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                                                                  EXECUTION COPY

                                                                     EXHIBIT 2.1

          Joint Purchase Agreement (this "AGREEMENT"), dated as of January ____,
2002, among Westfield America Limited Partnership, a Delaware limited
partnership ("WALLABY"), Simon Property Group, L.P., a Delaware limited
partnership ("HOOSIER"), and The Rouse Company, a Maryland corporation
("TERRAPIN").

                              W I T N E S S E T H:
                              - - - - - - - - - -

          WHEREAS, simultaneously with the signing of this Agreement, Wallaby,
Westfield Growth, LP, Hoosier, Hoosier Acquisition, LLC, Terrapin and Terrapin
Acquisition LLC are entering into the Purchase Agreement (as the same may be
amended from time to time in accordance with the terms hereof and thereof, the
"PURCHASE AGREEMENT") and the Protocol (as defined in the Purchase Agreement)
pursuant to which they agreed to purchase substantially all the assets of
Rodamco North America, N.V., an investment company with variable capital,
incorporated under the laws of The Netherlands ("TARGET"); and

          WHEREAS, Wallaby, Hoosier and Terrapin desire to set forth certain
agreements relating to their rights and obligations under the Purchase
Agreement.

          NOW, THEREFORE, in order to induce each other to enter into the
Purchase Agreement and in consideration of the premises and the mutual
agreements and covenants hereinafter set forth, Wallaby, Hoosier and Terrapin
hereby agree as follows:

                                    ARTICLE I

                                  DEFINED TERMS

          1.01 DEFINED TERMS. Capitalized terms used herein without definition
shall have the meanings ascribed to them in the Purchase Agreement. In addition,
the following terms shall have the meanings ascribed thereto in this Section
1.01:

          (a)  "ASSETS TO BE SOLD" means the properties or assets reflected on
the Master Schedule under the heading "Assets to be Sold."

          (b)  "DEFAULT PERCENTAGE" means the Gross Asset Value of the
Purchaser/Target JV Assets that a Non-Purchasing Party is required to purchase
pursuant to Section 3.02(c), divided by the Gross Asset Value of all of the
Assets of Target and the Target Subsidiaries to be purchased under the Purchase
Agreement (including any Assets to be Sold that have not been sold by Target (or
the applicable Target Subsidiary) prior to the Closing, Three Party Assets and
properties and assets that are allocated to the

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Purchasing Party(ies)). As of the date of this Agreement, the Gross Asset Value
of all of the Assets of Target and the Target Subsidiaries to be purchased is
$5,438,205,000.

          (c)  "GP" means Head Acquisition, L.P., a Delaware limited
partnership.

          (d)  "GROSS ASSET VALUE" means, with respect to each property or
asset, the amount listed under the heading "RNA Share of Gross Asset Value" on
the Master Schedule. For purposes of Section 2.02(d) only, "Gross Asset Value"
shall be the amount set forth on the Master Schedule attached hereto as EXHIBIT
A and shall not be recalculated prior to the Closing. For all purposes of this
Agreement, "Gross Asset Value" does not include the amount of any indebtedness
with respect to any Asset to be Sold other than River Ridge, South Square and
745 Fifth Avenue.

          (e)  "HOOSIER ASSETS" means the properties or assets reflected on the
Master Schedule under the heading of "Simon Assets".

          (f)  "JOINTLY OWNED ALLOCATED ASSETS" means any Wallaby Asset, Hoosier
Asset or Terrapin Asset that is jointly owned by the parties in accordance with
the principles set forth in this Agreement or as otherwise agreed to by all of
the Purchasers.

