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                                                                     EXHIBIT 1.1

                      ORIGEN RESIDENTIAL SECURITIES, INC..

                           $165,300,000 (Approximate)

                      Origen Manufactured Housing Contract
                           Trust Notes, Series 2005-A

                             UNDERWRITING AGREEMENT

                                                              New York, New York
                                                              May 9, 2005

Citigroup Global Markets Inc.
390 Greenwich Street, 4th Floor
New York, New York 10013

Dear Sir or Madam:

            Origen Manufactured Housing Contract Trust 2005-A (the "Issuer"), a
Delaware statutory trust, proposes to issue Origen Manufactured Housing Contract
Trust Collateralized Notes, Series 2005-A (the "Notes"), under an Indenture (the
"Indenture") dated as of May 1, 2005 between the Issuer and JPMorgan Chase Bank
as indenture trustee (the "Indenture Trustee"). The Issuer was formed pursuant
to a Trust Agreement, dated as of May 1, 2005 (the "Trust Agreement"), among
Wilmington Trust Company, as owner trustee, JPMorgan Chase Bank, as certificate
paying agent and certificate registrar, and Origen Residential Securities, Inc.
(the "Company"), as depositor. The Company hereby proposes to sell the Notes to
you (the "Underwriter"). The Notes are designated as (i) the Class A-1 Notes,
the Class A-2 Notes, the Class A-3 Notes and the Class A-4 Notes (collectively,
the "Class A Notes"), and (ii) the Class M-1 Notes, the Class M-2 Notes and the
Class B Notes (collectively, the "Mezzanine Notes").

            Payments on the Notes will be secured by a trust estate consisting
primarily of a segregated pool (the "Contract Pool") of manufactured housing
installment sales contracts and installment loan agreements (the "Contracts").
Each Contract provides for an original term to maturity of not greater than 30
years. The Contracts will be acquired by the Company from Origen Securitization
Company, LLC (the "Seller") in exchange for immediately available funds
representing the purchase price. The Seller has acquired the Contracts from
Origen Financial L.L.C. (the "Originator" and, together with the Company and the
Seller, the "Origen Companies"; the Origen Companies also referred to herein
individually as an "Origen Company"). The Notes are described more fully in
Schedule I hereto. The Class A Notes and the Mezzanine Notes are more fully
discussed in a registration statement which the Company has furnished to you.
This is to confirm the arrangements with respect to your purchase of the Notes.

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            Capitalized terms used but not defined herein shall have the
meanings assigned thereto in Appendix A to the Indenture.

      1. Representations and Warranties: The Origen Companies represent and
warrant to, and agree with, the Underwriter that:

      (a) The Company has filed with the Securities and Exchange Commission (the
      "Commission") a registration statement on Form S-3 (the file number of
      which is set forth on Schedule A hereto), for the registration of the
      Notes under the Securities Act of 1933, as amended (the "1933 Act"), which
      registration statement has become effective and copies of which have
      heretofore been delivered to you. Such registration statement, as amended
      as of the date hereof, meets the requirements set forth in Rule
      415(a)(1)(vii) under the 1933 Act and complies in all other material
      respects with the 1933 Act and the rules and regulations thereunder. The
      Company proposes to file with the Commission pursuant to Rule 424 under
      the 1933 Act a supplement to the form of prospectus included in such
      registration statement relating to the Notes and the plan of distribution
      thereof, and has previously advised you of all further information
      (financial and other) with respect to the Notes and the Contract Pool to
      be set forth therein. Such registration statement, including the exhibits
      thereto, as amended as of the date hereof, is hereinafter called the
      "Registration Statement"; the prospectus included in the Registration
      Statement after the Registration Statement, as amended, became effective,
      or as subsequently filed with the Commission pursuant to Rule 424 under
      the 1933 Act, is hereinafter called the "Basic Prospectus"; the form of
      prospectus supplemented by the supplement to the form of prospectus
      relating to the Notes, in the form in which it shall be first filed with
      the Commission pursuant to Rule 424 (including the Basic Prospectus as so
      supplemented) is hereinafter called a "Final Prospectus." Any preliminary
      form of any Final Prospectus that has heretofore been filed pursuant to
      Rule 424 or, prior to the effective date of the Registration Statement,
      pursuant to Rule 402(a) or 424(a), is hereinafter called a "Preliminary
      Final Prospectus." Subject to the Underwriter's compliance with its
      obligations pursuant to Section 4(b), the Company shall file any
      Computational Materials and ABS Term Sheets (as each defined herein)
      provided to it by the Underwriter under Section 4(c)(iii), except to the
      extent of any information set forth therein that constitutes Collateral
      Information (as defined below), with the Commission on Form 8-K
      concurrently (to the extent practicable) with the filing of the Prospectus
      Supplement under Rule 424(b) under the 1933 Act on the business day
      immediately following the date that the Final Prospectus is dated (the
      "Final Prospectus Date"). As used herein, "Collateral Information" means
      information with respect to the characteristics of the Contracts and
      administrative and servicing fees, as provided by or on behalf of the
      Depositor to the Underwriter in final form and set forth in the Prospectus
      Supplement. The Company will file with the Commission within fifteen days
      of the issuance of the Notes a report on Form 8-K setting forth specific
      information concerning the Notes and the Contract Pool to the extent that
      such information is not set forth in the Final Prospectus.

