<PAGE>

                        Mortgage Loan Purchase Agreement

                  Mortgage Loan Purchase Agreement (the "Agreement"), dated as
of April 27, 2001 between Washington Mutual Mortgage Securities Corp. (the
"Seller") and ABN AMRO Mortgage Corporation (the "Purchaser").

                  Subject to the terms and conditions of this Agreement, the
Seller agrees to sell and the Purchaser agrees to purchase certain mortgage
loans (the "Mortgage Loans") as described herein and as identified on the
Mortgage Loan Schedule defined in Section 2 hereof. The Mortgage Loans will be
purchased on a servicing released basis.

                  Now, therefore, in consideration of the premises and the
mutual agreements set forth herein, the parties agree as follows:

         SECTION 1. Purchase and Sale of the Mortgage Loans.

         (a) Pursuant to the terms hereof and upon satisfaction of the
conditions set forth herein, the Seller agrees to sell and the Purchaser agrees
to purchase, Mortgage Loans having the general characteristics set forth in this
Agreement and specifically identified on the Mortgage Loan Schedule, for the
Purchase Price set forth below in Section 3(a) hereof and having an aggregate
principal balance on and as of the date of such Mortgage Loan Schedule (the
"Cut-Off Date") of approximately $237,316,463.23 after deduction of principal
payments due on or before the Cut-Off Date (which amount may vary plus or minus
5% thereof), or such other aggregate principal balance as agreed by the
Purchaser and the Seller as evidenced by the actual aggregate principal balance
of the Mortgage Loans accepted by the Purchaser on the Closing Date (as defined
below).

         (b) Subject to mutual agreement between the Purchaser and the Seller,
the closing for the purchase and sale of the Mortgage Loans shall take place on
April 27, 2001 (the "Closing Date") at the office of Purchaser's counsel in
Chicago, Illinois or such other place as the parties shall agree.

         SECTION 2. Mortgage Loan Schedule. Attached to this Agreement as
Schedule 1 is a listing of the Mortgage Loans evidenced by promissory notes,
mortgage notes or other evidence of indebtedness (the "Mortgage Notes")
evidencing the indebtedness of an obligor (the "Mortgagor") under the mortgages,
deeds of trust or other instruments securing a Mortgage Loan (the "Mortgages")
to be purchased by and delivered to the Purchaser on the Closing Date (as such
may be amended prior to the Closing Date by mutual agreement of the parties)
(the "Mortgage Loan Schedule"). The "Mortgage Loan Schedule" as of the Closing
Date shall refer to the Mortgage Loan Schedule as delivered on the Cut-Off Date
related to such Mortgage Loans to be purchased by or on behalf of the Purchaser
pursuant to the terms of this Agreement. The Mortgage Loan Schedule shall
contain as to each Mortgage Loan listed thereon, at a minimum, the Mortgage Loan
information indicated on Schedule 2 hereto.


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         SECTION 3. Purchase Price.

         (a) In exchange for the Mortgage Loans, on the Closing Date, the
Purchaser shall transfer to the Seller by wire transfer in immediately available
funds the purchase price (the "Purchase Price") which is equal to the sum of (a)
the product of 101.119952% and the principal balance thereof as of the Cut-Off
Date and (b) interest on the principal balance of the Mortgage Loans as of the
Cut-Off Date at the Pass-Through Rate from the Cut-Off Date through the day
prior to the Closing Date. With respect to each Mortgage Loan, the "Pass-Through
Rate" shall be the mortgage interest rate on such Mortgage Loan less the per
annum servicing fee payable to the Seller pursuant to the Pooling Agreement (as
defined below).

         (b) The Purchaser shall be entitled to all scheduled payments of
principal and interest due with respect to the Mortgage Loans after the Cut-Off
Date, and all other recoveries of principal and interest collected after the
Cut-Off Date (other than in respect of principal and interest on the Mortgage
Loans due on or before the Cut-Off Date). The Seller shall be entitled to all
scheduled payments of principal and interest due with respect to the Mortgage
Loans on or before the Cut-Off Date, and all other recoveries of principal and
interest collected on or before the Cut-Off Date (other than in respect of
principal and interest on the Mortgage Loans due after the Cut-Off Date). The
principal balance of each Mortgage Loan as of the Cut-Off Date is determined
after deduction of payments of principal due on or before the Cut-Off Date
whether or not collected. Therefore, payments of scheduled principal and
interest prepaid for a date due following the Cut-Off Date shall not be deducted
from the principal balance as of the Cut-Off Date but such prepaid amounts shall
belong to and be promptly remitted to the Purchaser.

         SECTION 4. Examination of Mortgage Files.

         Prior to the Closing Date, the Seller will have made files for each
Mortgage Loan, that consist at least of the documents listed on Schedule 3
attached hereto (with respect to each Mortgage Loan, a "Mortgage File", and
collectively, the "Mortgage Files"), available to the Purchaser or its agents,
for examination at the Seller's offices or such other location as shall
otherwise be agreed upon by the Purchaser and the Seller. The Purchaser may
purchase all or part of the Mortgage Loans with or without conducting any
partial or complete examination. The fact that the Purchaser or its agents have
conducted or have failed to conduct any partial or complete examination of the
Mortgage Files shall not affect the Purchaser's rights under this Agreement,
including, but not limited to, the rights to demand repurchase, substitution or
other relief as provided in this Agreement.

         SECTION 5.    Transfer of Mortgage Loans; Possession of Mortgage Files.

         (a) On the Closing Date, subject to the satisfaction of the terms and
conditions hereof, the Seller shall sell, transfer, assign, set over and
otherwise convey to the Purchaser, without recourse, but subject to the terms of
this Agreement, all right, title and interest of the Seller in and to the
Mortgage Loans and all proceeds thereof, wherever located, including without
limitation, all amounts in respect of principal and interest received or
receivable with respect to Mortgage Loan



                                       -2-

<PAGE>

payments due after the Cut-Off Date (and including scheduled payments of
principal and interest due after the Cut-Off Date but received by the Seller on
or before the Cut-Off Date, but not including payments of principal and interest
due on the Mortgage Loans on or before the Cut-Off Date), together with the
proceeds of any related mortgage insurance policies. Such transfer shall be made
directly to the Purchaser in accordance with the letter delivered to the Seller
by the Purchaser attached hereto as Exhibit A (the "Instruction Letter"). The
Seller's records will accurately reflect the sale of each Mortgage Loan to the
Purchaser.

