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                                                                    EXHIBIT 10.9

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                   SECURITIES SALE AND CONTRIBUTION AGREEMENT

                           dated as of June 30, 2004

                                    between

                      THORNBURG MORTGAGE DEPOSITOR, L.L.C.

                                      and

                            THORNBURG MORTGAGE, INC.

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                                TABLE OF CONTENTS

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ARTICLE I    DEFINITIONS and OTHER MATTERS
     SECTION 1.1   Eligible Securities ........................................   1
     SECTION 1.2   Terms Defined in Schedule 1.01 .............................   2
     SECTION 1.3   Accounting and UCC Terms ...................................   2
     SECTION 1.4   Computation of Time Periods ................................   2
     SECTION 1.5   Reference to this Agreement ................................   2
ARTICLE II   SALE OF SECURITIES; delivery of securities, payment or depositor
             purchase price
     SECTION 2.1   Sale of Securities .........................................   2
     SECTION 2.2   Delivery of Eligible Securities ............................   3
     SECTION 2.3   Determination of Depositor Purchase Price ..................   4
     SECTION 2.4   Purchase Commitment Term ...................................   4
     SECTION 2.5   Capital Contribution .......................................   4
ARTICLE III  REPRESENTATIONS AND WARRANTIES; REMEDIES AND
             BREACH
     SECTION 3.1   Representations and Warranties of the Seller ...............   4
     SECTION 3.2   Representations and Warranties and Other Rights Regarding
                   Individual Eligible Securities .............................   7
     SECTION 3.3   Remedies for Breach of Representations and Warranties ......   7
     SECTION 3.4   Conditions to Each Closing .................................   8
     SECTION 3.5   Covenant of the Seller .....................................   8
     SECTION 3.6   Representations and Warranties of the Depositor ............   8
ARTICLE IV   MISCELLANEOUS PROVISIONS
     SECTION 4.1   Amendment ..................................................   9
     SECTION 4.2   Governing Law ..............................................  10
     SECTION 4.3   Duration of Agreement ......................................  10
     SECTION 4.4   Notices ....................................................  10
     SECTION 4.5   Severability of Provisions .................................  11
     SECTION 4.6   Relationship of Parties ....................................  11
     SECTION 4.7   Execution in Counterparts ..................................  11
     SECTION 4.8   Non-Petition Agreement .....................................  12
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                                      -i-
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                               TABLE OF CONTENTS
                                    (CONT'D)

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     SECTION 4.9   No Recourse ................................................  12
     SECTION 4.10  Survival ...................................................  13
ARTICLE V    ASSIGNMENT
     SECTION 5.1   Successors and Assigns; Assignment of Securities Sale and
                   Contribution Agreement .....................................  13
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EXHIBIT A FORM OF TRANSFER SUPPLEMENT

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                   SECURITIES SALE AND CONTRIBUTION AGREEMENT

      SECURITIES SALE AND CONTRIBUTION AGREEMENT, dated as of June 30, 2004 (as
amended, supplemented or otherwise modified and in effect from time to time, the
"Securities Sale and Contribution Agreement"), between THORNBURG MORTGAGE
DEPOSITOR, L.L.C., a Delaware limited liability company, as purchaser (the
"Depositor"), and THORNBURG MORTGAGE, INC., a Maryland corporation
("Thornburg"), as seller (in such capacity, the "Seller").

                               W I T N E S S E T H

      WHEREAS, the Seller owns 100% of the Depositor's outstanding membership
interest;

      WHEREAS, the Seller owns Eligible Securities;

      WHEREAS, the Depositor has agreed to purchase from the Seller and the
Seller has agreed to sell to the Depositor from time to time Eligible Securities
until the termination of this Securities Sale and Contribution Agreement;

      WHEREAS, the Depositor and the Seller wish to prescribe the manner of
purchase of Eligible Securities;

      WHEREAS, the Depositor intends to transfer Eligible Securities to the
Issuer from time to time pursuant to Repo Agreements;

      NOW, THEREFORE, for good and valuable consideration the receipt and
sufficiency of which is hereby acknowledged, the Depositor and the Seller agree
as follows:

                                    ARTICLE I
                          DEFINITIONS AND OTHER MATTERS

      SECTION 1.1 Eligible Securities. As used in herein, "Eligible Securities"
means securities that (A) with respect to Agency Securities, (i) are direct
obligations of, or that are fully guaranteed as to principal and interest by,
any Agency, (ii) are either ARM 1-1 (fully indexed), ARM 1-1 (non-fully
indexed), ARM 3-1, or ARM 5-1, Securities, (iii) on the date of sale thereof by
the Depositor to the Issuer pursuant to any related Eligible Repo Agreement,
satisfy each of the eligibility requirements therefor set forth in the Issuer's
Investment Policy on such date, and (iv) on the date of acquisition thereof by
the Depositor pursuant to the Securities Sale and Contribution Agreement,
conform to all representations and warranties made by the Seller or Depositor
with respect thereto in the Securities Sale and Contribution Agreement or the
related Repo Agreement, as applicable, and (B) with respect to Private Label
Securities, (i) are rated in the top long-term rating category by at least one
of Fitch, Moody's or S&P, and not rated below the top long-term rating category
by any of Fitch, Moody's or S&P (ii) are either Private Label ARM 1-1 (fully
indexed), Private Label ARM 1-1 (non-fully indexed), Private Label ARM 3-1, or
Private Label ARM 5-1 Securities, (iii) on the date of sale thereof by the
Depositor to the Issuer pursuant to any related Eligible Repo Agreement, satisfy
each of the eligibility requirements therefor set forth in the Issuer's
Investment Policy on such date, (iv) are backed by a Prime Residential Mortgage
Loan Pool with a weighted average FICO Score (weighted on the