          (g)  "MASTER SCHEDULE" means the "Master Schedule" attached hereto as
EXHIBIT A, as the same may be revised (i) from time to time, (A) to take into
account properties or assets becoming Three Party Assets pursuant to Section
2.02(d) hereof, (B) any change in the allocation of a property or asset in
accordance with Section 3.02(c) or Section 3.02(e), or (C) as agreed to by all
of the Purchasers, and (ii) immediately prior to Closing, in accordance with the
methodologies employed in preparing the Master Schedule attached to this
Agreement to reflect changes in equity, debt, the amount of unallocated
indebtedness of Target and Target Subsidiaries that is to be repaid at the
Closing (as determined in accordance with Section 2.02(c) and as set forth on
the Master Schedule under "Share of Corporate Debt" (under the heading
"Allocation of Value")), RNA ownership and interest rates used to determine
entries in the Master Schedule, except that no changes shall be made to "cap
rates" and NOI in the calculations of the updated Master Schedule. (All
revisions to the Master Schedule pursuant to clause (ii) of this definition
shall require the approval of all of the Purchasers, which approval will not be
unreasonably withheld, conditioned or delayed so long as the proposed revisions
are consistent with the provisions of clause (ii). Notwithstanding the
foregoing, if the pending ground rent dispute with respect to San Francisco
Centre is resolved prior to the Closing, the NOI reflected in the Master
Schedule with respect to San Francisco Centre will be revised to reflect such
resolution.)

          Each party hereby acknowledges and agrees that the entries in the
Master Schedule are relevant solely for purposes of determining their respective
aggregate obligations under the Purchase Agreement and under this Agreement.
However, each

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party may have valued each of the assets or properties allocated to it at an
amount different from that set forth in the Master Schedule and the Master
Schedule shall not be an admission as to the valuation of any property or asset.

          (h)  "MINIMUM PRICE" shall have the meaning set forth in a schedule to
be agreed to by all of Wallaby, Hoosier and Terrapin.

          (i)  "PERCENTAGE INTEREST" means 43.359% (in the case of Wallaby),
29.315% (in the case of Hoosier) and 27.326% (in the case of Terrapin), in each
case, as shown on the Master Schedule attached hereto as EXHIBIT A as of the
date of this Agreement. The Purchaser's respective Percentage Interests will be
revised from time to time based on changes to the Master Schedule made in
accordance with the terms hereof.

          (j)  "PURCHASER/TARGET JV ASSET" means (i) Garden State Plaza, with
respect to Wallaby, (ii) Coral Square, Miami International, West Town Mall and
Florida Mall, with respect to Hoosier, and (iii) Collin Creek, Perimeter Mall
and Willowbrook, with respect to Terrapin.

          (k)  "TERRAPIN ASSETS" means the properties or assets reflected on the
Master Schedule under the heading of "Rouse Assets".

          (l)  "THREE PARTY ASSETS" means the properties or assets reflected on
the Master Schedule under the heading "Three Party Assets", together with any
other Assets (other than the Wallaby Assets, the Hoosier Assets, the Terrapin
Assets and the Assets to be Sold) to which Purchasers are entitled (and
purchase) under the Purchase Agreement.

          (m)  "URBAN OP" means Urban Shopping Centers, L.P., an Illinois
limited partnership.

          (n)  "URBAN RETAIL" means Urban Retail Properties Co.

          (o)  "WALLABY ASSETS" means the properties or assets reflected on the
Master Schedule under the heading of "Westfield Assets".

                                   ARTICLE II

                                   THE ASSETS

          2.01 ALLOCATION OF ASSETS; PURCHASE PRICE.

          (a)  Subject to the terms and conditions of the Purchase Agreement,
Wallaby, Hoosier and Terrapin agree that (i) Hoosier (or one or more of its
designees) shall purchase the Hoosier Assets; (ii) Terrapin (or one or more of
its designees) shall purchase the Terrapin Assets; (iii) Wallaby (or one or more
of its designees) shall