         (b) The ownership of each Mortgage Loan and the related Mortgage Note,
the Mortgage and the contents of the related Mortgage File shall be, upon
satisfaction of subsection 5(a) hereof, vested in the Purchaser and the
ownership of all records and documents with respect to such Mortgage Loan
prepared by or which come into the possession of the Seller shall immediately
vest in the Purchaser and shall be retained and maintained by the Seller at the
will and for the benefit of the Purchaser in a custodial capacity only. The
Seller shall deliver to the Purchaser or its agent in accordance with the
instructions set forth in Exhibit A, simultaneously with the execution and
delivery of this Agreement or prior to the Closing Date, all of the documents
pertaining to each Mortgage Loan previously delivered to the Seller by ABN AMRO
Mortgage Group, Inc. ("AAMGI") pursuant to that certain Mortgage Loan Purchase
Agreement, dated as of April 17, 2001, between the Seller, as purchaser, and
AAMGI, as seller.

         (c) The transfer of the Mortgage Loans as described herein shall be
absolute and is intended by the parties to be a sale. In the event that a court
deems the conveyance set forth herein not to constitute a sale, the Seller shall
have granted to the Purchaser a first priority security interest in the Mortgage
Loans and in the proceeds thereof of any kind or nature whatsoever, and in the
proceeds of any related insurance policies, subject to the satisfaction or
waiver of the conditions set forth in Section 11 hereof, and shall take, or
shall cause to have been taken, all steps necessary prior to the Closing Date to
perfect such security interest in the Purchaser.

         SECTION 6. Books and Records.

         On the Closing Date, following the sale of the Mortgage Loans to the
Purchaser, title to each Mortgage and the related Mortgage Note shall be
transferred to the Purchaser or its assignee in accordance with this Agreement.
All rights arising out of the Mortgage Loans after the Cut-Off Date including,
but not limited to, any and all funds received on or in connection with a
Mortgage Loan and due after the Cut-Off Date shall be received and held by the
Seller in a custodial capacity for the benefit of the Purchaser or its assignee
as the owner of the Mortgage Loans in accordance herewith and shall be delivered
or caused to be delivered by the Seller to the Purchaser or its assignee on or
immediately following the Closing Date. Any funds received by the Seller or the
Purchaser after the Cut-Off Date but due prior to the Cut-Off Date shall remain
the property of the Seller and shall be promptly remitted to the Seller. As
additional consideration for the Mortgage Loans, the Purchaser shall enter into,
and shall cause State Street Bank and Trust Company, as trustee, to enter into,
a Pooling and Servicing Agreement (the "Pooling Agreement") with the Seller,
which Pooling Agreement shall be reasonably satisfactory to the Seller in form
and substance, pursuant to which



                                       -3-

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the Seller shall have the right to service each Mortgage Loan for a servicing
fee ranging from 0.29% to 0.99% per annum, with a weighted average of 0.7895%
per annum. The Pooling Agreement shall be executed simultaneously with the
execution of this Agreement.

         SECTION 7. Further Actions; Financing Statements.

         (a) In furtherance of the provisions of Section 5(c) hereof, the Seller
agrees to take or cause to be taken such further actions to execute, deliver and
file or cause to be executed, delivered and filed, such further documents and
instruments (including, without limitation, any UCC financing statements) as the
Purchaser may reasonably request, in order to perfect and maintain the security
interest created pursuant to said section and to otherwise fully effectuate the
purposes, terms and conditions of this Agreement, and the Purchaser shall
cooperate in any such action.

         (b) The Seller shall: (i) promptly execute, deliver, and file any
financing statements, amendments, continuation statements, assignments,
certificates and other documents with respect to such security interest as the
Purchaser may reasonably request to perfect or to maintain the perfection of
such security interest, each in form and substance satisfactory to the
Purchaser; and (ii) notify the Purchaser within five (5) days after the
occurrence of any of the following: (A) any change in the Seller's corporate
name or any trade name; (B) any change in the Seller's location of its chief
executive office or principal place of business; and (C) any merger or
consolidation or other change in Seller's identity or material change in its
corporate structure.

         SECTION 8. Representations, Warranties and Agreements of Seller.

         (a) The Seller hereby represents and warrants to the Purchaser as of
the Closing Date (or such other date as is specified in the related
representation or warranty) as follows:

                  (i) The Seller has been duly created and is validly existing
         as a corporation under the laws of the State of Delaware;

                  (ii) The execution and delivery of this Agreement by the
         Seller and its performance of and compliance with the terms of this
         Agreement will not violate the Seller's charter or by-laws or 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 Seller is a party or by which the Seller or to which any of
         the property or assets of the Seller is subject;

                  (iii) This Agreement, assuming due authorization, execution
         and delivery by the Purchaser, constitutes a valid and legally binding
         obligation of the Seller, enforceable against the Seller in accordance
         with its 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;



                                       -4-

<PAGE>



                  (iv) The Seller 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 Seller or its properties or
         might have consequences that would affect its performance hereunder;

                  (v) No litigation is pending or, to the best of the Seller's
         knowledge, threatened against the Seller which would prohibit its
         entering into this Agreement or performing its obligations under this
         Agreement;

                  (vi) The consummation of the transactions contemplated by this
         Agreement are in the ordinary course of business of the Seller, and the
         transfer, assignment and conveyance of the Mortgage Notes and the
         Mortgages by the Seller pursuant to this Agreement is not subject to
         the bulk transfer or any similar statutory provisions in effect in the
         State of Illinois;

                  (vii) With respect to each Mortgage Loan:

                           (a) that the information set forth in the Mortgage
                  Loan Schedule appearing as an exhibit to this Agreement is
                  true and correct in all material respects at the date or dates
                  respecting which such information is furnished as specified
                  therein;

                           (b) the Seller is the sole owner and holder of each
                  Mortgage Loan free and clear of all liens, pledges, charges or
                  security interests of any nature and has full right and
                  authority, subject to no interest or participation of, or
                  agreement with, any other party, to sell and assign the same;

                           (c) no payment of principal of or interest on or in
                  respect of any Mortgage Loan is 30 days or more past due from
                  the Due Date of such payment;

                           (d) to the best of the Seller's knowledge, as of the
                  date of the transfer of the Mortgage Loans to the Purchaser,
                  there is no valid offset, defense or counterclaim to any
                  Mortgage Note or Mortgage;

                           (e) there is no proceeding pending, or to the best of
                  the Seller's knowledge, threatened for the total or partial
                  condemnation of any of the real property, together with any
                  improvements thereto, securing the indebtedness of the
                  Mortgagor under the related Mortgage Loan (the "Mortgaged
                  Property") and the Mortgaged Property is free of material
                  damage and is in good repair and neither the Mortgaged
                  Property nor any improvement located on or being part of the
                  Mortgaged Property is in violation of any applicable zoning
                  law or regulation;



                                       -5-

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                           (f) that each Mortgage Loan complies in all material
                  respects with applicable state or federal laws, regulations
                  and other requirements, pertaining to usury, equal credit
                  opportunity and disclosure laws, and each Mortgage Loan was
                  not usurious at the time of origination;