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      (b) As of the date hereof, when the Preliminary Final Prospectus is first
      filed pursuant to Rule 424 under the 1933 Act, when the Final Prospectus
      is first filed pursuant to Rule 424 under the 1933 Act, when, prior to the
      Closing Date (as hereinafter defined), any amendment to the Registration
      Statement becomes effective, when any supplement to the Final Prospectus
      is filed with the Commission, and at the Closing Date, (i) the
      Registration Statement, as amended as of any such time, the Preliminary
      Final Prospectus as amended or supplemented as of any such time and the
      Final Prospectus, as amended or supplemented as of any such time, comply
      and will comply in all material respects with the applicable requirements
      of the 1933 Act and the rules and regulations thereunder, (ii) the
      Registration Statement, as amended as of any such time, does not and will
      not contain any untrue statement of material fact and does not and will
      not omit to state any material fact required to be stated therein or
      necessary in order to make the statements therein not misleading, (ii) the
      Preliminary Final Prospectus, as amended or supplemented as of any such
      time, does not and will not contain any untrue statement of a material
      fact and does not and will not omit to state a material fact necessary to
      make the statements therein, in the light of the circumstances under which
      they were made, not misleading; and (iii) the Final Prospectus, as amended
      or supplemented as of any such time, does not and will not contain any
      untrue statement of a material fact and does not and will not omit to
      state a material fact necessary to make the statements therein, in the
      light of the circumstances under which they were made, not misleading;
      provided, however, that the Origen Companies make no representations or
      warranties as to (i) the information contained in or omitted from the
      Registration Statement, the Preliminary Final Prospectus or Final
      Prospectus or any amendment thereof or supplement thereto in reliance upon
      and in conformity with the information furnished in writing to the Company
      by or on behalf of the Underwriter specifically for use in connection with
      the preparation of the Registration Statement and the Final Prospectus as
      set forth on Exhibit A hereto (the "Underwriter's Information") or (ii)
      Derived Information in any Computational Materials or ABS Term Sheets
      required to be provided by the Underwriter to the Company pursuant to
      Section 4(b).

      (c) Each of the Origen Companies has been duly incorporated and is validly
      existing as a corporation or limited liability company in good standing
      under the laws of the State of Delaware with full power and authority
      (corporate and other) to own its properties and conduct its business as
      now conducted by it and to enter into and perform its obligations under
      each of the following agreements to which it is a party: (i) this
      agreement, (ii) the Asset Purchase Agreement, dated as of May 1, 2005 (the
      "Purchase Agreement"), among the Company, the Originator and the Seller
      (iii) the Indenture, (iv) the Servicing Agreement, dated as of May 1, 2005
      (the "Servicing Agreement"), among Origen Financial L.L.C., as servicer (
      the "Servicer"), Origen Servicing, Inc. (the "Subservicer"), the Issuer
      and the Indenture Trustee and (v) the Trust Agreement (this agreement, the
      Purchase Agreement the Servicing Agreement, the Indenture and the Trust
      Agreement individually, an "Agreement" and collectively, the
      "Agreements"); and none of the Origen Companies has received any notice of
      proceedings relating to the revocation or modification of any license,
      certificate, authority or permit applicable to its owning such properties
      or conducting such business which singly or in the aggregate, if the
      subject of

                                                                               3

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      an unfavorable decision, ruling or finding, would materially and adversely
      affect the conduct of the business, operations, financial condition or
      income of such Origen Company.

      (d) As of the date hereof, when the Final Prospectus is first filed
      pursuant to Rule 424 under the 1933 Act, when, prior to the Closing Date
      (as hereinafter defined), any amendment to the Registration Statement
      becomes effective, when any supplement to the Final Prospectus is filed
      with the Commission, and at the Closing Date, there has not and will not
      have been (i) any request by the Commission for any further amendment of
      the Registration Statement or the Final Prospectus or for any additional
      information, (ii) any issuance by the Commission of any stop order
      suspending the effectiveness of the Registration Statement or the
      institution or threatening of any proceeding for that purpose or (iii) any
      notification with respect to the suspension of the qualification of the
      Notes for sale in any jurisdiction or the initiation or threatening of any
      proceeding for such purpose.

      (e) Each of the Agreements when executed and delivered as contemplated
      hereby and thereby will have been, duly authorized, executed and delivered
      by each Origen Company that is a party to such Agreement and each
      constitutes, or will constitute when so executed and delivered, a legal,
      valid and binding agreement of that Origen Company, enforceable against
      such Origen Company in accordance with its terms, except as enforceability
      may be limited by (i) bankruptcy, insolvency, liquidation, receivership,
      moratorium, reorganization or other similar laws affecting the enforcement
      of the rights of creditors, (ii) general principles of equity, whether
      enforcement is sought in a proceeding in equity or at law and (iii) public
      policy considerations underlying the securities laws, to the extent that
      such public policy considerations limit the enforceability of the
      provisions of such Agreement that purport to provide indemnification from
      securities law liabilities.

      (f) The Notes and each of the Agreements will conform in all material
      respects to the description thereof contained in the Preliminary Final
      Prospectus, the Final Prospectus, and the Notes, when duly and validly
      authorized, executed, authenticated and delivered in accordance with the
      Indenture and paid for by the Underwriter as provided herein, will be
      entitled to the benefits of the Indenture. On the Closing Date, the Trust
      Agreement will be effective to establish the Trust as a valid trust under
      the laws of the State of Delaware.

      (g) As of the Closing Date, the Contracts will meet the criteria for
      selection described in the Final Prospectus.

      (h) Neither the issuance and sale of the Notes, nor the execution and
      delivery by any of the Origen Companies of each Agreement to which it is a
      party, nor the consummation by any Origen Company of any of the
      transactions herein or therein contemplated, nor compliance by the Origen
      Companies with the provisions hereof or thereof, will conflict with or
      result in a breach of any term or provision of the certificate of
      incorporation, by-laws or operating agreement of any Origen Company or
      conflict with, result in a breach, violation or acceleration of or
      constitute a default under, the terms of any indenture or

                                                                               4

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      other agreement or instrument to which an Origen Company or any of its
      affiliates is a party or by which it or any of them is bound, or any
      statute, order or regulation applicable to such Origen Company or any of
      its affiliates of any court, regulatory body, administrative agency or
      governmental body having jurisdiction over the Company or any of its
      affiliates. None of the Origen Companies nor any of their affiliates is a
      party to, bound by or in breach or violation of any indenture or other
      agreement or instrument, or subject to or in violation of any statute,
      order or regulation of any court, regulatory body, administrative agency
      or governmental body having jurisdiction over it, which materially and
      adversely affects, or may in the future materially and adversely affect,
      (i) validity or enforceability of, or the ability of the Origen Companies
      to perform their obligations under, this Agreement, the Purchase Agreement
      or the Trust Agreement or (ii) the business, operations, financial
      conditions, properties or assets of the Origen Companies.