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purchase the Wallaby Assets; and (iv) the Three Party Assets and the Assets to
be Sold shall be purchased by Wallaby, Hoosier and Terrapin (or one or more of
their respective affiliates) through the GP or as otherwise agreed to by all of
the Purchasers). The aggregate cash purchase price shall be determined in
accordance with the Purchase Agreement and, at the Closing, the amounts payable
by each of Wallaby, Hoosier and Terrapin, as the case may be, shall be an amount
equal to (A) such Purchaser's "Share of Cash Consideration to RNA Shareholders"
(as set forth on the Master Schedule) plus (B) such party's Percentage Interest
in any and all other amounts payable by Purchasers pursuant to the Purchase
Agreement (including, without limitation, the Additional Amount, if any, and any
amounts payable as of the Closing Date pursuant to Section 5.7(a) of the
Purchase Agreement). For purposes of illustration, if the Master Schedule as of
the Closing Date is identical to the Master Schedule attached hereto as EXHIBIT
A and the Purchasers were obligated to pay an additional $50,000,000 pursuant to
clause (B), then (x) Wallaby would be required to pay the euro ((euro))
equivalent of $975,112,000 plus $21,679,500 (i.e. 43.359% of $50,000,000), (y)
Hoosier would be required to pay the euro ((euro)) equivalent of $715,517,000
plus $14,657,500 (i.e. 29.315% of $50,000,000), (z) Terrapin would be required
to pay the euro ((euro)) equivalent of $541,432,000 plus $13,663,000 (i.e.
27.326% of $50,000,000). All such amounts shall be paid in cash by each of
Wallaby, Hoosier and Terrapin in euros to the extent required by the Purchase
Agreement. To the extent currency fluctuation results in an increase or decrease
in the amounts payable under the Purchase Agreement relating to the allocations
based on dollars (U.S.) in the Master Schedule, then the obligation of each of
Wallaby, Hoosier and Terrapin to pay its portion of the purchase price in euros
shall be increased or decreased under this Section 2.01(a) to reflect such
currency fluctuation.

          (b)  If a direct or indirect transfer of any property or asset
identified as a Wallaby Asset, a Hoosier Asset or a Terrapin Asset to Wallaby
(or its designee(s)), Hoosier (or its designee(s)) or Terrapin (or its
designee(s)), as the case may be, is determined not to be the most efficient
structure for the transaction or cannot be accomplished based on existing
contractual limitations, then Wallaby, Hoosier and Terrapin shall cooperate in
arranging the sale or other transfer of ownership of such property or asset, or
of the entity owned by Target which directly or indirectly owns the relevant
property or asset, to the party which otherwise would have purchased the
property or asset. However, if such entity is to own properties and/or assets
allocated to two or more of Wallaby, Terrapin and Hoosier, then such properties
and/or assets shall be jointly owned by an entity created in accordance with
this Agreement or as otherwise agreed to by the affected Purchasers. It is
currently expected that an arrangement of the type described in this Section
2.01(b) will be required with respect to the properties and other assets of the
Urban OP, the Three Party Assets and any of the Assets to be Sold that are not
sold by Target prior to the Closing. Wallaby, Hoosier and Terrapin (or their
designees) shall contribute cash for the purchase of any such entity in the
manner described in this Agreement or as otherwise agreed to by all of the
Purchasers prior to the Closing. Wallaby, Hoosier and Terrapin shall cooperate
in establishing the structure of

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such jointly owned entities in order to avoid unnecessary expense and to
minimize any adverse financial or tax consequences of these entities.