                           (g) to the best of the Seller's knowledge, all
                  insurance premiums previously due and owing with respect to
                  each Mortgaged Property have been paid and all taxes and
                  governmental assessments previously due and owing, and which
                  may become a lien against the Mortgaged Property, with respect
                  to the Mortgaged Property have been paid;

                           (h) that each Mortgage Note and the related Mortgage
                  are genuine and each is the legal, valid and binding
                  obligation of the maker thereof, enforceable in accordance
                  with its terms except as such enforcement may be limited by
                  bankruptcy, insolvency, reorganization or other similar laws
                  affecting the enforcement of creditors' rights generally and
                  by general equity principles (regardless of whether such
                  enforcement is considered in a proceeding in equity or at
                  law); all parties to the Mortgage Note and the Mortgage had
                  legal capacity to execute the Mortgage Note and the Mortgage;
                  and each Mortgage Note and Mortgage have been duly and
                  properly executed by the Mortgagor;

                           (i) that each Mortgage is a valid and enforceable
                  first lien on the property securing the related Mortgage Note,
                  and that each Mortgage Loan is covered by an ALTA mortgagee
                  title insurance policy or other form of policy or insurance
                  generally acceptable to FNMA or FHLMC, issued by, and is a
                  valid and binding obligation of, a title insurer acceptable to
                  FNMA or FHLMC insuring the originator, its successor and
                  assigns, as to the lien of the Mortgage in the original
                  principal amount of the Mortgage Loan subject only to (a) the
                  lien of current real property taxes and assessments not yet
                  due and payable, (b) covenants, conditions and restrictions,
                  rights of way, easements and other matters of public record as
                  of the date of recording of such Mortgage acceptable to
                  mortgage lending institutions in the area in which the
                  Mortgaged Property is located or specifically referred to in
                  the appraisal performed in connection with the origination of
                  the related Mortgage Loan and (c) such other matters to which
                  like properties are commonly subject which do not
                  individually, or in the aggregate, materially interfere with
                  the benefits of the security intended to be provided by the
                  Mortgage;

                           (j) neither the Seller nor any prior holder of any
                  Mortgage has, except as the Mortgage File may reflect,
                  modified the Mortgage in any material respect; satisfied,
                  cancelled or subordinated such Mortgage in whole or in part;
                  released such Mortgaged Property in whole or in part from the
                  lien of the Mortgage; or executed any instrument of release,
                  cancellation, modification or satisfaction;



                                       -6-

<PAGE>

                           (k) that each Mortgaged Property consists of a fee
                  simple estate or condominium form of ownership in real
                  property;

                           (l) the condominium projects that include the
                  condominiums that are the subject of any condominium loan are
                  generally acceptable to FNMA or FHLMC;

                           (m) no foreclosure action is threatened or has been
                  commenced (except for the filing of any notice of default)
                  with respect to the Mortgage Loan; and except for payment
                  delinquencies not in excess of 30 days, to the best of the
                  Seller's knowledge, there is no default, breach, violation or
                  event of acceleration existing under the Mortgage or the
                  related Mortgage Note and no event which, with the passage of
                  time or with notice and the expiration of any grace or cure
                  period, would constitute a default, breach, violation or event
                  of acceleration; and the Seller has not waived any default,
                  breach, violation or event of acceleration;

                           (n) that each Mortgage Loan was originated on FNMA or
                  FHLMC uniform instruments for the state in which the Mortgaged
                  Property is located;

                           (o) that based upon a representation by each
                  Mortgagor at the time of origination or assumption of the
                  applicable Mortgage Loan, 100% of the Mortgage Loans
                  measured by principal balance were to be secured by
                  owner-occupied residences and 0% of the Mortgage Loans
                  measured by principal balance were to be secured by
                  non-owner-occupied residences;

                           (p) that an appraisal of each Mortgaged Property was
                  conducted at the time of origination of the related Mortgage
                  Loan, and that each such appraisal was conducted in accordance
                  with FNMA or FHLMC criteria, on FNMA or FHLMC forms and
                  comparables on at least three properties were obtained;

                           (q) that no Mortgage Loan had a Loan-to-Value Ratio
                  at origination in excess of 95%;

                           (r) the Mortgage Loans were not selected in a manner
                  to adversely affect the interests of the Purchaser and the
                  Seller knows of no conditions which reasonably would cause it
                  to expect any Mortgage Loan to become delinquent or otherwise
                  lose value;

                           (s) each Mortgage Loan was either (A) originated
                  directly by or closed in the name of either: (i) a savings and
                  loan association, savings bank, commercial bank, credit union,
                  insurance company, or similar institution which is supervised
                  and examined by a federal or state authority or (ii) a
                  mortgagee approved by the Secretary of Housing and Urban
                  Development pursuant to Sections 203



                                       -7-

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                  and 211 of the National Housing Act or (B) originated or
                  underwritten by an entity employing underwriting standards
                  consistent with the underwriting standards of an institution
                  as described in subclause (A)(i) or (A)(ii) above;

                           (t) each Mortgage Loan is a "qualified mortgage"
                  within the meaning of Section 860G of the Internal Revenue
                  Code of 1986, without regard to ss.1.860 G-2(f) of the REMIC
                  provisions or any similar rule;

                           (u) each Mortgage Loan that has a Loan-to-Value Ratio
                  at origination in excess of 80% is covered by a primary
                  mortgage insurance policy; and

                           (v) that no Mortgage Loan permits negative
                  amortization or the deferral of accrued interest.

                  It is understood and agreed that the representations and
         warranties set forth in this Section 8 shall survive the sale of the
         Mortgage Loans to the Purchaser and shall inure to the benefit of the
         Purchaser, notwithstanding any restrictive or qualified endorsement on
         any Mortgage Note (or lost note affidavit and indemnity) or assignment
         of Mortgage or the examination of any Mortgage File.