      (i) There are no actions or proceedings against, or investigations of, any
      Origen Company pending, or, to the knowledge of an Origen Company,
      threatened, before any court, administrative agency or other tribunal (i)
      asserting the invalidity of any of the Agreements to which it is a party
      or the Notes, (ii) seeking to prevent the issuance of the Notes or the
      consummation of any of the transactions contemplated by any of the
      Agreements to which it is a party, (iii) that might materially and
      adversely affect the performance by an Origen Company of its obligations
      under, or the validity or enforceability of, any Agreement to which it is
      a party or the Notes, or (iv) seeking to affect adversely the federal
      income tax attributes of the Notes as described in the Final Prospectus.

      (j) There has not been any material adverse change in the business,
      operations, financial condition, properties or assets of any of the Origen
      Companies since [January 31, 2005].

      (k) Any taxes, fees and other governmental charges payable by the Origen
      Companies in connection with the execution, delivery and issuance of this
      Agreement, the Purchase Agreement and the Trust Agreement or the
      execution, delivery and sale or transfer of the Notes have been or will be
      paid at or prior to the Closing Date.

      (l) None of the Issuer or the Origen Companies is, and the issuance and
      sale of the Notes in the manner contemplated by the Final Prospectus will
      not cause any of the Issuer or the Origen Companies to be, subject to
      registration or regulation as an investment company or affiliate of an
      investment company under the Investment Company Act of 1940, as amended
      (the "Investment Company Act").

      (m) Any certificate signed by an officer of the Issuer or any of the
      Origen Companies Company and delivered to an Underwriter or counsel for
      the Underwriters in connection with an offering of the Notes shall be
      deemed, and shall state that it is, a representation and warranty as to
      the matters covered thereby to each person to whom the representations and
      warranties in this Section 1 are made.

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      (n) Since the date as of which information is given in the Final
      Prospectus, there has not been any material adverse change in the general
      affairs, management, financial condition, or results of operations of the
      Origen Companies, otherwise than as set forth or contemplated in the Final
      Prospectus, as supplemented or amended as of the Closing Date.

      (o) The Preliminary Final Prospectus was, and the Final Prospectus
      delivered to the Underwriter for use in connection with this offering will
      be, identical to the versions of the Preliminary Final Prospectus and
      Final Prospectus created to be transmitted to the Commission for filing
      via the Electronic Data Gathering Analysis and Retrieval System ("EDGAR"),
      except to the extent permitted by Regulation S-T.

      (p) No Origen Company has taken, and will not take, directly or
      indirectly, any action which is designed to or which has constituted or
      which might reasonably be expected to cause or result in stabilization or
      manipulation of the price of any security of an Origen Company to
      facilitate the sale or resale of the Notes.

      (q) Neither an Origen Company nor any of its affiliates (i) is required to
      register as a "broker" or "dealer" in accordance with the provisions of
      the Exchange Act, or the rules and regulations thereunder (the "Exchange
      Act Regulations"), or (ii) directly, or indirectly through one or more
      intermediaries, controls or has any other association with (within the
      meaning of Article I of the Bylaws of the NASD) any member firm of the
      NASD.

      (r) No Origen Company has relied upon the Underwriter for any legal, tax
      or accounting advice in connection with the offering and sale of the
      Notes.

      (s) The Pool Information is accurate, true and correct.

      2. Purchase and Sale. Subject to the terms and conditions and in reliance
upon the representations and warranties set forth herein, the Company agrees to
sell to the Underwriter, and the Underwriter agrees to purchase from the Company
on the Closing Date, at the purchase price to public less the underwriting
discounts and commission for each class set forth in Schedule II hereto, the
Notes set forth in Schedule II hereto.

      3. Delivery and Payment. Delivery of and payment for the Notes shall be
made in the manner, on the date and at the time specified in Schedule I hereto
(or such later date not later than seven business days after such specified date
as the Underwriter shall designate), which date and time may be postponed by
agreement between the Underwriter and the Company or as provided in Section 9
hereof (such date and time of delivery and payment for the Notes being herein
called the "Closing Date"). Delivery of the Notes, as set forth on Schedule I
hereto, shall be made to the Underwriter against payment in same day Federal
funds by the Underwriter of the purchase price. The Notes shall be registered in
such names and in such authorized denominations as the Underwriter may request
not less than three full business days in advance of the Closing Date.

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            The Company agrees to have the Notes available for inspection,
checking and packaging by the Underwriter in New York, New York, not later than
1:00 p.m. New York time on the business day prior to the Closing Date.

      4. Offering by Underwriter.

      (a) It is understood that the Underwriter proposes to offer the Notes for
      sale to the public as set forth in the Final Prospectus.

      (b) [Reserved].

      (c) It is understood that the Underwriter may prepare and provide to
      prospective investors certain Computational Materials and ABS Term Sheets
      in connection with their offering of the Notes, subject to the following
      conditions:

      (i) The Underwriter shall comply with all applicable laws and regulations
      in connection with the use of Computational Materials, including the
      No-Action Letter of May 20, 1994 issued by the Commission to Kidder,
      Peabody Acceptance Corporation I, Kidder, Peabody & Co. Incorporated and
      Kidder Structured Asset Corporation, as made applicable to other issuers
      and underwriters by the Commission in response to the request of the
      Public Securities Association dated May 24, 1994 (together, the
      "Kidder/PSA Letter"), and including the PSA Letter referred to below. The
      Underwriter shall comply with all applicable laws and regulations in
      connection with the use of ABS Term Sheets, including the No-Action Letter
      of February 17, 1995 issued by the Commission to the Public Securities
      Association (the "PSA Letter" and, together with the Kidder/PSA Letter,
      the "No-Action Letters"). For purposes hereof, the term "Computational
      Materials" shall have the meaning set forth in the No-Action Letters and
      the terms "ABS Term Sheets" and "Collateral Term Sheets" as used herein
      shall have the meaning set forth in the PSA Letter.

      (ii) All Computational Materials and ABS Term Sheets provided to
      prospective investors shall be in a form approved by the Company, it being
      understood that the Company shall have the right to require specific
      legends or notations to appear on any Computational Materials and ABS Term
      Sheets, the right to require changes regarding the use of terminology and
      the right to determine the types of information appearing therein. The
      Underwriter shall provide the Company with representative forms of all
      Computational Materials and ABS Term Sheets not less than five business
      days prior to their first use, to the extent such forms have not
      previously been approved (or differ from forms previously approved) by the
      Company for use by the Underwriter in this offering.