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initial unpaid principal balance of each mortgage loan on the date each such
security is issued and the FICO Score of each mortgagor at the origination of
the related mortgage loan) greater than 640, and (v) on the date of acquisition
thereof by the Depositor pursuant to the Securities Sale and Contribution
Agreement, conform to all representations and warranties made by the Seller or
the Depositor with respect thereto in the Securities Sale and Contribution
Agreement or the related Repo Agreement, as applicable.

      SECTION 1.2 Terms Defined in Schedule 1.01. As used herein, unless
otherwise defined herein, capitalized terms defined in Schedule 1.01 attached to
the Administration Agreement, dated as of June 30, 2004, between the Issuer and
Thornburg, as Administrator (and any successors and permitted assigns of
Thornburg, as such Schedule 1.01 may be amended, supplemented or otherwise
modified from time to time (the "Administration Agreement"), shall have the
respective meanings specified therein.

      SECTION 1.3 Accounting and UCC Terms. As used herein, unless otherwise
specifically defined, and unless the context requires a different meaning:

            (a)   all accounting terms shall be construed in accordance with
United States generally accepted accounting principles; and

            (b)   all terms defined in Article 9 of the UCC as in effect in the
State of New York on the date hereof are used herein as so defined.

      SECTION 1.4 Computation of Time Periods. Unless otherwise stated in this
Securities Sale and Contribution Agreement, in the computation of a period of
time from a specified date to a later specified date, the word "from" means
"from and including" and the words "to" and "until" each means "to but
excluding".

      SECTION 1.5 Reference to this Agreement. The words "hereof", "herein" and
"hereunder" and words of similar import when used in this Securities Sale and
Contribution Agreement shall refer to this Securities Sale and Contribution
Agreement as a whole and not to any particular provision of this Securities Sale
and Contribution Agreement. Unless otherwise specified, references in this
Securities Sale and Contribution Agreement to any Section are references to such
Section of this Securities Sale and Contribution Agreement, and references in
any Section or definition to any subsection or clause are references to such
subsection or clause of such Section or definition.

                                   ARTICLE II
              SALE OF SECURITIES; DELIVERY OF SECURITIES, PAYMENT
                          OR DEPOSITOR PURCHASE PRICE

      SECTION 2.1 Sale of Securities.

            (a)   From time to time, pursuant to any Transfer Supplement, the
Seller may sell, transfer, assign, set over and convey to the Depositor and the
Depositor shall purchase, without recourse, but subject to the terms hereof and
except as otherwise provided herein, all the right, title and interest of the
Seller in and to each Eligible Security identified on the Transfer Supplement;
provided, however, that the Depositor shall not be required to purchase Eligible

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Securities on any Closing Date having an aggregate Depositor Purchase Price
greater than the amount of cash which is received on the applicable Closing Date
under one or more related Repo Agreements pursuant to which the Depositor
transfers such Eligible Securities to the Issuer, unless the Seller shall agree
to contribute to the Depositor as a capital contribution any such excess of the
aggregate Depositor Purchase Price of such Portfolio of Eligible Securities over
the amount of cash paid to the Depositor by the Issuer under one or related Repo
Agreements on such Closing Date; provided, further, that each Security
transferred on each Closing Date must be an Eligible Security. The Seller shall
provide a notice to the Depositor, the Issuing and Paying Agent, the
Administrator, the Collateral Agent and the Issuer not later than 10:00 a.m. New
York City time on any Closing Date of its intention to sell a Portfolio to the
Depositor pursuant to a Transfer Supplement; provided, however, that the Seller
may deliver such notice to the Depositor, the Issuing and Paying Agent, the
Administrator, the Collateral Agent and the Issuer at any time prior to 2:00
p.m. Eastern Time on any Closing Date if the Issuer will not issue additional
Secured Liquidity Notes to fund its purchase of the applicable Portfolio from
the Depositor on such Closing Date. In such notice, the Seller shall inform the
Depositor of the aggregate PAR Value, the Group, and the Depositor Purchase
Price of the Eligible Securities that it intends to sell on such date. Each
Transfer Supplement shall be executed by the Seller and the Depositor at the
time of the sale of the subject Portfolio.

            (b)   Upon execution of any Transfer Supplement by the Seller and
the Depositor and receipt by the Seller of the Depositor Purchase Price for each
of the Eligible Securities identified on such Transfer Supplement, the Seller
hereby sells, assigns, transfers, sets over and conveys to the Depositor all of
the Seller's right, title and interest in, to and under each such Eligible
Security. It is intended that each transfer, assignment and conveyance herein
contemplated constitutes a sale of the applicable Eligible Securities, conveying
good title thereto free and clear of any liens, by the Seller to the Depositor
and not a loan secured by such Eligible Securities and that the Eligible
Securities not be part of the Seller's estate in the event of insolvency. In the
event that any Eligible Securities are held to be property of the Seller or if
for any other reason any Transfer Supplement is held or deemed to create a
security interest in (and not a sale of) the related Eligible Securities, the
parties intend that the Seller shall be deemed to have granted, and does hereby
grant, to the Depositor a first priority perfected security interest in such
Eligible Securities and all collateral related thereto now existing or hereafter
arising for the purpose of securing the rights of the Depositor under this
Securities Sale and Contribution Agreement, and that this Securities Sale and
Contribution Agreement and each Transfer Supplement shall each constitute a
security agreement under applicable law.