                  Upon discovery by either the Seller, the Purchaser or its
         designees of a breach of any of the foregoing representations or
         warranties of the Seller which materially and adversely affects (1) the
         value of any of the Mortgage Loans actually delivered or (2) the
         interests of the Purchaser therein, the party discovering such breach
         shall give prompt written notice to the other. Within 90 (ninety) days
         of its discovery or its receipt of notice of any such breach of a
         representation or warranty, the Seller shall, with respect to the
         Mortgage Loan(s) to which such breach relates, either (i) cure such
         breach in all material respects, (ii) repurchase such Mortgage Loan or
         Mortgage Loans (or any property acquired in respect thereof) from the
         Purchaser at the Purchase Price, as adjusted for the then current
         principal balance or (iii) within the 90 (ninety)-day period following
         the Closing Date substitute another mortgage loan for such Mortgage
         Loan. Such substitute mortgage loan shall on the date of substitution,
         (a) have a principal balance not in excess of the principal balance of
         the defective Mortgage Loan, (b) be accruing interest at a rate of
         interest at least equal to that of the defective Mortgage Loan, (c)
         have a remaining term to stated maturity not greater than, and not more
         than two years less than, that of the Mortgage Loan so substituted, (d)
         have an original loan-to-value ratio not higher than that of the
         Mortgage Loan so substituted and a current loan-to-value ratio not
         higher than that of the Mortgage Loan so substituted, and (e) comply
         with all the representations and warranties relating to Mortgage Loans
         set forth herein, as of the date of substitution (such mortgage loan
         being referred to herein as a "Qualifying Substitute Mortgage Loan").
         Except as set forth in Section 12 hereof, it is understood and agreed
         that the obligations of the Seller set forth in this Section 8 to cure,
         substitute for or repurchase a defective Mortgage Loan constitute the
         sole remedies of the Purchaser respecting a breach of the foregoing
         representations and warranties.



                                       -8-

<PAGE>

                  The Purchaser, upon receipt by it of the full amount of the
         then current principal balance for a Mortgage Loan that is repurchased,
         or upon receipt of the Mortgage File for a Qualifying Substitute
         Mortgage Loan for a Mortgage Loan that is substituted or repurchased,
         shall release or cause to be released and reassign to the Seller the
         related Mortgage File for the Mortgage Loan that is substituted and
         shall execute and deliver such instruments of transfer or assignment,
         in each case without recourse, representation, or warranty, as shall be
         necessary to vest in the Seller or its designee or assignee title to
         any such substituted Mortgage Loan released pursuant hereto or Mortgage
         Loan purchased pursuant hereto, free and clear of all security
         interests, liens and other encumbrances, which instruments shall be
         prepared by the Seller at its expense and shall be reasonably
         acceptable to the Purchaser, and the Purchaser shall have no further
         responsibility with respect to the Mortgage File relating to such
         Mortgage Loan that is substituted.

                  Any cause of action against the Seller or relating to or
         arising out of the breach of any representations and warranties made in
         this Section 8 shall accrue as to any Mortgage Loan upon (i) discovery
         of such breach by the Purchaser or notice thereof by the Seller to the
         Purchaser, (ii) failure by the Seller to cure such breach, repurchase
         such Mortgage Loan or substitute a Qualifying Substitute Mortgage Loan
         as specified above, and (iii) demand upon the Seller by the Purchaser
         for all amounts payable in respect of such Mortgage Loan.

         SECTION 9. Representations, Warranties and Agreements of Purchaser.

         (a) The Purchaser hereby represents and warrants to the Seller, as of
the date hereof (or such other date as is specified in the related
representation or warranty) as follows:

                  (i) The Purchaser is a corporation duly formed and validly
         existing under the laws of the State of Delaware;

                  (ii) The execution and delivery of this Agreement by the
         Purchaser and its performance of and compliance with the terms of this
         Agreement will not violate the Purchaser's corporate charter or by-laws
         or 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 Purchaser is a party or by which the Purchaser or to which
         any property or assets of the Purchaser is subject;

                  (iii) This Agreement, assuming due authorization, execution
         and delivery by the Seller, constitutes a valid and legally binding
         obligation of the Purchaser, enforceable against the Purchaser in
         accordance with its 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;



                                       -9-

<PAGE>

                  (iv) The Purchaser 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 the Purchaser
         default might have consequences that would materially and adversely
         affect the condition (financial or other) or operations of the
         Purchaser or its properties or might have consequences that would
         affect its performance hereunder; and

                  (v) No litigation is pending or, to the best of the
         Purchaser's knowledge, threatened against the Purchaser which would
         prohibit its entering into this Agreement or performing its obligations
         under this Agreement;

         SECTION 10. Purchaser's Conditions to Closing. The obligations of the
Purchaser under this Agreement shall be subject to the satisfaction, on or prior
to the Closing Date, of the following conditions:

         (a) The obligations of the Seller required to be performed by it on or
prior to the Closing Date pursuant to the terms of this Agreement shall have
been duly performed and complied with and all of the representations and
warranties of the Seller under this Agreement shall be true and correct as of
the date hereof and as of the Closing Date, and no event shall have occurred
which, with notice or the passage of time, or both, would constitute a default
under this Agreement, and the Purchaser shall have received a certificate to
that effect signed by an Authorized Officer (as defined below) of the Seller.

         (b) The Purchaser or the Purchaser's document custodian shall have
received, or the Purchaser's attorney shall have received in escrow, all of the
following closing documents, in such forms as are agreed upon and acceptable to
the Purchaser, duly executed by all signatories other than the Purchaser, as
required pursuant to the respective terms thereof:

                  (i) An assignment or assignments of the Mortgage Loans to the
         Purchaser or its designee substantially in the form attached hereto as
         Exhibit B with such changes as are required to adapt the assignment to
         the proper form in the jurisdiction where the related Mortgage Property
         is located, and each original Mortgage Note (or lost note affidavit and
         indemnity), duly endorsed originally or by facsimile, without recourse,
         to            , in each case in accordance with the instructions set
         forth in Exhibit A attached hereto, which assignment or assignments and
         Mortgage Note (or lost note affidavit and indemnity) shall be delivered
         to and held by the Purchaser or its agent on behalf of the Purchaser;

                  (ii) The Mortgage Loan Schedule prepared by the Seller dated
         as of the related Closing Date and attached hereto;

                  (iii) A certificate signed by an officer, which officer may be
         either a senior vice president, a vice president, an assistant vice
         president or assistant secretary (an "Authorized Officer"), dated as of
         the Closing Date, substantially in the form attached hereto as Exhibit
         C, to the parties hereto, and attached thereto copies of the charter
         and by-laws and a Good


                                      -10-

<PAGE>


         Standing Certificate or a memorandum setting forth the verbal
         assurances from the appropriate regulatory authorities with respect to
         the Seller will be immediately forthcoming; and

                  (iv) An opinion of Seller's counsel in substantially the form
         attached hereto as Exhibit D.

                  (v) A security release certification, in a form acceptable to
         the Purchaser, executed by the appropriate mortgagee or secured party,
         if any of the Mortgage Loans have at any time been subject to any
         security interest, pledge or hypothecation for the benefit of such
         person.

         (c) The Seller will furnish to the Purchaser such other certificates of
its officers or others and such other documents to evidence fulfillment of the
conditions set forth in this Agreement as the Purchaser and its attorney may
reasonably request.

