trial by jury
in any legal action or proceeding relating to this Agreement or any Transaction
Document to which such person is a party and for any counterclaim therein in any
forum in which IDB is not entitled to immunity from a trial by jury. To the
extent that any SRT Party has or hereafter may acquire any immunity (sovereign
or otherwise) from any legal action, suit or proceeding, from jurisdiction of
any court or from set-off or any legal process (whether service or notice,
attachment prior to judgment, attachment in aid of execution of judgment,
execution of judgment or otherwise) with respect to itself or any of its
property, each SRT Party hereby irrevocably waives and agrees not to plead or
claim such immunity in respect of its obligations under this Agreement and the
other Transaction Documents. Each SRT Party agrees that the waivers set forth
above shall have the fullest extent permitted under the Foreign Sovereign
Immunities Act of 1976 of the United States of America and are intended to be
irrevocable and not subject to withdrawal for purposes of such Act.

                         TRANSFER RESTRICTIONS AGREEMENT

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                                      - 9 -

         4.07     Amendments. This Agreement may be amended only by an agreement
in writing executed by each of the parties hereto.

         4.08     Expenses. The SRT Parties are jointly and severally liable for
all out-of-pocket expenses of the Senior Lenders (including the reasonable fees
and expenses of counsel for the Senior Lenders) incurred in connection with the
enforcement of this Agreement.

         4.09     Benefits of Agreement. Nothing in this Agreement, express or
implied, shall give to any Person, other than the parties hereto and their
successors and permitted assigns hereunder and under Financing Document, any
benefit or any legal or equitable right or remedy under this Agreement.

         4.10     Remedies. No remedy herein conferred upon the Senior Lenders
is intended to be exclusive of any other remedy and each and every such other
remedy shall be cumulative and shall be in addition to every other remedy given
hereunder or now or hereafter existing at law or in equity or by statute or
otherwise.

         4.11     Effectiveness. This Agreement shall come into full force and
effect, and amend and restate, the Transfer Restrictions Agreement dated as of
April 13, 1999 among the SRT Parties and EDC as of the date on which the EDC
Loan Agreement becomes effective in accordance with Section 6 thereof.

         4.12     Counterparts. This Agreement may be executed in two or more
counterparts, each of which shall be deemed to be an original but all of which
together shall constitute one and the same instrument.

         4.13     Headings. The headings in this Agreement are for convenience
of reference only and shall not limit or otherwise affect any of the terms
hereof.

         4.14     Use of English Language. This Agreement has been negotiated
and executed in the English language. All certificates, reports, notices and
other documents and communications given or delivered pursuant to this Agreement
(including, without limitation, any modifications or supplements hereto) shall
be in the English language, or accompanied by a certified English translation
thereof. Except in the case of laws or official communications of Chile, in the
case of any document originally issued in a language other than English, the
English language version of any such document shall for purposes of this
Agreement, and absent manifest error, control the meaning of the matters set
forth therein.

                        TRANSFER RESTRICTIONS AGREEMENT

<PAGE>

                                     - 10 -

                  IN WITNESS WHEREOF, the parties hereto, by their officers duly
authorized, have caused this Agreement to be duly executed and delivered as of
the date first above written.

                                    SR TELECOM INC.

                                    By: /s/ W. Ronald Couchman
                                        ----------------------------
                                    Name:  W. Ronald Couchman
                                    Title: Chief Executive Officer

                                    BY: /s/ David L. Adams
                                        ----------------------------
                                    Name:  David L. Adams
                                    Title: Chief Financial Officer

                        TRANSFER RESTRICTIONS AGREEMENT

<PAGE>

                                     - 11 -

                                    SR (BV) HOLDINGS LIMITED

                                    By: /s/ W. Ronald Couchman
                                        -----------------------------
                                    Name:  W. Ronald Couchman
                                    Title: Director

                                    By:______________________________
                                    Name:
                                    Title:

                        TRANSFER RESTRICTIONS AGREEMENT

<PAGE>

                                     - 12 -

                              CTR HOLDINGS LIMITED

                              By: /s/ W. Ronald Couchman
                                  -----------------------------
                              Name:  W. Ronald Couchman
                              Title: Director

                              By:_____________________________
                              Name:
                              Title:

                         TRANSFER RESTRICTIONS AGREEMENT

<PAGE>

                                     - 13 -

                              SERVICIOS RURALES DE
                              TELECOMUNICACIONES S.A.

                              By: /s/ W. Ronald Couchman
                                  ------------------------------
                              Name:  W. Ronald Couchman
                              Title: Director

                              By:________________________________
                              Name:
                              Title:

                        TRANSFER RESTRICTIONS AGREEMENT

<PAGE>

                                     - 14 -

                              COMUNICACION Y TELEFONIA RURAL S.A.

                              By: /s/ D'Arcy J. Leddy
                                  -------------------------------
                              Name:  D'Arcy J. Leddy
                              Title: Director

                        TRANSFER RESTRICTIONS AGREEMENT

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                                     - 15 -

                              EXPORT DEVELOPMENT CORPORATION

                              By: /s/ Bruce Dunlop
                                  --------------------------------
                              Name:  Bruce Dunlop
                              Title: Financial Services Manager

                              By: /s/ Brian Craig
                                  --------------------------------
                              Name:  Brian Craig
                              Title: Financial Services Manager

                         TRANSFER RESTRICTIONS AGREEMENT

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                                     - 16 -

                              INTER-AMERICAN DEVELOPMENT BANK

                              By: /s/ Bernardo Frydman
                                  -------------------------------
                              Name:  Bernardo Frydman
                              Title: Deputy Manager, Private Sector Department

                        TRANSFER RESTRICTIONS AGREEMENT