            (c)   It is expressly understood and agreed that the Seller shall
not have any obligation to transfer any Securities to the Depositor, and any
such transfer by the Seller shall be made in its sole and absolute discretion.

      SECTION 2.2 Delivery of Eligible Securities.

      All Eligible Securities sold by the Seller to the Depositor hereunder
shall be transferred to the Depositor by causing such Eligible Securities to be
credited to the Issuer Account, maintained with and under the control of the
Collateral Agent, in the name of the Issuer in accordance with the Security
Agreement, the Administration Agreement and the Securities Account Control
Agreement on the related Closing Date.

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      SECTION 2.3 Determination of Depositor Purchase Price.

      On each Closing Date, the Seller shall deliver to the Depositor a Transfer
Supplement, in accordance with Section 2.1, and shall notify the Depositor of
its calculation of the Depositor Purchase Price for each Eligible Security in
the Portfolio. The Depositor and the Seller shall use commercially reasonable
efforts to close the sale of any Portfolio on any such Closing Date. The
Depositor shall pay to the Seller the Depositor Purchase Price of each Eligible
Security purchased by it hereunder (to the extent the Depositor Purchase Price
is not paid in cash, such unpaid portion of the Depositor Purchase Price shall
be deemed a capital contribution in accordance with the terms and conditions as
set forth in Section 2.5 herein) not later than 6:00 p.m. New York City time on
the applicable Closing Date.

      SECTION 2.4 Purchase Commitment Term.

      Subject to the terms and conditions of the Program Documents, the
commitment of the Depositor under this Securities Sale and Contribution
Agreement shall expire upon the Collateral Agent's delivery of Notice of Program
Default to the Seller in accordance with Section 5.1 of the Security Agreement.

      SECTION 2.5 Capital Contribution.

            (a)   Payment of Depositor Purchase Price. On the terms and subject
to the conditions set forth in this Securities Sale and Contribution Agreement
and the other Program Documents, on each Closing Date, the Depositor agrees to
pay to the Seller the aggregate Depositor Purchase Price in respect of the sale
of the Portfolio of Eligible Securities by the Seller to the Depositor to occur
on such Closing Date. Such Depositor Purchase Price shall be paid by the
Depositor to the Seller in the form of cash and/or a capital contribution by the
Seller to the Depositor as follows:

            (i)   First, the Depositor Purchase Price for such Eligible
      Securities shall be paid in cash to the extent that the Depositor has
      received cash from the Issuer on such Closing Date under one or more
      related Repo Agreements pursuant to which the Depositor has transferred
      such Eligible Securities to the Issuer; and

            (ii)  Second, the Seller shall be deemed to have made a contribution
      to the capital of the Depositor in an amount equal to such remaining
      unpaid portion of the Depositor Purchase Price.

      SECTION 2.6 Distributions by the Depositor. The Depositor (I) shall from
time to time make distributions to the Seller, as return on equity, from P&I
Proceeds received and held by the Depositor, to the extent such P&I Proceeds (a)
exceed 10% of the Face Amount of the earliest maturing Class of Secured
Liquidity Notes then outstanding, or (b) together with the amount of any P&I
Proceeds which have been previously applied to the repayment of Secured
Liquidity Notes in the preceding twelve months, exceed 10% of the average
outstanding Face Amount of Secured Liquidity Notes on each Business Day during
such twelve month period, and (II) may from time to time make further
distributions to the Seller from amounts received by the Depositor under the
Program Documents; provided that, in either case, the Depositor shall not make
any distributions to the Seller on any day to the extent the Depositor shall
have failed to

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pay the Issuer any amounts due and owing to the Issuer on or prior to such date
under any Repo Agreement.

                                   ARTICLE III
                        REPRESENTATIONS AND WARRANTIES;
                              REMEDIES AND BREACH

      SECTION 3.1 Representations and Warranties of the Seller.

      The Seller represents and warrants to the Depositor that as of each
applicable Closing Date the following will be true and correct in all material
respects.

            (a)   Due Organization and Authority. The Seller (i) is a
corporation, duly organized, validly existing and in good standing under the
laws of the State of Maryland, and (ii) has all requisite power and authority to
carry on its business as now conducted in all material respects and to perform
its obligations under this Securities Sale and Contribution Agreement.

            (b)   No Conflicts. The execution and delivery of this Securities
Sale and Contribution Agreement by the Seller, and the performance and
compliance with the terms of this Securities Sale and Contribution Agreement by
the Seller, will not violate the Seller's organizational documents or constitute
a default (or an event which, with notice or lapse of time, or both, would
constitute a default) under, or result in the breach of, any material agreement
or other instrument to which it is a party or which is applicable to it or any
of its assets, in each case which, in the Seller's good faith and reasonable
judgment, materially and adversely affects the ability of the Seller to carry
out the transactions contemplated by this Securities Sale and Contribution
Agreement.