         SECTION 11. Seller's Conditions to Closing. The obligations of the
Seller under this Agreement shall be subject to the satisfaction, on or prior to
the Closing Date, of the following conditions:

         (a) The obligations of the Purchaser required to be performed by it on
or prior to the Closing Date pursuant to the terms of this Agreement shall have
been duly performed and complied with and all of the representations and
warranties of the Purchaser under this Agreement shall be true and correct as of
the date hereof and as of the Closing Date, and no event shall have occurred
which, with notice or the passage of time, or both, would constitute a default
under this Agreement, and the Seller shall have received a certificate to that
effect signed by an Authorized Officer of the Purchaser;

         (b) The Seller shall have received, or the Seller's attorney shall have
received in escrow, a certificate signed by an Authorized Officer of the
Purchaser dated as of the Closing Date, in the form acceptable to the parties
hereto, and attached thereto the resolutions of the Purchaser authorizing the
transactions contemplated by this Agreement, together with copies of the
Articles of Association and by-laws as of a recent date with respect to the
Purchaser; and

         (c) The Purchaser will furnish to the Seller such other certificates of
its officers or others and such other documents to evidence fulfillment of the
conditions set forth in this Agreement as the Seller and its attorney may
reasonably request.

         SECTION 12. Indemnification.

         (a) The Seller agrees to indemnify and hold harmless the Purchaser
against any and all losses, claims, expenses, damages or liabilities to which
Purchaser may become subject, insofar as such losses, claims, expenses, damages
or liabilities (or actions in respect thereof) arise out of or are



                                      -11-

<PAGE>


based upon any representation or warranty made by the Seller in Section 8(a)(i)
through Section 8(a)(vi) hereof on which Purchaser has relied, being, or alleged
to be, materially untrue or incorrect. This indemnity will be in addition to any
liability which the Seller may otherwise have.

         (b) The Purchaser agrees to indemnify and hold harmless the Seller
solely in its capacity as seller of the Mortgage Loans against any and all
losses, claims, expenses, damages or liabilities to which the Seller may become
subject, insofar as such losses, claims, expenses, damages or liabilities (or
actions in respect thereof) arise out of or are based upon any representation or
warranty made by the Purchaser in Section 9 hereof on which the Seller has
relied, being, or alleged to be, materially untrue or incorrect (notwithstanding
the Purchaser's lack of knowledge with respect to the substance of any
representation or warranty to which Section 9 applies which is made to the best
of the Purchaser's knowledge). This indemnity will be in addition to any
liability which the Purchaser may otherwise have.

         (c) Promptly after receipt by either the Purchasers or the Seller of
notice of the commencement of any action or proceeding in any way relating to or
arising from this Agreement, such party will notify the other party of the
commencement thereof; but the omission so to notify the party from whom
indemnification is sought (the "Indemnifying Party") will not relieve the
Indemnifying Party from any liability which it may have to the party seeking
indemnification (the "Indemnified Party") except to the extent that the
Indemnifying Party is adversely affected by the lack of notice. In case any such
action is brought against the Indemnified Party, and it notifies the
Indemnifying Party of the commencement thereof, the Indemnifying Party will be
entitled to participate in the defense (with the consent of the Indemnified
Party which shall not be unreasonably withheld) of such action at the
Indemnifying Party's expense.

         SECTION 13. Notices. All demands, notices and communications hereunder
shall be in writing and shall be deemed to have been duly given if mailed, by
registered or certified mail, return receipt requested, or, if by other means,
when received by the other party. Notices to the Seller shall be directed to
Washington Mutual Mortgage Securities Corp., 75 North Fairway Drive, Vernon
Hills, Illinois 60061, Attention: Legal Services Department; and notices to the
Purchaser shall be directed to ABN AMRO Mortgage Corporation, 181 West Madison
Street, Suite 3250, Chicago, Illinois 60602, Attention: Maria Fregosi - First
Vice President - ABN AMRO Mortgage Operations, with a copy to ABN AMRO North
America, Inc., 135 South LaSalle Street, Chicago, Illinois 60603, Attention:
Kirk Flores - Associate General Counsel; or such other addresses as may
hereafter be furnished to the other party by like notice.

         SECTION 14. Termination. This Agreement may be terminated (a) by the
mutual consent of the parties hereto, or (b) by the Purchaser if the conditions
to the Purchaser's obligations to closing set forth under Section 10 hereof are
not fulfilled as and when required to be fulfilled or (c) by the Seller if the
Purchaser's obligations under Section 11 hereof are not fulfilled as and when
required. In the event of a termination pursuant to Section 14(b), the Seller
agrees that it will pay the out-of-pocket fees and expenses of the Purchaser in
connection with the transactions contemplated by this Agreement and in the event
of a termination pursuant to Section 14(c), the Purchaser agrees that it



                                      -12-

<PAGE>


will pay the out-of-pocket fees and expenses of the Seller in connection with
the transactions contemplated by this Agreement.

         SECTION 15. Representations, Warranties and Agreements to Survive
Delivery. All representations, warranties and agreements contained in this
Agreement, or in certificates of officers of the Seller and the Purchaser
submitted pursuant hereto, shall remain operative and in full force and effect
and shall survive transfer and sale of the Mortgage Loans to the Purchaser.

         SECTION 16. Severability. If any provision of this Agreement shall be
prohibited or invalid under applicable law, the Agreement shall be ineffective
only to such extent, without invalidating the remainder of this Agreement.

         SECTION 17. Counterparts. This Agreement may be executed in any number
of counterparts, each of which shall be an original, but both of which together
shall constitute one and the same agreement.

         SECTION 18. Governing Law. This Agreement shall be deemed to have been
made in the State of New York and shall be interpreted in accordance with the
laws of such state without regard to the principles of conflicts of law of such
state.

         SECTION 19. Further Assurances. The Seller and the Purchaser agree to
execute and deliver such instruments and take such actions as the other party
may, from time to time, reasonably request in order to effectuate the purpose
and to carry out the terms of this Agreement.

         SECTION 20. Successors and Assigns. This Agreement shall be binding
upon and inure to the benefit of and be enforceable by the Seller and the
Purchaser and their permitted successors and assigns. The Seller acknowledges
and agrees that the Purchaser may assign its rights under this Agreement. Any
person into which the Seller may be merged or consolidated (or any person
resulting from any merger or consolidation involving the Seller), or any person
succeeding to the business of the Seller shall be considered the "successor" of
the Seller hereunder. Except as provided in the two preceding sentences, this
Agreement cannot be assigned, pledged or hypothecated by any party hereto
without the written consent of the other party to this Agreement.
Notwithstanding anything to the contrary in this Section 20, the parties hereto
agree that the Purchaser has the right to assign its rights and interest in, to
and under Section 8 hereof.

         SECTION 21. Amendments. No term or provision of this Agreement may be
waived or modified unless such waiver or modification is in writing and signed
by a duly authorized officer of the party against whom such waiver or
modification is sought to be enforced.