          (c)  Wallaby, Hoosier and Terrapin shall use their reasonable best
efforts to sell the Assets to be Sold as soon as practicable, in accordance with
the provisions of the Purchase Agreement. Wallaby, Hoosier and Terrapin shall
consult and cooperate with one another in connection with the sale of the Assets
to be Sold, and in determining the terms and conditions of the sale contracts
with respect to the Assets to be Sold. The consent of all of Wallaby, Hoosier
and Terrapin shall be required for any agreement to sell an Assets to be Sold;
provided, however, that the parties agree that, following the completion of the
marketing program agreed upon by the Purchasers and subject to the terms of the
Purchase Agreement, any Asset to be Sold may be sold to a third party that is
not affiliated with any of the Purchasers at the request of any of Wallaby,
Hoosier or Terrapin at a cash price equal to at least 95% of the Minimum Price
regardless of the objections of any other Purchaser(s). In the event that more
than one Purchaser desires to invoke the immediately preceding sentence, a
majority of the Purchasers shall determine the collective actions to be taken by
the Purchasers. In the event that an Asset to be Sold is sold to a third party
after the Closing, the net proceeds from such sale shall be distributed to
Wallaby, Hoosier and Terrapin (or shall reduce their obligation to fund their
cash purchase price, if the sale is completed prior to the Closing), based on
their respective Percentage Interests. Decisions regarding brokers and similar
matters relating to the process by which purchasers are solicited for any Asset
to be Sold shall require the consent of any two of Wallaby, Hoosier and
Terrapin.

          2.02 LIABILITIES; TRANSFER TAXES; REPAYMENT OF DEBT; REDEMPTION OF
URBAN PREFERRED; DAMAGED ASSETS; INTANGIBLE ASSETS; OTHER MATTERS.

          (a)  ASSUMPTION OF LIABILITIES; ALLOCATION OF LIABILITIES; TRANSFER
TAXES. Wallaby (or its designee(s)) shall assume (or take subject to) all
liabilities and obligations specifically related to the Wallaby Assets
(including mortgage and secured debt), Terrapin (or its designee(s)) shall
assume (or take subject to) all liabilities and obligations specifically related
to the Terrapin Assets (including mortgage and secured debt) and Hoosier (or its
designee(s)) shall assume (or take subject to) all liabilities and obligations
specifically related to the Hoosier Assets (including mortgage and secured debt)
(all such liabilities and obligations, "ASSET SPECIFIC LIABILITIES"). For
purposes of this Section 2.02(a), all interest rate swaps, caps, treasury locks
and other derivatives and hedges shall be allocated to the debt to which these
instruments or arrangements relate and the costs of unwinding these instruments
or arrangements shall be borne in accordance with this allocation. Transfer
taxes, transfer fees, lender consent fees and other similar amounts payable to
third parties in connection with the transfer of any property or asset pursuant
to the Purchase Agreement shall be allocated to the party to whom such property
or asset is allocated regardless of whether that property or asset is acquired
by such party directly or is held as a Jointly Owned Allocated Asset.

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          (b)  UNALLOCATED LIABILITIES. Except as set forth in this Agreement,
liabilities under the Purchase Agreement which are not Asset Specific
Liabilities shall be assumed or paid at the Closing based on the Percentage
Interests of Wallaby, Hoosier and Terrapin. These liabilities shall include the
obligations of Purchasers under Section 5.11 of the Purchase Agreement and debt
issued by Target or any Target Subsidiary that is not an Asset Specific
Liability to the extent not repaid by Target on or prior to the Closing.
Obligations under Section 5.7 of the Purchase Agreement shall be allocated to
Wallaby, Hoosier or Terrapin in accordance with their Percentage Interests
except to the extent that employees are clearly allocable solely to a Wallaby
Asset, a Hoosier Asset or a Terrapin Asset, in which case, Wallaby, Hoosier or
Terrapin, as appropriate, shall assume such obligation.