            (c)   Due Execution. The Seller has the full power and authority to
enter into and consummate all transactions contemplated by this Securities Sale
and Contribution Agreement, has duly authorized the execution, delivery and
performance of this Securities Sale and Contribution Agreement, and has duly
executed and delivered this Securities Sale and Contribution Agreement.

            (d)   Enforceability. This Securities Sale and Contribution
Agreement, assuming due authorization, execution and delivery by the Depositor,
constitutes a valid, legal and binding obligation of the Seller, enforceable
against the Seller in accordance with the terms hereof, subject to (A)
applicable bankruptcy, insolvency, reorganization, moratorium and other laws
affecting the enforcement of creditors' rights generally, and (B) general
principles of equity, regardless of whether such enforcement is considered in a
proceeding in equity or at law.

            (e)   No Violation. The Seller is not in violation of (and its
execution and delivery of this Securities Sale and Contribution Agreement and
its performance and compliance with the terms of this Securities Sale and
Contribution Agreement will not constitute a violation of) any law, any order or
decree of any court or arbiter, or any order, regulation or demand of any
federal, state or local governmental or regulatory authority, which violation,
in the Seller's good faith and reasonable judgment, is likely to affect
materially and adversely either the ability of the Seller to perform its
obligations under this Securities Sale and Contribution Agreement or the
financial condition of the Seller.

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            (f)   No Litigation. No litigation is pending or, to the Seller's
knowledge, threatened against the Seller the outcome of which, in the Seller's
good faith and reasonable judgment, would reasonably be expected to prohibit the
Seller from entering into this Securities Sale and Contribution Agreement or
materially and adversely affect the ability of the Seller to perform its
obligations under this Securities Sale and Contribution Agreement.

            (g)   No Broker's Fees. The Seller has not dealt with any broker,
investment banker, agent or other person, other than the Issuer, the Depositor,
and each Secured Liquidity Note Dealer, and their respective Affiliates that may
be entitled to any commission or compensation in connection with the sale of
Eligible Securities or the consummation of any of the other transactions
contemplated hereby.

            (h)   No Consents Necessary. No consent, approval, authorization or
order of, registration or filing with, or notice to, any governmental authority
or court is required, under federal or state law (including, with respect to any
bulk sale laws), for the execution, delivery and performance of or compliance by
the Seller with this Securities Sale and Contribution Agreement, or the
consummation by the Seller of any transaction contemplated hereby, other than
(1) the filing or recording of financing statements, instruments of assignment
and other similar documents necessary in connection with the Seller's sale of
Eligible Securities to the Depositor, (2) such consents, approvals,
authorizations, qualifications, registrations, filings or notices as have been
obtained or made and (3) where the lack of such consent, approval,
authorization, qualification, registration, filing or notice would not, in the
Seller's good faith and reasonable judgment, have a material adverse effect on
the performance by the Seller under this Securities Sale and Contribution
Agreement.

            (i)   Ordinary Course of Business. The performance of the
transactions contemplated by this Securities Sale and Contribution Agreement are
in the ordinary course of business of the Seller.

            (j)   No Untrue Information. Neither this Securities Sale and
Contribution Agreement, any Transfer Supplement nor any written statement,
written report or other document prepared by the Seller pursuant to this
Securities Sale and Contribution Agreement or in connection with the
transactions contemplated hereby contains any untrue statement of a material
fact relating to the Seller or the Securities transferred by the Seller to the
Depositor hereunder.

            (k)   Financial Statements. The Seller has delivered to the
Depositor consolidated financial statements as of December 31, 2003 as to its
last three complete fiscal years and any later quarter ended more than sixty
(60) days prior to the execution of this Securities Sale and Contribution
Agreement. All such financial statements fairly present the pertinent results of
operations and changes in financial position at the end of each such period of
the Seller and its subsidiaries and have been prepared pursuant to generally
accepted accounting principles consistently applied throughout the periods
involved, except as set forth in the notes thereto. There has been no change in
the business, operations, financial condition, properties or assets of the
Seller since the date of the Seller's most recently provided financial
statements that would have a material adverse effect on its ability to perform
its obligations under this Securities Sale and Contribution Agreement.

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            (l)   Solvency. The Seller is solvent and its sale of the applicable
Eligible Securities to the Depositor on such date is not undertaken to hinder,
delay or defraud any of the Seller's creditors.

      It is understood and agreed that the representations and warranties set
forth in this Section 3.1 shall survive delivery of the respective Eligible
Securities to the Depositor and any successor thereof and the termination of
this Securities Sale and Contribution Agreement. Upon discovery by any of the
parties hereto of a breach of any of the representations and warranties made
pursuant to and set forth in this Section 3.1 which adversely affects the
interests of the Depositor and which adversely affects the value of the Eligible
Securities or the interests of the Depositor or any of its successors and
assigns, the party discovering such breach shall give prompt written notice to
the other, the Issuing and Paying Agent, the Collateral Agent, the Administrator
and the Issuer.

      SECTION 3.2 Representations and Warranties and Other Rights Regarding
Individual Securities.