                                      -13-

<PAGE>

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


                                    Washington Mutual Mortgage Securities Corp.,
                                    as Seller


                                    By:/s/ Michael L. Parker
                                       ---------------------------------------
                                    Name: Michael L. Parker
                                    Title: President




                                      -14-
                                                Mortgage Loan Purchase Agreement

<PAGE>



                                    ABN AMRO Mortgage Corporation,
                                    as Purchaser


                                    By: /s/ Daniel J. Fischer
                                       ---------------------------------------
                                    Name:    Daniel J. Fischer
                                    Title:   Vice President




                                      -15-
                                                Mortgage Loan Purchase Agreement

<PAGE>



                                   SCHEDULE 1

                             MORTGAGE LOAN SCHEDULE

A copy of the Mortgage Loan Schedule may be obtained by contacting the
Registrant.





                                      -16-

<PAGE>

                                   SCHEDULE 2

                       MORTGAGE LOAN SCHEDULE INFORMATION

       Each Mortgage Loan shall be identified by at least the following details,
among others, relating to each Mortgage Loan:

         (i)      the loan number of the Mortgage Loan and name of the related
                  Mortgagor;

         (ii)     the street address of the Mortgaged Property including city,
                  state and zip code;

         (iii)    the mortgage interest rate as of the Cut-Off Date;

         (iv)     the original term and maturity date of the related Mortgage
                  Note;

         (v)      the original principal balance;

         (vi)     the first payment date;

         (vii)    the monthly payment in effect as of the Cut-Off Date;

         (viii)   the date of the last paid installment of interest;

         (ix)     the unpaid principal balance as of the close of business on
                  the Cut-Off Date;

         (x)      the loan-to-value ratio at origination and as of the Cut-Off
                  Date;

         (xi)     the type of property and the Original Value (as defined in the
                  Pooling and Servicing Agreement) of the Mortgaged Property;

         (xii)    whether a primary mortgage insurance policy is in effect as of
                  the Cut-Off Date;

         (xiii)   the nature of occupancy at origination;

         (xiv)    the county in which the Mortgaged Property is located, if
                  available; and

         (xv)     the Closing Date.



                                      -17-

<PAGE>

                                   SCHEDULE 3

                            MORTGAGE FILE INFORMATION


         Each Mortgage File shall include at least the following documents,
among others, with respect to each Mortgage Loan transferred and assigned from
the Seller to the Purchaser, or its agent:

         (i)      the original Mortgage Note (or, if the original Mortgage Note
                  has been lost or destroyed, a lost note affidavit and
                  indemnity) bearing all intervening endorsements endorsed, "Pay
                  to the order of               , without recourse" and signed
                  in the name of the mortgagee at the request of the Seller by
                  an Authorized Officer showing an unbroken chain of title from
                  the originator thereof to the person endorsing;

         (ii)     (a) the original Mortgage with evidence of recording thereon,
                  and if the Mortgage was executed pursuant to a power of
                  attorney, a certified true copy of the power of attorney
                  certified by the recorder's office, with evidence of recording
                  thereon, or certified by a title insurance company or escrow
                  company to be a true copy thereof; provided, that if such
                  original Mortgage or power of attorney cannot be delivered
                  with evidence of recording thereon on or prior to the Closing
                  Date because of a delay caused by the public recording office
                  where such original Mortgage has been delivered for
                  recordation or because such original Mortgage has been lost,
                  the Seller shall deliver or cause to be delivered to the
                  Purchaser (with a copy to the Trustee (as defined in the
                  Pooling and Servicing Agreement)) a true and correct copy of
                  such Mortgage, together with (1) in the case of a delay caused
                  by the public recording office, a certificate signed by an
                  Authorized Officer of the Seller stating that such original
                  Mortgage has been dispatched to the appropriate public
                  recording official for recordation or (2) in the case of an
                  original Mortgage that has been lost, a certificate by the
                  appropriate county recording office where such Mortgage is
                  recorded or from a title insurance company or escrow company
                  indicating that such original was lost and the copy of the
                  original mortgage is a true and correct copy;

                  (b) the original assignment to "State Street Bank and Trust
                  Company, as Trustee," which assignment shall be in form and
                  substance acceptable for recording, or a copy certified by the
                  Seller as a true and correct copy of the original assignment
                  which has been sent for recordation. Subject to the foregoing,
                  such assignments may, if permitted by law, be by blanket
                  assignments for Mortgage Loans covering Mortgaged Properties
                  situated within the same county. If the assignment is in
                  blanket form, a copy of the assignment shall be included in
                  the related individual Mortgage File;

         (iii)    the originals of any and all instruments that modify the terms
                  and conditions of the Mortgage Note, including but not limited
                  to modification, consolidation, extension



<PAGE>

                  and assumption agreements including any adjustable rate
                  mortgage (ARM) rider, if any;

         (iv)     the originals of all required intervening assignments, if any,
                  with evidence of recording thereon, and if such assignment was
                  executed pursuant to a power of attorney, a certified true
                  copy of the power of attorney certified by the recorder's
                  office, with evidence of recording thereon, or certified by a
                  title insurance company or escrow company to be a true copy
                  thereof; provided, that if such original -------- assignment
                  or power of attorney cannot be delivered with evidence of
                  recording thereon on or prior to the Closing Date because of a
                  delay caused by the public recording office where such
                  original assignment has been delivered for recordation or
                  because such original assignment has been lost, the Seller
                  shall deliver or cause to be delivered to the Purchaser (with
                  a copy to the Trustee (as defined in the Pooling and Servicing
                  Agreement)) a true and correct copy of such assignment,
                  together with (a) in the case of a delay caused by the public
                  recording office, a certificate signed by an Authorized
                  Officer of the Seller stating that such original assignment
                  has been dispatched to the appropriate public recording
                  official for recordation or (b) in the case of an original
                  assignment that has been lost, a certificate by the
                  appropriate county recording office where such assignment is
                  recorded or from a title insurance company or escrow company
                  indicating that such original was lost and the copy of the
                  original assignment is a true and correct copy;

         (v)      the original mortgagee policy of title insurance (including,
                  if applicable, the endorsement relating to the negative
                  amortization of the Mortgage Loans) or in the event such
                  original title policy is unavailable, any one of an original
                  title binder, an original preliminary title report or an
                  original title commitment or a copy thereof certified by the
                  title company with the original policy of title insurance to
                  follow within 180 days of the Closing Date;

         (vi)     the mortgage insurance certificate;

         (vii)    hazard insurance certificates and copies of the Hazard
                  Insurance Policy and, if applicable, flood insurance policy;
                  and

         (viii)   any and all other documents, opinions and certificates
                  executed and/or delivered by the related Mortgagor and/or its
                  counsel in connection with the origination of such Mortgage
                  Loan, which may include truth-in-lending statements and other
                  legal statements, and appraisal and a survey.