      (iii) The Underwriter shall provide to the Company for filing on Form 8-K
      as provided in Section 1(a) copies (in such written or electronic format
      as required by the Company) of:

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            (A) all Computational Materials and ABS Term Sheets that are
            required to be filed with the Commission pursuant to the terms of
            the No-Action Letters (including successive versions) relating to
            any class of Notes that were sent to any prospective investor,
            regardless of whether such Computational Materials and ABS Term
            Sheets reflect the final structure of the Notes, if such prospective
            investor indicated an interest in purchasing any portion of such
            class, and

            (B) all Computational Materials and ABS Term Sheets (including
            successive versions) relating to any class of Notes that were sent
            to any prospective investor, if such Computational Materials and ABS
            Term Sheets are consistent with the final structure of the Notes as
            it relates to such class;

      provided, that such Computational Materials and ABS Term Sheets were
      generated based on assumptions regarding the terms of any class of the
      Notes purchased by the Underwriter and were provided to prospective
      investors either prior to the time of filing of each respective Final
      Prospectus under Rule 424(b) under the 1933 Act or without being
      accompanied or preceded by a copy of each respective Final Prospectus. The
      Underwriter may, or if requested by the Company shall, provide copies of
      the foregoing in a consolidated or aggregated form including all
      information described above. All Computational Materials and ABS Term
      Sheets described in this subsection (iii) must be provided to the Company
      not later than 3:00 p.m. Eastern Standard Time on the Final Prospectus
      Date, in such form as may be required by the Company so as to permit the
      filing thereof by the Company with the Commission on Form 8-K concurrently
      with the filing of each respective Final Prospectus under Rule 424(b)
      under the 1933 Act on the business day immediately following each
      respective Final Prospectus Date.

      (iv) The Underwriter shall not provide any Computational Materials or ABS
      Term Sheets to any prospective investor after the Computational Materials
      or ABS Term Sheets are provided to the Company in accordance with
      subsection (iii) above, unless and until (a) the Final Prospectus has been
      filed with the Commission and (b) such Computational Materials or ABS Term
      Sheets are accompanied or preceded by a copy of the Final Prospectus. The
      Underwriter shall not send any confirmation to any prospective investor in
      the Notes until all Computational Materials and ABS Term Sheets referred
      to in subsection (iii) above have been filed with the Commission.

      (v) The Underwriter either (A) has not provided any potential investor
      with a Collateral Term Sheet (that is required to be filed with the
      Commission within two Business Days of first use under the terms of the
      PSA Letter as described above) or (B) has, prior to or substantially
      contemporaneously with, but in no event later than one (1) Business Day
      following, its first delivery of such Collateral Term Sheet to a potential
      investor, delivered such Collateral Term Sheet to the Company or its
      counsel.


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 5. Agreements. The Origen Companies agree with the Underwriter that:

      (a) The Company will not file any amendment or supplement to the
      Registration Statement, the Preliminary Final Prospectus Supplement or the
      Final Prospectus, unless the Company has furnished to you a copy for your
      review prior to filing, and will not file or distribute any such proposed
      amendment or supplement to which you reasonably object. Subject to the
      foregoing sentence, the Company will cause the Final Prospectus to be
      transmitted to the Commission for filing pursuant to Rule 424 under the
      1933 Act. The Company will promptly advise the Underwriter (i) when the
      Final Prospectus shall have been filed or transmitted to the Commission
      for filing pursuant to Rule 424, (ii) when any amendment to the
      Registration Statement shall have become effective, (iii) of any request
      by the Commission for any amendment of the Registration Statement or the
      Final Prospectus or for any additional information, (iv) of the issuance
      by the Commission of any stop order suspending the effectiveness of the
      Registration Statement or the institution or threatening of any proceeding
      for that purpose and (v) of the receipt by the Company of any notification
      with respect to the suspension of the qualification of the Notes for sale
      in any jurisdiction or the initiation or threatening of any proceeding for
      such purpose. The Company will use its best efforts to prevent the
      issuance of any such stop order or suspension and, if issued, to obtain as
      soon as possible the withdrawal thereof.

      (b) If, at any time when a prospectus relating to the Notes is required to
      be delivered under the 1933 Act, any event occurs as a result of which any
      Final Prospectus as then amended or supplemented would include any untrue
      statement of a material fact or omit to state any material fact necessary
      to make the statements therein in the light of the circumstances under
      which they were made not misleading, or if it shall be necessary to amend
      or supplement the Final Prospectus to comply with the 1933 Act or the
      rules and regulations thereunder, the Company will promptly prepare and
      file with the Commission, subject to paragraph (a) of this Section 5, an
      amendment or supplement that will correct such statement or omission or an
      amendment that will effect such compliance and, if such amendment or
      supplement is required to be contained in a post-effective amendment of
      the Registration Statement, will use its best efforts to cause such
      amendment of the Registration Statement to be made effective as soon as
      possible.

      (c) The Company will (i) furnish to the Underwriter and counsel for the
      Underwriter, without charge, upon reasonable request, signed copies of the
      Registration Statement (including exhibits thereto) and each amendment
      thereto that shall become effective on or prior to the Closing Date and,
      so long as delivery of a prospectus by an Underwriter or dealer in
      connection with the Notes may be required by the 1933 Act, as many copies
      of each Preliminary Final Prospectus, the Final Prospectus and any
      amendments thereof and supplements thereto as the Underwriter may
      reasonably request, and (ii) file promptly all reports and any definitive
      proxy or information statements required to be filed by the Company with
      the Commission pursuant to Section 13(a), 13(c), 14 or 15(d) of the
      Securities Exchange Act of 1934, as amended (the "1934 Act"), subsequent
      to the date of the Final Prospectus and for so long as the delivery of a
      prospectus by an Underwriter or dealer in connection with the Notes may be
      required under the 1933 Act.