          (c)  REPAYMENT OF UNALLOCATED DEBT AT CLOSING. If the Purchasers
unanimously elect, or are required by one or more third parties, to repay at the
Closing any indebtedness of Target or any Target Subsidiary (other than Asset
Specific Liabilities, which shall be the sole and exclusive responsibility of
the party to which the property or asset in question has been allocated), at the
Closing, each of Wallaby, Hoosier and Terrapin shall pay in cash its Percentage
Interest of the indebtedness to be repaid. For these purposes, "indebtedness"
shall be deemed to include the costs of unwinding any interest rate swaps, caps,
treasury locks and other derivatives and hedges associated with the indebtedness
that is being repaid. Each of Wallaby, Hoosier and Terrapin hereby acknowledges
and agrees that the indebtedness described on Exhibit B attached hereto will be
repaid by the Purchasers in connection with the Closing. Any Non-Purchasing
Party (as defined in Section 3.02(b)) shall, without duplication of amounts
required to be paid pursuant to Section 3.02(c), pay in cash at the Closing its
Default Percentage multiplied by the aggregate amount of the indebtedness to be
repaid in accordance with this Section 2.02(c).

          (d)  CONVERSION OF DAMAGED ASSETS TO THREE PARTY ASSETS. If any
Wallaby Asset, Terrapin Asset or Hoosier Asset suffers Damages (as defined
below) prior to the Closing, but the Purchasers are obligated to consummate the
transactions contemplated by the Purchase Agreement, then, at the election of
the Purchaser to which the damaged property or asset has been allocated, such
damaged property or asset shall be purchased as a Three Party Asset with each of
Wallaby, Hoosier and Terrapin contributing to the purchase price for such
property or asset in proportion to their respective Percentage Interests (as
adjusted to reflect the operation of this Section 2.02(d)). "Damages" shall mean
a change in the value of a property or asset of at least 5% of the Gross Asset
Value with respect to such property or asset to the extent not covered by
insurance, including casualty loss, claims or obligations relating to
environmental or tax liability, and litigation unrelated to tenants, employees
or the operation of such property or asset consistent with current use, but
shall exclude changes resulting from (i) tenant bankruptcies, changes in
occupancy rates, changes in rent rolls in the ordinary course of Target's
business (as opposed to inaccuracies in Target's representations or warranties
in the Purchase Agreement with respect to the Rent Rolls),

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or collectability of rents associated with that property or asset, (ii) general
changes in the economy or financial markets in the United States or any region
outside the United States, (iii) changes in Law that affect real estate
investment trusts generally, unless such changes have a materially
disproportionate effect relative to other properties or assets, and (iv) changes
that affect the retail industry or retail real estate properties generally,
unless such changes have a disproportionate effect relative to the other
properties or assets. In no event (y) will "Damages" include, or be deemed to
include, any change in the NOI of San Francisco Centre that results from the
resolution of the pending ground rent dispute with the ground lessor, and (z)
will Wallaby be entitled to convert San Francisco Centre to a Three Party Asset
as a result of such dispute or the resolution thereof.

          2.03 INTANGIBLE PROPERTY. All trademarks, service marks, trade dress,
logos, trade names and corporate names, whether or not registered, including all
common law rights thereto, and registrations and applications for registration
thereof, and all other intangible property relating to an property or asset
shall become the property of the party acquiring the property or asset. Prior to
the Closing, the parties will identify any intangible property, such as
management information systems, which may be used in connection with more than
one property or asset, and will enter into a mutually satisfactory agreement for
the joint use of such property.

          2.04 OTHER ASSET-RELATED MATTERS.

          (a)  TERMINATION OF PROPERTY MANAGEMENT AGREEMENTS. To the extent
permitted under agreements with third parties, as soon as reasonably practicable
after the Closing, if requested by a party to whom a specific property or asset
has been allocated (i.e. a Wallaby Asset, a Hoosier Asset or a Terrapin Asset),
the parties shall cooperate so that the existing management agreements relating
to such property or asset shall be terminated (without the need for prior notice
or payment of any termination fee) and the party to whom such property or asset
is allocated shall have the right to enter into new management agreements with
such parties as it may choose.