                                       -2-

<PAGE>

                                    EXHIBIT A

                               INSTRUCTION LETTER

                          ABN AMRO Mortgage Corporation
                       181 West Madison Street, Suite 3250
                             Chicago, Illinois 60602


                                                               ________ __, 2001


Washington Mutual Mortgage Securities Corp.
75 North Fairway Drive
Vernon Hills, Illinois 60061

Dear Ladies and Gentlemen:

         Pursuant to the Mortgage Loan Purchase Agreement dated as of April 27,
2001 (the "Purchase Agreement") between you and us, we have agreed to purchase
from you certain Mortgage Loans. All capitalized terms used herein and not
otherwise defined shall have the meanings set forth in the Purchase Agreement.

         In order to facilitate these transactions, and for the purpose of
convenience only, we hereby authorize and direct you to:

<TABLE>
<CAPTION>
Action                                                           Due Date
<S>                                                             <C>
1.       Endorse mortgage notes (or lost note affidavits         on or before the Closing Date
         and indemnities) to:
         "Pay to the order of
         __________________ without recourse"


2.       Assign mortgages to be recorded                         on or before the Closing Date
         to State Street Bank and Trust Company, as
         Trustee:

3.       Deliver or caused to be delivered to the Purchaser      two business days after funding
         or its agent a Mortgage File for each Mortgage
         Loan

4.       Provide lost mortgage note affidavits, certified        on or before the Closing Date
         copies of all missing mortgages, and certified
</TABLE>


<PAGE>

<TABLE>
<S>                                                             <C>
         recorded copies of missing intervening
         assignments

5.       Mortgage Loan Schedule generated by Seller and          one day prior to funding
         agreed to by Purchaser
</TABLE>


                                            Sincerely,

                                            ABN AMRO Mortgage Corporation


                                            By:
                                               ---------------------------------
                                            Name:
                                                 -------------------------------
                                            Title:
                                                  ------------------------------





                                       -2-

<PAGE>


                                    EXHIBIT B


                               FORM OF ASSIGNMENT


         Washington Mutual Mortgage Securities Corp., a Delaware corporation
(the "Seller"), in exchange for $           in hand paid and other good and
valuable consideration, hereby grants, bargains, sells, assigns, transfers,
conveys, and sets over to ABN AMRO Mortgage Corporation, a Delaware corporation
(the "Purchaser"), all of the Seller's right, title, and interest in, to, and
under the mortgage loans listed on Schedule 1 attached hereto, the mortgage
notes evidencing or relating to such mortgage loans, all mortgages, trust deeds,
title insurance policies, property insurance policies, chattel paper, loan
guaranties, loan accounts, surveys, instruments, certificates, and other
documents whatsoever evidencing or relating to such mortgage notes and mortgage
loans, and all books, ledgers, books of account, records, writings, data bases,
information, and computer software (and all documentation therefor or relating
thereto, and all licenses relating to or covering such computer software and/or
documentation), and all other property, rights, title, and interests whatsoever
relating to, used, or useful in connection with, or evidencing, embodying,
incorporating, or referring to, any of the foregoing (the "Mortgages"). The
Seller warrants to the Purchaser that the Seller is the owner of the Mortgages,
subject to no liens, claims, or encumbrances.




<PAGE>



Dated:  _____________, 2001          Washington Mutual Mortgage Securities Corp.


                                     By:
                                        ---------------------------------
                                     Name:
                                          -------------------------------
                                     Title:
                                           ------------------------------





                                       -2-

<PAGE>



ACKNOWLEDGED ON __________ __, 2001

ABN AMRO Mortgage Corporation


By:
   -------------------------------------
  Name:
       ---------------------------------
  Title:
        --------------------------------





                                       -3-

<PAGE>



STATE OF       ____________          )
                                     )
COUNTY OF      ____________          )


         I, ______________, a Notary Public in and for the said County and
State, do hereby certify that ____________, personally known to me to be the
same person whose name is subscribed to the foregoing instrument as
_______________ of __________________, appeared before me this day in person
and, being first sworn, acknowledged that he signed and delivered the said
instrument as his own free and voluntary act, and as the free and voluntary act
of said corporation as the ___________ of ____________, a ____________, for the
uses and purposes therein set forth and that he was duly authorized to execute
the said instrument by the __________________ of said ________________.

         Given under my hand and seal, this ____ day of ____________, 2001.



                                      ----------------------------------
                                      Notary Public

                                      My commission expires:
                                                            --------------------




                                       -4-

<PAGE>



                                    EXHIBIT C

                          FORM OF OFFICER'S CERTIFICATE

                   Washington Mutual Mortgage Securities Corp.

         I, ____________________, do hereby certify pursuant to Section 10(a)
and (b)(iii) of the Purchase Agreement (as hereinafter defined) that I am the
duly elected ____________________ of Washington Mutual Mortgage Securities Corp.
("WAMU" ), a Delaware corporation, and further certify as follows:

         1. Attached hereto as Exhibit "A" is a true and correct copy of the
articles of incorporation of WAMU. There has been no amendment or other document
filed affecting the charter as of the date of this certification of WAMU, and no
such amendment has been authorized.

         2. Attached hereto as Exhibit "B" is a true and correct copy of the
by-laws of WAMU as in full force and effect as of the date of this
certification.

         3. No proceedings looking toward merger, consolidation, liquidation, or
dissolution of WAMU are pending or contemplated.

         4. Each person who, as an officer or representative of WAMU, signed, or
will sign (a) the Purchase Agreement, and (b) any other document delivered
pursuant thereto or on the date hereof in connection with the Mortgage Loan
Purchase Agreement, dated as of April 27, 2001, between WAMU, as seller, and ABN
AMRO Mortgage Corporation, as Purchaser (the "Purchase Agreement") was, at the
respective times of such signing and delivery, and is as of the date hereof duly
elected or appointed, qualified and acting as such officer or representative,
and the signatures of such persons appearing on such documents are their genuine
signatures.

         5. Attached hereto as Exhibit "C" is a true, complete and correct copy
of the Resolutions of WAMU's Board of Directors, which were duly adopted as of
_____ __, ____, and such Resolutions have not been amended, altered or repealed,
and remain in full force and effect without modification on the date hereof.

         6. Attached hereto as Exhibit "D" is a Good Standing Certificate issued
by the Office of the Secretary of State of Delaware as of __________, ____. A
current Good Standing Certificate has been requested from the Office of the
Secretary of State of _________ and will be supplied when it is received.

         7. WAMU has performed all obligations and satisfied all conditions on
its part to be performed or satisfied under the Purchase Agreement on or prior
to the Closing Date and all of the representations and warranties of the Seller
under the Purchase Agreement are true and correct as of the date hereof and as
of the Closing Date, and no event has occurred which, with notice or passage of
time, or both, would constitute a default under the Purchase Agreement.