      With respect to each Security sold by the Seller to the Depositor, the
Seller hereby represents and warrants to the Depositor (and for the benefit of
the Issuer and the Collateral Agent) that as of the applicable Closing Date:

            (a)   the Seller owns and has good and marketable title to such
Security free and clear of any lien, claim or encumbrance (including any tax
lien or judgment lien) of any entity or person, other than liens which will be
released upon application of such sale;

            (b)   information set forth in the related Transfer Supplement
relating to the sale of such Security is true and correct in all material
respects;

            (c)   no payment under such Security is past its contractual due
date;

            (d)   such Security sold by the Seller pursuant to a Transfer
Supplement was not selected from Securities owned by the Seller in a manner so
as to materially adversely affect the interests of the Depositor and the Issuer,
as applicable;

            (e)   the Seller has received all consents and approvals required by
the terms of such Security to the transfer to the Depositor of its interest and
rights in such Security;

            (f)   the Market Price for such Security is available or obtainable
on such Closing Date in accordance with the Administration Agreement;

            (g)   the Depositor's purchase of such Security, and subsequent
transfer of such Security to the Issuer under any Repo Agreement, shall not
cause a Single Issuer Cap Excess Amount to exist on such date; and

            (h)   such Security is an Eligible Security.

      It is understood and agreed that the representations and warranties set
forth in this Section 3.2 shall survive the sale of each Security to the
Depositor and the termination of this Securities

                                       7
<PAGE>

Sale and Contribution Agreement and shall inure to the benefit of the Issuer and
the Collateral Agent notwithstanding any restrictive or qualified endorsement on
any Security. The Seller hereby consents to and acknowledges the assignment by
the Depositor to the Issuer of the representations and warranties and other
rights set forth in this Section 3.2 and in Section 3.1 hereof and agrees that
the Issuer may enforce any remedies for such breaches directly against the
Seller.

      SECTION 3.3 Remedies for Breach of Representations and Warranties.

      Upon discovery of the Seller or the Depositor of a breach of any of the
representations and warranties or agreements set forth in Sections 3.1 and 3.2
which adversely affects the value of any Security or the interests of the
Depositor or any of its successors and assigns, the party discovering such
breach shall give prompt written notice to the other, the Issuing and Paying
Agent, the Collateral Agent, the Administrator and the Issuer.

      Within one (1) Business Day of the earlier of either discovery by or
notice to the Seller of any breach of a representation or warranty or agreement
set forth in Sections 3.1 and 3.2 hereof which adversely affects the value of
any Security or the interests of the Depositor or any of its successors and
assigns, the Seller shall repurchase such Security at the Repurchase Price. Upon
receipt of the Repurchase Price by the Collateral Agent, the Depositor and the
Seller shall arrange for the reassignment of the Security or Securities to the
Seller.

      If any Security with respect to which the Seller has breached a
representation and warranty set forth in Sections 3.1 and 3.2 herein has been
sold by the Issuer for less than the related Repurchase Price, the Seller shall
pay the Depositor the excess of (x) the Repurchase Price for such Security, over
(y) the proceeds realized by the Issuer in connection with such sale.

      SECTION 3.4 Conditions to Initial Closing; Conditions to Each Closing.

      Schedule 5.05 to the Administration Agreement is hereby incorporated by
reference herein as if the text thereof were set forth in full herein. Further,
the obligation of the Depositor to purchase the Eligible Securities that are the
subject of any Transfer Supplement shall be subject to satisfaction of the
condition that all of the representations and warranties of the Seller contained
in Section 3.1 herein shall be true and correct in all material respects as of
such Closing Date and the representations and warranties of the Seller in
Section 3.2 herein shall be true and correct in all material respects with
respect to the Securities subject to such Transfer Supplement as of such Closing
Date.

      SECTION 3.5 Covenants of the Seller.

            (a)   The Seller shall maintain its qualifications to do business
and all licenses necessary to perform its obligations hereunder except where the
failure to maintain such qualification or license would not have a material
adverse effect on its ability to perform its obligations under this Securities
Sale and Contribution Agreement or on the Securities purchased hereunder.

            (b)   The Seller shall give notice to the Depositor of any amounts
paid or contributed to the Depositor by the Seller which constitute P&I
Proceeds.

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      SECTION 3.6 Representations and Warranties of the Depositor.

      The Depositor represents and warrants to the Seller that as of each
applicable Closing Date:

            (a)   Due Organization. The Depositor is a limited liability company
      duly formed and validly existing under the laws of the State of Delaware;

            (b)   Due Authorization; Enforceability. The Program Documents to
      which the Depositor is a party have been duly authorized, executed and
      delivered by the Depositor and constitute valid and legally binding
      obligations of the Depositor, enforceable against the Depositor in
      accordance with their terms, subject, as to enforcement, to bankruptcy,
      insolvency, reorganization and other similar laws of general applicability
      relating to or affecting creditors' rights and to general equity
      principles, regardless of whether such enforcement is considered in a
      proceeding in equity or at law;

            (c)   No Conflicts. The execution and delivery of the Program
      Documents to which the Depositor is a party by the Depositor and its
      performance of and compliance with the terms of the Program Documents to
      which the Depositor is a party will not violate the Depositor LLC
      Agreement or certificate of formation, and will not conflict with or
      result in a breach of any of the terms or provisions of, or constitute a
      default under, any indenture, mortgage, deed of trust, loan agreement or
      other material agreement or instrument to which the Depositor is a party
      or by which the Depositor or to which any property or assets of the
      Depositor is subject;

            (d)   No Violation. The Depositor is not in violation of (and its
      execution and delivery of this Securities Sale and Contribution Agreement
      and its performance and compliance with the terms of this Securities Sale
      and Contribution Agreement will not constitute a violation of) any law,
      any order or decree of any court or arbiter, or any order, regulation or
      demand of any federal, state or local governmental or regulatory
      authority, which violation is likely to affect materially and adversely
      either the ability of the Depositor to perform its obligations under this
      Securities Sale and Contribution Agreement or the financial condition of
      the Depositor.