          (b)  ACCOUNTING PRIOR TO CLOSING; CLOSING ADJUSTMENTS. The Purchasers
will endeavor to cause Target and the Target Subsidiaries to account for all
items of income and expense relating to the Wallaby Assets, the Hoosier Assets
and the Terrapin Assets on a property-by-property basis. To the extent not
reflected on the Master Schedule (or the assumptions underlying the entries
therein), all capital expenditures after the date hereof with respect to Wallaby
Assets, Hoosier Assets and Terrapin Assets will be allocated to, and borne by,
the Purchaser to which such asset is allocated. In connection with the Closing,
the Purchasers will make customary closing adjustments with respect to the
Wallaby Assets, the Hoosier Assets and the Terrapin Assets. All such allocations
will be made in a manner to be agreed upon by Wallaby, Hoosier and Terrapin such
that, to the maximum extent practicable, each Purchaser derives the benefits and
bears the burdens (financial or otherwise) of the properties and/or assets that

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have been allocated to it. After the Closing, the Purchasers will make
appropriate payments to one another to reflect any revisions to such closing
adjustments; provided, however, that no such revisions shall be made after March
31, 2003.

                                   ARTICLE III

                           CONSENTS; CERTAIN DECISIONS

          3.01 CONSENTS. All consents, approvals or waivers to be given by the
Purchasers under the Purchase Agreement shall require the consent of all of
Wallaby, Hoosier and Terrapin, in each case in accordance with the provisions of
the Purchase Agreement; provided, however, that any consents, approvals or
waivers that relate exclusively to a Wallaby Asset, a Hoosier Asset or a
Terrapin Asset shall be given by Wallaby, Hoosier or Terrapin, respectively, and
shall not require the consent or approval of the other parties (unless the
liabilities assumed by any non-consenting party would be increased, in which
case, that affected non-consenting party's consent also shall be required). Any
amendment to the Purchase Agreement shall require the consent of all of Wallaby,
Hoosier and Terrapin.

          3.02 CLOSING CONDITIONS.

          (a)  The decision as to whether a condition under Section 7.1 of the
Purchase Agreement shall be waived shall require the consent of all of Wallaby,
Hoosier and Terrapin, except as otherwise set forth herein.

          (b)  Subject to Sections 3.02(c) and 3.02(e) below, if Wallaby,
Hoosier and Terrapin (acting in good faith) do not all agree as to whether a
condition under Section 7.1 of the Purchase Agreement is satisfied or whether a
termination right is available to Purchasers under Article VIII of the Purchase
Agreement, and if the party (or parties) which does not believe that the
condition is satisfied or which believes that such termination right is
available (individually or collectively, as the case may be, the "NON-CONSENTING
PARTY") does not waive such condition or desires to exercise such termination
right, then the Non-Consenting Party shall have the right to terminate the
Purchase Agreement, if and when such termination right is available to the
Purchasers pursuant to Article VIII of the Purchase Agreement provided the
requirements of the following two sentence are satisfied. Each of the Purchasers
hereby agrees that if it desires to terminate the Purchase Contract in
accordance with this Section 3.02(b), such Non-Consenting Party shall
immediately deliver to all of the other Purchasers written notice of its
intention to terminate the Purchase Agreement pursuant to this Section 3.02(b)
(a "SECTION 3.02(b) TERMINATION NOTICE"). If any single Purchaser does not (or
any two Purchasers do not) notify the Non-Consenting Party in writing of its (or
their) election to proceed under Section 3.02(c) (such notice, a "SECTION
3.02(b) NEGATION NOTICE") within five (5) business days (or such shorter period
of time as is (i) reasonable in light of the

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scheduled closing date and the Purchasers' ability to postpone the Closing and
(ii) specified in the Section 3.02(b) Termination Notice) after their receipt of
a Section 3.02(b) Termination Notice, then the Non-Consenting Party will have
the right to terminate the Purchase Agreement.