                                                                               9

<PAGE>

      (d) The Company agrees that, so long as the Notes shall be outstanding, it
      will deliver to the Underwriter the annual statement as to compliance
      delivered to the Indenture Trustee pursuant to Section 3.15 of the
      Servicing Agreement and the annual statement of a firm of independent
      public accountants furnished to the Indenture Trustee pursuant to Section
      3.16 of the Servicing Agreement, as soon as such statements are furnished
      to the Company. The Company will request that the Servicer and the
      Indenture Trustee furnish to the Underwriter any monthly reports furnished
      to Noteholders pursuant to the Servicing Agreement and the Indenture.

      (e) The Company will furnish such information, execute such instruments
      and take such action, if any, as may be required to qualify the Notes for
      sale under the laws of such jurisdictions as the Underwriter may designate
      and will maintain such qualifications in effect so long as required for
      the distribution of the Notes; provided, however, that the Company shall
      not be required to qualify to do business in any jurisdiction where it is
      not now so qualified.

      (f) The Origen Companies will pay all costs and expenses in connection
      with the transactions herein contemplated, including, but not limited to:
      the fees and disbursements of its counsel; the costs and expenses of
      printing (or otherwise reproducing) and delivering the Indenture, the
      Trust Agreement, the Servicing Agreement and the Notes; accounting fees
      and disbursements; the costs and expenses in connection with the
      qualification or exemption of the Notes under state securities or blue sky
      laws, including filing fees and reasonable fees and disbursements of
      counsel in connection with the preparation of any blue sky survey and in
      connection with any determination of the eligibility of the Notes for
      investment by institutional investors and the preparation of any legal
      investment survey; the expenses of printing any such blue sky survey and
      legal investment survey; the costs and expenses in connection with the
      preparation, printing and filing of the Registration Statement (including
      exhibits thereto), the Basic Prospectus, the Preliminary Final Prospectus
      and the Final Prospectus, the preparation and printing of this Agreement
      and the furnishing to the Underwriter of such copies of each Preliminary
      Final Prospectus and the Final Prospectus as the Underwriter may
      reasonably request, the fees of each nationally recognized statistical
      rating organization identified in the Final Prospectus (individually and
      collectively, the "Rating Agency") as having rated the Notes and the fees
      of counsel to the Underwriter. Except as provided in Section 7 hereof, the
      Underwriter shall be responsible for paying all costs and expenses
      incurred by them in connection with the offering of the Notes.

      6. Conditions to the Obligations of the Underwriter. The obligations of
the Underwriter to purchase the Notes shall be subject to the accuracy of the
representations and warranties on the part of the Origen Companies contained
herein as of the date hereof, as of the date of the effectiveness of any
amendment to the Registration Statement filed prior to the Closing Date and as
of the Closing Date, to the accuracy of the statements of the Origen Companies
made in any certificates pursuant to the provisions hereof, to the performance
by the Origen Companies of their obligations hereunder and to the following
additional conditions:

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      (a) No stop order suspending the effectiveness of the Registration
      Statement, as amended from time to time, shall have been issued and not
      withdrawn and no proceedings for that purpose shall have been instituted
      or threatened; and the Final Prospectus shall have been filed or
      transmitted for filing with the Commission in accordance with Rule 424
      under the 1933 Act.

      (b) The Company shall have delivered to you a certificate of the Company,
      signed by the President or a vice president or an assistant vice president
      of the Company and dated the Closing Date, to the effect that the signer
      of such certificate has carefully examined the Registration Statement,
      Final Prospectus and this Agreement and that (i) the representations and
      warranties of the Company in this Agreement are true and correct in all
      material respects at and as of the Closing Date with the same effect as if
      made on the Closing Date, (ii) the Company has, in all material respects,
      complied with all the agreements and satisfied all the conditions on its
      part that are required by this Agreement to be performed or satisfied at
      or prior to the Closing Date, (iii) no stop order suspending the
      effectiveness of the Registration Statement has been issued and no
      proceedings for that purpose have been instituted or, to the Company's
      knowledge, threatened, (iv) nothing has come to the attention of such
      officer that would lead such officer to believe that the Final Prospectus
      contains any untrue statement of a material fact or omits to state any
      material fact necessary in order to make the statements therein, in the
      light of the circumstances under which they were made, not misleading and
      (v) subsequent to the respective dates as of which information is given in
      the Final Prospectus, there has not been any material adverse change in
      the general affairs, capitalization, financial condition or results of
      operations of the Company.

      (c) The Underwriter shall have received from Hunton & Williams LLP,
      counsel for the Origen Companies, a favorable opinion or opinions, dated
      the Closing Date and satisfactory in form and substance to the
      Underwriter.

      (d) The Underwriter shall have received from Deloitte & Touche, certified
      public accountants, a letter, dated the date hereof and satisfactory in
      form and substance to the Underwriter and counsel for the Underwriter, to
      the effect that they have performed certain specified procedures as a
      result of which they determined that certain information of an accounting,
      financial or statistical nature set forth in each respective Final
      Prospectus under the captions "Summary of Prospectus Supplement -- The
      Contracts," "Risk Factors" (to the extent of information regarding the
      Contracts therein) "The Contract Pool" "Yield on the Notes" and
      "Description of the Notes" agrees with the records of the Seller.

      (e) The Notes shall have been given the ratings set forth in Schedule I
      hereto by each Rating Agency.

      (f) The Underwriter shall have received, from counsel for the Indenture
      Trustee, a favorable opinion, dated the Closing Date, and in form and
      substance satisfactory to the Underwriter and its counsel, to the effect
      that the Indenture has been duly authorized,

                                                                              11

<PAGE>

      executed and delivered by the Indenture Trustee and constitutes the legal,
      valid and binding agreement of the Indenture Trustee, enforceable in
      accordance with its terms, except as enforceability may be limited by
      bankruptcy, insolvency, reorganization or other similar laws affecting the
      enforcement of creditors rights in general and by general principles of
      equity, regardless of whether such enforcement is considered in a
      proceeding in equity or at law, and as to such other matters as may be
      agreed upon by the Indenture Trustee and the Underwriter.