            (e)   No Consents Necessary. No consent, approval, authorization or
      order of, registration or filing with, or notice to, any governmental
      authority or court is required, under federal or state law (including,
      with respect to any bulk sale laws), for the execution, delivery and
      performance of or compliance by the Depositor with this Securities Sale
      and Contribution Agreement, or the consummation by the Depositor of any
      transaction contemplated hereby, other than (1) the filing or recording of
      financing statements, instruments of assignment and other similar
      documents necessary in connection with Seller's sale of the Eligible
      Securities to the Depositor, (2) such consents, approvals, authorizations,
      qualifications, registrations, filings or notices as have been obtained or
      made and (3) where the lack of such consent, approval, authorization,
      qualification, registration, filing or notice would not have a material
      adverse effect on the performance by the Depositor under this Securities
      Sale and Contribution Agreement.

                                       9
<PAGE>

            (f)   No Defaults. The Depositor is not in default with respect to
      any order or decree of any court or any order, regulation or demand of any
      federal, state, municipal or governmental agency, which default might have
      consequences that would materially and adversely affect the condition
      (financial or other) or operations of the Depositor or its properties or
      might have consequences that would affect its performance hereunder; and

            (g)   No Litigation. No litigation is pending or, to the Depositor's
      knowledge, threatened against the Depositor which would prohibit its
      entering into this Securities Sale and Contribution Agreement or
      performing its obligations under this Securities Sale and Contribution
      Agreement;

            (h)   Ordinary Course of Business. The performance of the
      transactions contemplated by this Securities Sale and Contribution
      Agreement are in the ordinary course of business of the Depositor; and

            (i)   Solvency. The Depositor is solvent and its purchase of the
      applicable Eligible Securities on such date is not undertaken to hinder,
      delay or defraud any of the Depositor's creditors.

                                   ARTICLE IV
                            MISCELLANEOUS PROVISIONS

      SECTION 4.1 Amendment. Any amendment, modification or supplement to this
Securities Sale and Contribution Agreement shall be in writing signed by the
parties hereto. Except to the extent set forth in the following sentence,
amendments, modifications, or supplements to the Program Documents (including
without limitation this Securities Sale and Contribution Agreement) may be
executed by the parties thereto from time to time without notice to or the
consent of the holders of any Notes for any purpose deemed necessary or
appropriate by the Administrator, including without limitation to provide for
the Issuer to enter into certain Hedge Contracts, to issue callable commercial
paper notes, to modify a Normal OC Percentage or a Required OC Percentage, and
to add to the categories or Groups of Eligible Securities that the Issuer may
purchase and fund through the issuance of Notes; provided, however, that each
amendment, modification or supplement that may adversely affect the interests of
the Noteholders or the ratings of the Notes will be subject to the satisfaction
of the Rating Agency Condition. Any amendment, modification or supplement shall
be deemed to adversely affect the interests of the Noteholders in any material
respect and the ratings of the Notes unless an authorized officer of the
Administrator shall have delivered to the Collateral Agent a certificate
certifying that any such amendment, modification or supplement will not
adversely affect the interests of the Noteholders or the ratings of the Notes.
Notwithstanding the foregoing, any amendment, modification or supplement that
would extend the due date for, or reduce the amount of any scheduled repayment
or prepayment of principal of or interest on any Note (or reduce the principal
amount of or rate of interest on any Note) requires the consent of each affected
Noteholder. The effectiveness of any amendment, modification or supplement to
any Program Document shall be conditioned upon the delivery of a Tax Opinion to
the Collateral Agent and each Secured Liquidity Note Dealer. The Issuer shall
give each Rating Agency and each Secured Liquidity Note Dealer ten Business Days
prior written notice of any amendment, waiver, supplement or modification to
this Agreement. The cost and expenses associated with

                                       10
<PAGE>

any such amendment, waiver, supplement or modification shall be borne by the
party requesting such amendment, waiver, supplement or modification.

      SECTION 4.2 Governing Law.

      THIS SECURITIES SALE AND CONTRIBUTION AGREEMENT AND THE RIGHTS, DUTIES,
OBLIGATIONS AND RESPONSIBILITIES OF THE PARTIES HERETO SHALL BE GOVERNED IN
ACCORDANCE WITH THE INTERNAL LAWS AND DECISIONS OF THE STATE OF NEW YORK WITHOUT
REGARD TO CONFLICTS OF LAW PRINCIPLES EXCEPT THAT THE PARTIES HERETO INTEND THAT
THE PROVISIONS OF SECTIONS 5-1401 AND 5-1402 OF THE NEW YORK GENERAL OBLIGATIONS
LAW SHALL APPLY TO THIS AGREEMENT.

      SECTION 4.3 Duration of Agreement.

      This Securities Sale and Contribution Agreement shall continue in
existence and effect until the termination of the Depositor's purchase
commitment in accordance with Section 2.4. Notwithstanding the termination of
this Securities Sale and Contribution Agreement, the Seller shall remain liable
to the Depositor, the Issuer and the Collateral Agent pursuant to Article III
with respect to any Securities previously sold by the Seller hereunder.