          The Non-Consenting Party hereby agrees to indemnify and hold harmless
the other parties from all claims by third parties (including, without
limitation, Target) arising out of the termination of the Purchase Agreement by
the Non-Consenting Party. The Non-Consenting Party shall have the right, at its
cost and expense, to defend any such claim and to settle any such claim relating
to or arising out of the termination of the Purchase Agreement. The
Non-Consenting Party shall have full control of the defense against these
claims. If any indemnified party wishes, it may participate at its own cost, but
not control, the defense or settlement of any such claim. The Non-Consenting
Party shall not be liable for any settlement effected without its consent. The
Non-Consenting Party shall not settle any claim unless (i) the terms of such
settlement do not impose any obligations on any indemnified party, (ii) the full
amount of the monetary settlement will be paid by the Non-Consenting Party, and
(iii) each indemnified party receives as part of the settlement a full and
unconditional release of its liabilities with respect to the claim. If the
Non-Consenting Party obtains a judicial determination (which is not subject to
appeal) that there is no liability or other amounts payable to the Target
arising out of the termination of the Purchase Agreement, then each of the other
parties to this Agreement shall reimburse the Non-Consenting Party for the
product of (i) the out-of-pocket expenses of the Non-Consenting Party in
connection with the defense of the claims relating to the termination of the
Purchase Agreement and (ii) such party's Percentage Interest.

          (c)  Except as set forth in this Section 3.02(c) and subject to
Section 3.02(e), if any of the parties is unable or unwilling (including any
unwillingness to waive a condition under Section 7.1 of the Purchase Agreement)
to consummate the transactions contemplated by the Purchase Agreement or if any
of the Purchasers is a Non-Consenting Party (individually or collectively, as
the case may be, the "NON-PURCHASING PARTY), the other parties (individually or
collectively, as the case may be, the "PURCHASING PARTY") shall have the right
to purchase all the Assets of Target as contemplated under the Purchase
Agreement. In that case, (i) except as set forth in this Section 3.02(c), the
Non-Purchasing Party shall be relieved of all of its obligations under this
Agreement and the Purchase Agreement and (ii) the Purchasing Party will
indemnify, defend and hold the Non-Purchasing Party harmless from and against
any and all liability arising from or relating to the Purchase Agreement.

          In the event that such purchase right is exercised by the Purchasing
Party, the Non-Purchasing Party hereby agrees to purchase Target's interests in
the Purchaser/Target JV Asset(s) applicable to such Non-Purchasing Party
simultaneously or as soon as practicable following the consummation of the
transactions contemplated by the Purchase Agreement. In the event the provisions
of this Section 3.02(c) are

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applicable, (i) all of the properties and assets allocated to the Non-Purchasing
Party (other than the applicable Purchaser/Target JV Assets) shall be
reallocated to the Purchasing Party(ies), and the Master Schedule will be
revised to reflect such reallocation; (ii) the Non-Purchasing Party will have no
interest whatsoever in the Assets to be Sold or the Three Party Assets, and the
Master Schedule will be revised to indicate that the Non-Purchasing Party's
"Share of Value in Three Party Assets" and the Non-Purchasing Party's "Share of
Value in Assets to be Sold" are each $0; (iii) the Non-Purchasing Party's
Percentage Interest shall be deemed to equal its Default Percentage, and the
Master Schedule will be revised to reflect the same; (iv) each of the Purchasing
Parties' Percentage Interests will be adjusted to reflect the matters described
in clauses (i) - (iii); and (v) the Non-Purchasing Party shall purchase Target's
interest the applicable Purchaser/Target JV Asset(s) for an amount, payable in
euros ((euro)), calculated in accordance with clause (A) and clause (B) of
Section 2.01(a) and on the basis of the Master Schedule as revised pursuant to
clauses (i) - (iii). In addition, but without duplication of any payment
required pursuant to clause (v) above, the Non-Purchasing Party will also be
required to pay its Percentage Interest (as revised pursuant to clause (iii)
above) of unallocated indebtedness pursuant to Section 2.02(c).