      (g) The Underwriter shall have received from the Seller, in form and
      substance satisfactory to counsel for the Underwriter:

            (i) An officer's certificate stating that on the Closing Date the
            representations and warranties of the Seller under the Purchase
            Agreement will be true and correct and no event has occurred that
            would constitute a default thereunder; and

            (ii) An officer's certificate relating to the Purchase Agreement and
            the obligations of the Seller thereunder, as Seller or otherwise,
            together with copies of the certificate of incorporation and by-laws
            of the Seller and a certificate of good standing of the Seller under
            the laws of the State of New York;

      (h) The Underwriter shall have received from the Originator in form and
      substance satisfactory to counsel for the Underwriter:

            (i) An officer's certificate stating that on the date each Contract
            is sold to the Seller (i) the representations and warranties of the
            Originator under the Purchase Agreement will be true and correct and
            no event has occurred that would constitute a default thereunder,
            (ii) nothing has come to the attention of such officer that would
            lead such officer to believe that the information set forth with
            respect to the Originator in the Prospectus Supplement and with
            respect to any private placement memorandum, any information of a
            comparable nature, contains any untrue statement of a material fact
            or omits to state any material fact necessary in order to make the
            statements therein, in the light of the circumstances under which
            they were made, not misleading and (iii) subsequent to the
            respective dates as of which information is given in the Prospectus
            Supplement and any private placement memorandum, there has not been
            any material adverse change in the general affairs, capitalization,
            financial condition or results of operations of the Originator; and

            (ii) An officer's certificate relating to the Purchase Agreement and
            the obligations of the Originator thereunder, as Originator or
            otherwise, together with copies of the operating agreement of the
            Originator and a certificate of good standing of the Originator
            under the laws of the State of Delaware.

      (i) The Underwriter shall have received from the Servicer, in form and
      substance satisfactory to counsel for the Underwriter.

                                                                              12

<PAGE>

            (i) An officer's certificate stating that on the Closing Date the
            representations and warranties of the Servicer contained in the
            Servicing Agreement will be true and correct and no event has
            occurred with respect to the Servicer that would constitute an Event
            of Default thereunder;

            (ii) An officer's certificate relating to the Servicing Agreement
            and the obligations of the Servicer thereunder, as Servicer or
            otherwise, and attached thereto the applicable resolutions of the
            board of directors of the Servicer, together with copies of the
            certificate of limited partnership and by-laws of the Servicer and a
            certificate of good standing of the Servicer issued by the State of
            Delaware; and

            (iii) The Underwriter shall have received from counsel to the
            Originator and the Servicer, a favorable opinion, dated the Closing
            Date and satisfactory in form and substance to counsel for the
            Underwriter.

            (j) The Underwriter shall have received copies of any opinions of
counsel to the Company, the Seller, the Originator and the Servicer supplied to
the Rating Agency or the Indenture Trustee relating to certain matters with
respect to the Notes. Any such opinions shall be dated the Closing Date and
addressed to the Underwriter or accompanied by the reliance letters to the
Underwriter or shall state that the Underwriter may rely upon them.

            (k) All proceedings in connection with the transactions contemplated
by this Agreement and all documents incident hereto shall be satisfactory in
form and substance to the Underwriter and counsel for the Underwriter, and the
Underwriter and counsel for the Underwriter shall have received such other
information, certificates and documents as they may reasonably request.

            (l) All documents required under the Purchase Agreement have been
provided to the appropriate parties.

            If any of the conditions specified in this Section 6 shall not have
been fulfilled in all material respects when and as provided in this Agreement,
if the Company is in breach of any covenants or agreements contained herein or
if any of the opinions and certificates mentioned above or elsewhere in this
Agreement shall not be in all material respects reasonably satisfactory in form
and substance to the Underwriter and counsel for the Underwriter, this Agreement
and all obligations of the Underwriter hereunder may be cancelled at, or at any
time prior to, the Closing Date by the Underwriter. Notice of such cancellation
shall be given to the Company in writing, or by telephone or telegraph confirmed
in writing.

      7. Reimbursement of Underwriter's Expenses. If the sale to the Underwriter
of the Notes as provided for herein is not consummated because any condition to
the obligations of the Underwriter set forth in Section 6 hereof is not
satisfied or because of any refusal, inability or failure on the part of the
Origen Companies to perform any agreement herein or comply with any provisions
hereof, other than by reason of default by the Underwriter, the Origen Companies
will

                                                                              13

<PAGE>

reimburse the Underwriter upon demand for all out-of-pocket expenses, including
reasonable fees and disbursements of counsel, that shall have been incurred by
the Underwriter in connection with the proposed purchase and sale of the Notes.

      8. Indemnification and Contribution. The Company agrees with the
Underwriter that:

      (a) The Origen Companies will, jointly and severally, indemnify and hold
      harmless the Underwriter, the directors, officers, employees and agents of
      the Underwriter, and each person who controls the Underwriter within the
      meaning of either the 1933 Act or the 1934 Act against any and all losses,
      claims, damages or liabilities, joint or several, to which they or any of
      them may become subject under the 1933 Act, the 1934 Act or other federal
      or state statutory law or regulation, at common law or otherwise, insofar
      as such losses, claims, damages or liabilities (or actions in respect
      thereof) arise out of or are based upon any untrue statement or alleged
      untrue statement of a material fact contained in the Registration
      Statement, or in the Basic Prospectus, any Preliminary Final Prospectus or
      Final Prospectus, or in any amendment thereof or supplement thereto, 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 not misleading, and agrees to reimburse each such
      indemnified party, as incurred, for any legal or other expenses reasonably
      incurred by them in connection with investigating or defending any such
      loss, claim, damage, liability or action; provided, however, that the
      Origen Companies will not be liable in any such case to the extent that
      any such loss, claim, damage or liability arises out of or is based upon
      any such untrue statement or alleged untrue statement or omission or
      alleged omission made (i) therein in reliance upon and in conformity with
      any Underwriter's Information or (ii) in any Derived Information in any
      Computational Materials or ABS Term Sheets required to be provided by the
      Underwriter to the Company pursuant to Section 4(b). This indemnity
      agreement will be in addition to any liability which the Company may
      otherwise have.

      (b) The Underwriter will indemnify and hold harmless the Company, its
      directors, each of the Company's officers who signs the Registration
      Statement, and each person, if any, who controls the Company within the
      meaning of either the 1933 Act or the 1934 Act, to the same extent as the
      foregoing indemnity from the Origen Companies to the Underwriter, but only
      with reference to (i) Derived Information or (ii) the Underwriter's
      Information. This indemnity agreement will be in addition to any liability
      that the Underwriter may otherwise have.