      SECTION 4.4 Notices.

      All demands, notices and communications hereunder shall be in writing and
shall be deemed to have been duly given if personally delivered at, mailed by
registered mail, postage prepaid, or sent by telecopier, addressed as follows
(or at such other address as shall be specified in a notice furnished
hereunder):

            (i)    if to the Seller:

                   Thornburg Mortgage, Inc.
                   150 Washington Avenue
                   Suite 302
                   Santa Fe, New Mexico 87501
                   Attn: John Clarke
                   Telephone No.: (505) 954-5372
                   Facsimile No.: (505) 954-5300
                   E-mail Address: jclarke@thornburgmortgage.com

                   and

                                       11
<PAGE>

            (ii)   if to the Depositor:

                   Thornburg Mortgage Depositor, L.L.C.
                   c/o Thornburg Mortgage, Inc.
                   150 Washington Avenue
                   Suite 302
                   Santa Fe, New Mexico 87501
                   Attn: John Clarke
                   Telephone No.: (505) 954-5372
                   Facsimile No.: (505) 954-5300
                   E-mail Address: jclarke@thornburgmortgage.com.

      SECTION 4.5 Severability of Provisions.

      If any one or more of the covenants, agreements, provisions or terms of
this Securities Sale and Contribution Agreement shall be held invalid for any
reason whatsoever, then such covenants, agreements, provisions or terms shall be
deemed severable from the remaining covenants, agreements, provisions or terms
of this Securities Sale and Contribution Agreement and shall in no way affect
the validity or enforceability of the other provisions of this Securities Sale
and Contribution Agreement.

      SECTION 4.6 Relationship of Parties.

      Nothing herein contained shall be deemed or construed to create a
partnership or joint venture between the parties hereto.

      SECTION 4.7 Execution in Counterparts.

      This Securities Sale and Contribution Agreement may be executed in one (1)
or more counterparts and by the different parties hereto on separate
counterparts, each of which, when so executed, shall be deemed to be an
original; such counterparts, together, shall constitute one (1) agreement.

      SECTION 4.8 Non-Petition Agreement.

      Notwithstanding any prior termination of this Securities Sale and
Contribution Agreement, the Seller agrees that it shall not, prior to the date
which is one year and one day (or if longer, the applicable preference period
then in effect) after the payment in full of the Notes or any other rated
obligations of the Issuer, acquiesce, petition or otherwise, directly or
indirectly, invoke or cause the Depositor or the Issuer to invoke the process of
any governmental authority for the purpose of commencing or sustaining a case
against the Depositor or the Issuer under any federal or state bankruptcy,
insolvency or similar law or appointing a receiver, liquidator, assignee,
trustee, custodian, sequestrator or other similar official of the Depositor or
the Issuer or any substantial part of the property of the Depositor or the
Issuer, as applicable or ordering the winding up or liquidation of the affairs
of the Depositor or the Issuer.

                                       12
<PAGE>

      SECTION 4.9 No Recourse.

            (a)   As to the Seller. The directors, officers, employees or agents
of the Seller shall not be under any liability to the Depositor, Collateral
Agent, Issuing and Paying Agent or any other Secured Party, it being expressly
understood that all such liability is expressly waived and released as a
condition of, and as consideration for, the execution of this Agreement;
provided, however, that nothing in this Section 4.9 shall relieve any of the
foregoing Persons from any liability which such Person may otherwise have for
his or its gross negligence or willful misconduct. The Seller and any director,
officer, employee or agent of the Seller may rely in good faith on any Program
Document or any other document prima facie properly prepared, executed and/or
delivered in connection therewith by any party to such Program Document.

            (b)   As to the Depositor. The obligations of the Depositor under
this Agreement are solely the obligations of the Depositor. No recourse shall be
had for any obligation or claim arising out of or based upon this Securities
Sale and Contribution Agreement against any member, manager, holder of any
beneficial interest, officer or employee or agent of the Depositor; provided,
however, that nothing in this Section 4.9 shall relieve any of the foregoing
Persons from any liability which such Person may otherwise have for his or its
gross negligence or willful misconduct. Notwithstanding any provisions contained
in this Securities Sale and Contribution Agreement to the contrary, the
Depositor shall not, and shall not be obligated to, pay any amount due hereunder
including, without limitation, any fees, costs or expenses due pursuant to this
Securities Sale and Contribution Agreement unless the Depositor has received
funds which may be used to make such payment. Any amount which the Depositor
does not pay pursuant to the operation of the preceding sentence shall not
constitute a claim (as defined in Section 101 of the Bankruptcy Code) against or
obligation of the Depositor for any such insufficiency unless and until the
Depositor satisfies the provisions of such preceding sentence.

      SECTION 4.10 Survival. The provisions set forth in Article III and
Sections 4.8 and 4.9 shall survive the termination of this Securities Sale and
Contribution Agreement.

                                    ARTICLE V
                                   ASSIGNMENT

      SECTION 5.1 Successors and Assigns; Assignment of Securities Sale and
Contribution Agreement.