<PAGE>

All capitalized terms used herein and not otherwise defined shall have the
meanings set forth in the Purchase Agreement.

IN WITNESS WHEREOF, I have hereunto signed my name.

Date:    __________ __, ____


                                     Washington Mutual Mortgage Securities Corp.



                                     By:
                                        ----------------------------------------
                                     Name:
                                          --------------------------------------
                                     Title:
                                           -------------------------------------





                                       -2-

<PAGE>



         I, ____________________, __________________________ of Washington
Mutual Mortgage Securities Corp., a Delaware corporation, hereby certify that
____________________ is the duly elected, qualified and acting
____________________ of Washington Mutual Mortgage Securities Corp. and that the
signature appearing on the preceding page is his genuine signature.
         IN WITNESS WHEREOF, I have hereunto signed my name.
Date:    __________ __, ____


                                     Washington Mutual Mortgage Securities Corp.



                                     By:
                                        ----------------------------------------
                                     Name:
                                          --------------------------------------
                                     Title:
                                           -------------------------------------




                                       -3-

<PAGE>

                    [OPINION TO BE REVISED IN ACCORDANCE WITH
                    GENERAL COUNSEL'S FORM OF OPINION LETTER]


                                    Exhibit D

                      [OPINION OF SELLER'S IN-HOUSE COUNSEL
                         PURSUANT TO SECTION 10(B)(IV)]



                                                __________ __, 2001



ABN AMRO Mortgage Corporation
181 West Madison Street, Suite 3250
Chicago, Illinois 60602

         Re: ABN AMRO Mortgage Corporation Purchase of Mortgage Loans

Ladies and Gentlemen:

         As General Counsel to Washington Mutual Mortgage Securities Corp., a
Delaware Corporation ("Seller"), I and attorneys working under my supervision
have acted as counsel to Seller in connection with the sale of Mortgage Loans by
Seller to ABN AMRO Mortgage Corporation (the "Purchaser") pursuant to a Mortgage
Loan Purchase Agreement, dated as of April 27, 2001 (the "Purchase Agreement"),
between the Purchaser and Seller. This opinion is being delivered to the
Purchaser pursuant to Section 10(b)(iv) of the Purchase Agreement. All
capitalized terms not otherwise defined herein have the meanings given them in
the Purchase Agreement.

         In rendering the opinions set forth below, we have examined and relied
upon originals or copies, certified or otherwise identified to our satisfaction,
of the charter and by-laws of Seller, the Purchase Agreement and such corporate
records, agreements or other instruments of Seller, and such certificates,
records and other documents, agreements and instruments, including, among other
things, certain documents delivered on the Closing Date, as we have deemed
necessary and proper as the basis for our opinions. In connection with such
examination, we have assumed the genuineness of all signatures, the authenticity
of all documents, agreements and instruments submitted to us as originals, the
conformity to original documents, agreements and instruments of all documents,
agreements and instruments submitted to us as copies or specimens, the
authenticity of the originals of such documents, agreements and instruments
submitted to us as copies or specimens, the conformity to executed original
documents of all documents submitted to us in draft and the accuracy of the
matters set forth in the documents we reviewed. We have also assumed that all
documents, agreements and instruments have been duly authorized, executed and
delivered by all parties thereto. As to any facts material to such opinions that
we did not independently establish




<PAGE>


ABN AMRO Mortgage Corporation
__________ __, 200_
Page 2


or verify, we have relied upon statements and representations of officers and
other representatives of Seller as we have deemed necessary and proper as the
basis for our opinions, including, among other things, the representations and
warranties of Seller in the Purchase Agreement.

         Based upon the foregoing, I am of the opinion that:

         1. Seller is a ______________, duly organized, validly existing and in
good standing under the laws of _____________ and either is not required to be
qualified to do business under the laws of any states where such qualification
is necessary to transact the business contemplated by the Purchase Agreement, or
is qualified to do business under the laws of any states where such
qualification is necessary to transact the business contemplated by the Purchase
Agreement, and Seller is duly authorized and has full corporate power and
authority to transact the business contemplated by the Purchase Agreement.

         2. The Purchase Agreement has been duly authorized, executed and
delivered by Seller and is a legal, valid and binding obligation of and is
enforceable against Seller in accordance with its terms, except that the
enforceability thereof may be subject to (A) bankruptcy, insolvency,
receivership, conservatorship, reorganization, moratorium or other laws, now or
hereafter in effect, relating to creditors' rights generally, (B) general
principles of equity (regardless of whether enforcement is sought in a
proceeding in equity or at law) and (C) limitations of public policy under
applicable securities laws as to rights of indemnity and contribution under the
Purchase Agreement.

         3. No consent, approval, authorization or order of any court or
supervisory, regulatory, administrative or governmental agency or body is
required for the execution, delivery and performance by Seller of or compliance
by Seller with the Purchase Agreement, the sale of the Mortgage Loans or the
consummation of the transactions contemplated by the Purchase Agreement.

         4. Neither the execution and delivery by Seller of the Purchase
Agreement, nor the consummation by Seller of the transactions contemplated
therein, nor the compliance by Seller with the provisions thereof, will conflict
with or result in a breach of any of the terms, conditions or provisions of
Seller's charter or by-laws or board or shareholder's resolutions, or any
agreement or instrument to which Seller is now a party or by which it is bound,
or constitute a default or result in an acceleration under any of the foregoing,
or result in the violation of any law, rule, regulation, order, judgment or
decree to which Seller or its property is subject, which, in any of the above
cases, would materially and adversely affect Seller's ability to perform its
obligations under the Purchase Agreement.

         5. There is not an action, suit, proceeding or investigation pending,
or, to the best of my knowledge, threatened against Seller which, either in any
one instance or in the aggregate, would


<PAGE>


ABN AMRO Mortgage Corporation
__________ __, 200_
Page 3

draw into question the validity of the Purchase Agreement or the Mortgage Loans
or of any action taken or to be taken in connection with the obligations of
Seller contemplated therein, or which would be likely to materially impair the
ability of Seller to perform under the terms of the Purchase Agreement.

         The Opinions expressed herein are limited to matters of federal and
_____________ law and do not purport to cover any matters as to which laws of
any other jurisdiction are applicable. Except as expressly provided herein, this
opinion is being furnished to you solely for your benefit in connection with the
purchase of the Mortgage Loans, and it is not to be used, circulated, quoted or
otherwise referred to for any purpose without my express written consent.


                                    Sincerely,

                                    Washington Mutual Mortgage Securities Corp.


                                    By:
                                       -------------------------------------
                                    Title:  General Counsel