      (c) Promptly after receipt by an indemnified party under this Section 8 of
      notice of the commencement of any action, such indemnified party will, if
      a claim in respect thereof is to be made against the indemnifying party
      under this Section 8, notify the indemnifying party in writing of the
      commencement thereof; but the failure to so notify the indemnifying party
      (i) will not relieve it from liability under paragraph 8(a) or 8(b) above
      unless such failure results in the forfeiture by the indemnifying party of
      substantial rights and defenses and (ii) will not, in any event, relieve
      the indemnifying party from any obligations to any indemnified party other
      than the indemnification obligation provided in

                                                                              14

<PAGE>

      paragraph 8(a) or 8(b) above. The indemnifying party shall be entitled to
      appoint counsel of the indemnifying party's choice at the indemnifying
      party's expense to represent the indemnified party in any action for which
      indemnification is sought (in which case the indemnifying party shall not
      thereafter be responsible for the fees and expenses of any separate
      counsel retained by the indemnified party or parties except as set forth
      below); provided, however, that such counsel shall be satisfactory to the
      indemnified party. Notwithstanding the indemnifying party's election to
      appoint counsel to represent the indemnified party in an action, the
      indemnified party shall have the right to employ separate counsel
      (including local counsel), and the indemnifying party shall bear the
      reasonable fees, costs and expenses of such separate counsel if (i) the
      use of counsel chosen by the indemnifying party to represent the
      indemnified party would present such counsel with a conflict of interest,
      (ii) the actual or potential defendants in, or targets of, any such action
      include both the indemnified party and the indemnifying party and the
      indemnified party shall have reasonably concluded that there may be legal
      defenses available to it and/or other indemnified parties that are
      different from or additional to those available to the indemnifying party,
      (iii) the indemnifying party shall not have employed counsel satisfactory
      to the indemnified party to represent the indemnified party within a
      reasonable time after notice of the institution of such action or (iv) the
      indemnifying party shall authorize the indemnified party to employ
      separate counsel at the expense of the indemnifying party. An indemnifying
      party will not, without the prior written consent of the indemnified
      parties, settle or compromise or consent to the entry of any judgment with
      respect to any pending or threatened claim, action, suit or proceeding in
      respect of which indemnification or contribution may be sought hereunder
      (whether or not the indemnified parties are actual or potential parties to
      such claim or action) unless such settlement, compromise or consent (i)
      does not include a statement as to or admission of, fault, culpability or
      a failure to act by or on behalf of any such indemnified party, and
      (ii)includes an unconditional release of each indemnified party from all
      liability arising out of such claim, action, suit or proceeding.

      (d) In order to provide for just and equitable contribution in
      circumstances in which the indemnification provided for in paragraph (a)
      of this Section 8 is due in accordance with its terms but is for any
      reason held by a court to be unavailable from the Origen Companies on
      grounds of policy or otherwise, the Origen Companies and the Underwriter
      shall contribute to the aggregate losses, claims, damages and liabilities
      (including legal and other expenses reasonably incurred in connection with
      investigating or defending same) (collectively, "Losses") to which the
      Origen Companies and the Underwriter may be subject in such proportion as
      is appropriate to reflect the relative benefits received by the Origen
      Companies and the Underwriter from the offering of the Notes. If the
      allocation provided by the immediately preceding sentence is unavailable
      for any reason, the Origen Companies and the Underwriter shall contribute
      in such proportion as is appropriate to reflect not only such relative
      benefits but also the relative fault of the Origen Companies and the
      Underwriter in connection with the statements or omissions that resulted
      in such Losses as well as any other relevant equitable consideration.
      Benefits received by the Origen Companies shall be deemed to be equal to
      the total net proceeds from the offering (before deducting expenses) and
      benefits received by an Underwriter

                                                                              15

<PAGE>

      shall be deemed to total discounts and commissions received by the
      Underwriter. Relative fault shall be determined by reference to whether
      any alleged untrue statement or omission relates to the information
      provided by the Origen Companies or the Underwriter. The Origen Companies
      and the Underwriter agree that it would not be just and equitable if
      contribution were determined by pro rata allocation or any other method of
      allocation that does not take account of the equitable considerations
      referred to above. Notwithstanding the foregoing, in no event shall the
      Underwriter be required to contribute any amount in excess of the total
      discounts or commissions received by the Underwriter. Notwithstanding the
      provisions of this paragraph 8(d), no person guilty of fraudulent
      misrepresentation (within the meaning of Section 11(f) of the 1933 Act)
      shall be entitled to contribution from any person who was not guilty of
      such fraudulent misrepresentation. For purposes of this Section 8, each
      person, if any, who controls the Underwriter within the meaning of the
      1933 Act or the 1934 Act and each director, officer, employee and agent of
      the Underwriter shall have the same rights to contribution as the
      Underwriter, and each person, if any, who controls the Origen Companies
      within the meaning of either the 1933 Act or the 1934 Act, each officer of
      an Origen Company who shall have signed the Registration Statement and
      each director of such Origen Company shall have the same rights to
      contribution as such Origen Company, subject in each case to the
      applicable terms and conditions of this paragraph 8(d).

                                                                              16

<PAGE>

            (e) For purposes hereof, as to the Underwriter, the term "Derived
      Information" means such information, if any, in the Computational
      Materials or ABS Term Sheets that is not contained in either (i) the
      Registration Statement, the Basic Prospectus, any Preliminary Final
      Prospectus or Final Prospectus or amendments or supplements thereto,
      taking into account information incorporated therein by reference (other
      than information incorporated by reference from the Computational
      Materials or ABS Term Sheets) or (ii) any Pool Information. "Derived
      Information" also excludes any omission or alleged omission or
      misstatement or alleged misstatement resulting from an error in the Pool
      Information. "Pool Information" means the information furnished to the
      Underwriter with respect to the characteristics of the Contracts.

      9. [Reserved].