      This Securities Sale and Contribution Agreement shall bind and inure to
the benefit of and be enforceable by the Seller, the Depositor and their
respective successors and assigns. The obligations of the Seller under this
Securities Sale and Contribution Agreement cannot be assigned or delegated to a
third party (x) without the consent of the Depositor, which consent shall be at
the Depositor's sole discretion and (y) without satisfaction of the Rating
Agency Condition. The parties hereto acknowledge that the Depositor is acquiring
the Securities for the purpose of selling them to the Issuer who will in turn
pledge the Securities to the Collateral Agent for the benefit of the Secured
Parties. As an inducement to the Depositor to purchase the Securities, the
Seller acknowledges and consents to (i) the assignment by the Depositor to the
Issuer of any or all of the Depositor's rights against the Seller pursuant to
this Securities Sale and

                                       13
<PAGE>

Contribution Agreement and to the enforcement or exercise of any right or remedy
against the Seller pursuant to this Agreement as assigned by the Depositor and
(ii) the assignment by the Issuer to the Collateral Agent of such rights and to
the enforcement or exercise of any right or remedy by the Collateral Agent,
against the Seller pursuant to this Securities Sale and Contribution Agreement
as assigned by the Issuer. Such enforcement of a right or remedy by the Issuer,
the Collateral Agent shall have the same force and effect as if the right or
remedy had been enforced or exercised by the Depositor directly.

                                       14
<PAGE>

        IN WITNESS WHEREOF, the Seller and the Depositor have caused their names
to be signed hereto by their respective officers thereunto duly authorized as of
the day and year first above written.

                                        THORNBURG MORTGAGE, INC.
                                          as Seller

                                        By: /s/ John D. Clarke
                                            ---------------------------
                                        Name:  John D. Clarke
                                        Title: Assistant Vice President

                                        THORNBURG MORTGAGE DEPOSITOR,
                                        LLC,
                                          as Depositor

                                        By: Thornburg Mortgage, Inc., as Manager

                                        By: /s/ John D. Clarke
                                            ---------------------------
                                        Name:  John D. Clarke
                                        Title: Assistant Vice President

                                      Securities Sale and Contribution Agreement

                                       S-1

<PAGE>

                                                                       EXHIBIT A

                           FORM OF TRANSFER SUPPLEMENT

                                                   [Date]

Thornburg Mortgage Depositor, L.L.C.
c/o Thornburg Mortgage, Inc.
150 Washington Avenue
Suite 302
Santa Fe, New Mexico 87501
Attn: John Clarke

                              Purchase Terms Letter

Ladies and Gentlemen:

      Thornburg Mortgage, Inc. (the "Seller") and Thornburg Mortgage Depositor,
L.L.C. (the "Depositor") herewith confirm the terms and provisions of the
Securities Sale and Contribution Agreement (as amended, modified or
supplemented, the "Securities Sale and Contribution Agreement") entered into on
June 30, 2004, pursuant to which the Seller and the Depositor agreed upon the
terms under which the Seller would from time to time sell certain assets to the
Depositor.

      Upon execution of this Transfer Supplement by the Seller and the Depositor
and receipt of the Depositor Purchase Price therefor, the Seller hereby sells,
assigns, transfers, sets over and conveys to the Depositor all right, title and
interest of the Seller in, to and under each Eligible Security identified on the
attached Eligible Security Schedule (collectively, the "Eligible Securities").

            (i)   Closing Date: [______________, _____] The aggregate Depositor
                  Purchase Price for the Eligible Securities shall be paid by
                  the Depositor to the Seller in immediately available funds on
                  such Closing Date.

            (ii)  Depositor Purchase Price: The aggregate Depositor Purchase
                  Price for the Eligible Securities shall be [________].

            (iii) Eligible Security Characteristics: The Eligible Securities
                  have the characteristics set forth on the Eligible Security
                  Schedule, set forth as Exhibit I attached hereto as of the
                  date hereof. The Market Value set forth in Exhibit I has been
                  determined on the date hereof in accordance with Section 3.02
                  of the Administration Agreement.

            (iv)  Representations and Warranties: Each representation and
                  warranty of the Seller set forth in Section 3.1 and Section
                  3.2 of the Securities Sale and

                                      A-1
<PAGE>

                  Contribution Agreement will be true and correct in all
                  material respects on the Closing Date.

            (v)   Terms: All references herein to the Eligible Securities shall
                  be deemed to refer only to the Eligible Securities described
                  in the Eligible Security Schedules attached hereto.

            (vi)  Definitions: Capitalized terms used herein but not otherwise
                  defined herein shall have the meanings ascribed to such terms
                  in the Securities Sale and Contribution Agreement.

                                      A-2
<PAGE>

      Kindly acknowledge your agreement and consent to the terms of this letter
by signing and returning to us the enclosed duplicate copy hereof.

                                           Very truly yours,

                                           THORNBURG MORTGAGE, INC.

                                           By:__________________________________
                                              Name:
                                              Title:

Date:____________________

Consented and Agreed to:

THORNBURG MORTGAGE DEPOSITOR, L.L.C.,
 as Depositor

By: Thornburg Mortgage, Inc., as Manager

By: _________________________________
Name:________________________________
Title:_______________________________

                                      A-3
<PAGE>

                        Exhibit I to Transfer Supplement

                           Eligible Security Schedule

(1) Name of Issuer/Agency;

(2) Group;

(3) Depositor Purchase price;

(4) Market Value;

(5) PAR Value; and

(6) Maturity Date.

                                      A-4