      10. Termination. This Agreement shall be subject to termination in the
absolute discretion of the Underwriter, by notice given to the Origen Companies
prior to delivery of and payment for all Notes if prior to such time (i) trading
in securities generally on the New York Stock Exchange shall have been suspended
or limited, or minimum prices shall have been established in such Exchange, (ii)
a banking moratorium shall have been declared by either federal or New York
State authorities or (iii) there shall have occurred any outbreak or material
escalation of hostilities, declaration by the United States of a national
emergency or war or other calamity or crisis, or there shall have occurred such
a material adverse change in general economic, political or financial conditions
(or the effect of international conditions on the financial markets of the
United States shall be such) which is material and adverse, and in the case of
any of the events specified in this clause (iii) such event makes it in the
judgment of the Underwriter, impractical or inadvisable to proceed with the
public offering or the delivery of the Notes on the terms and in the manner
contemplated in the Prospectus Supplement.

      11. Representations and Indemnities to Survive. The respective agreements,
representations, warranties, indemnities and other statements of the Company or
its officers and the Underwriter set forth in or made pursuant to this Agreement
will remain in full force and effect, regardless of any investigation made by or
on behalf of the Underwriter or the Company or any of the officers, directors or
controlling persons referred to in Section 8 hereof, and will survive delivery
of and payment for the Notes. The provisions of Sections 7 and 8 hereof shall
survive the termination or cancellation of this Agreement.

                                                                              17

<PAGE>

      12. Notices. All communications hereunder will be in writing and effective
only on receipt, and, if sent to the Underwriter, will be mailed, delivered or
telegraphed and confirmed to it at 390 Greenwich Street, 4th Floor, New York,
New York 10013, Attention: Managing Director, the Financial Institutions
Department; or, if sent to the Origen Companies, will be mailed, delivered or
telegraphed and confirmed to it at Origen Residential Securities, Inc. 27777
South Franklin Road Suite 1700, Southfield, Michigan 48034 Attention: Ron Klein,
Mark Landschulz and Andy Geater.

      13. Successors. This Agreement will inure to the benefit of and be binding
upon the parties hereto and their respective successors and the officers and
directors and controlling persons referred to in Section 8 hereof, and their
successors and assigns, and no other person will have any right or obligation
hereunder.

      14. Applicable Law. This Agreement will be governed by and construed in
accordance with the laws of the State of New York. This Agreement may be
executed in any number of counterparts, each of which shall for all purposes be
deemed to be an original and all of which shall together constitute but one and
the same instrument.

                                                                              18

<PAGE>

            If the foregoing is in accordance with your understanding of our
agreement, please sign and return to us a counterpart hereof, whereupon this
letter and your acceptance shall represent a binding agreement among the Company
and the Underwriter.

                                                  Very truly yours,

                                                  ORIGEN RESIDENTIAL SECURITIES,
                                                  INC.

                                                  By: /s/ Ronald Klein
                                                      --------------------------
                                                  Name: Ronald Klein
                                                  Title: CEO

                                                  ORIGEN SECURITIZATION COMPANY,
                                                  LLC

                                                  By: /s/ Ronald Klein
                                                      --------------------------
                                                  Name: Ronald Klein
                                                  Title: CEO

                                                  ORIGEN FINANCIAL L.L.C.

                                                  By: /s/ Ronald Klein
                                                      --------------------------
                                                  Name: Ronald Klein
                                                  Title: CEO

The foregoing Agreement is hereby confirmed
and accepted as of the date first above written.

CITIGROUP GLOBAL MARKETS INC.

By: /s/ Jeff Cady
    -------------------------
Name: Jeff Cady
Title: Director

                                                                              19

<PAGE>

                                   SCHEDULE I

Underwriting Agreement, dated May 9, 2005

As used in this Agreement, the term "Registration Statement" refers to
registration statement No. 333-117573 filed by the Company on Form S-3 and
declared effective on August 16, 2004, as amended to date. The term "Basic
Prospectus" refers to the form of Prospectus filed with the Commission pursuant
to Rule 424 under the 1933 Act after the Registration Statement became
effective.

Title and Description of Notes: Origen Manufactured Housing Contract Trust
Collateralized Notes, Series 2005-A.

Initial aggregate principal balance of the Notes: $165,300,000 (Approximate)

<TABLE>
<CAPTION>
Class Designation   Initial Note Principal Balance (1)   Note Rate   S&P   Moody's
-----------------   ----------------------------------   ---------   ---   -------
<S>                 <C>                                  <C>         <C>   <C>
Class A-1                        $44,500,000             4.06%       AAA     Aaa

Class A-2                        $43,000,000             4.49%       AAA     Aaa

Class A-3                        $14,300,000             4.97%       AAA     Aaa

Class A-4                        $21,225,000             5.41% (2)   AAA     Aaa

Class M-1                        $17,575,000             5.46% (2)   AA      Aa2

Class M-2                        $13,300,000             5.86% (2)    A       A2

Class B                          $11,400,000             6.55% (2)   BBB     Baa1
</TABLE>

(1)   Approximate.

(2)   Subject to a rate cap as described in the Indenture.

Closing Time, Date and Location: 10:00 AM. on May 12, 2005 at the offices of
Hunton & Williams LLP, Riverfront Plaza- East Tower, 951 East Byrd Street,
Richmond, Virginia, 23219-4074 and denominations as the Underwriter may direct
in accordance with the Underwriting Agreement.

                                                                              20

<PAGE>

                                   SCHEDULE II

<TABLE>
<CAPTION>
                                                     Underwriting Discount   Proceeds to
  Class     Principal Amount (1)   Price to Public      and Commission        Depositor
---------   --------------------   ---------------   ---------------------   -----------
<S>         <C>                    <C>               <C>                     <C>
Class A-1      $  44,500,000          99.991163%             0.375%          99.616163%

Class A-2      $  43,000,000          99.988043%             0.375%          99.613043%

Class A-3      $  14,300,000          99.997948%             0.375%          99.622948%

Class A-4      $  21,225,000          99.975744%             0.375%          99.600744%

Class M-1      $  17,575,000          99.944330%             0.375%          99.569330%

Class M-2      $  13,300,000          99.987287%             0.375%          99.612287%

 Class B       $  11,400,000          99.999894%             0.375%          99.624894%
</TABLE>

(1)   Approximate.

                                                                              21