          If the Purchasing Party has exercised its rights under this Section
3.02(c), except to the extent the same relate to the applicable Purchaser/Target
JV Assets, following such exercise, the Non-Purchasing Party will not be
entitled to vote on, consent to or otherwise approve or participate in any
action required to be taken by the Purchasers pursuant to the Purchase Agreement
or this Agreement; provided, however, that neither the Purchase Agreement nor
this Agreement shall be modified or amended in any way that materially increases
the obligations, or materially decreases the rights, of the Non-Purchasing
Party.

          Notwithstanding anything in this Section 3.02(c) to the contrary
(including the immediately preceding paragraph), if Wallaby is the
Non-Purchasing Party, then neither Hoosier nor Terrapin (individually or
collectively) shall consummate the transactions contemplated by the Purchase
Agreement unless at the time of Closing it is reasonably expected that no less
than 51.12 euros per Ordinary Share will be distributed by Target in accordance
with the Protocol.

          (d)  If a party breaches its agreements in this Agreement or the
Purchase Agreement and that breach causes termination of the Purchase Agreement,
the breaching party shall be responsible for all damages resulting from the
termination of the Purchase Agreement and shall indemnify and hold harmless the
non-breaching parties. The indemnifying party shall have the right, at its cost
and expense, to defend any claim and to settle any claim relating to or arising
out of the termination of the Purchase Agreement. The indemnifying party shall
have full control of the defense against these claims. If any indemnified party
wishes, it may participate at its own cost, but not control, the defense or
settlement of any such claim. The indemnifying party shall not be liable for any
settlement effected without its consent. The indemnifying party shall not settle
any claim

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unless (i) the terms of such settlement do not impose any obligations on any
indemnified party, (ii) the full amount of the monetary settlement will be paid
by the indemnifying party, and (iii) each indemnified party receives as part of
the settlement a full and unconditional release of its liabilities with respect
to the claim.

          (e)  Subject to Section 3.01, the decision as to whether a condition
under Section 7.1(e) of the Purchase Agreement shall be waived with respect to
any particular property or asset shall be made solely by the party acquiring the
property or asset (with respect to the property or asset in question, the
"REQUIRED CONSENT PARTY"). With respect to any consents and/or waivers relating
to Rolim Associates or Tishman Hotel & Realty, all of the Purchasers will be
Required Consent Parties. If (i) the Required Consent Party decides not to waive
a condition under Section 7.1(e) of the Purchase Agreement with respect to any
property or asset allocated to it, and (ii) the failure of such condition
entitles the Purchasers to terminate the Purchase Agreement pursuant to Article
VIII thereof, and (iii) the Required Consent Party desires to terminate the
Purchase Agreement, then (y) the Required Consent Party shall immediately
deliver a Section 7.1(e) Termination Notice (as defined below) to all of the
other Purchasers and (z) if the Required Consent Party does not receive a
Negation Notice (as defined below) within five (5) business days (or such
shorter period of time as is (i) reasonable in light of the scheduled closing
date and the Purchasers' ability to postpone the Closing and (ii) specified in
the Section 7.1(e) Termination Notice) after its delivery of such Section 7.1(e)
Termination Notice to all of the other Purchasers, the Required Consent Party
will have the right to terminate the Purchase Agreement.

          As used in this Section 3.02(e), (i) "SECTION 7.1(e) TERMINATION
NOTICE" means a notice delivered by the Required Consent Party which (A)
identifies with specificity the condition under Section 7.1(e) of the Purchase
Agreement that has not been satisfied, (B) identifies the property or asset to
which such condition relates (such property or asset, the "SECTION 7.1(e)
TRIGGER ASSET") and (B) expressly sets forth the Required Consent Party's
irrevocable election to terminate the Purchase Agreement if it does not receive
a Negation Notice from one or both of the other Purchasers within the 5-business
day period (or such shorter period of time as is (i) reasonable in light of the
scheduled closing date and the Purchasers' ability to postpone the Closing and
(ii) specified in the Section 7.1(e) Termination Notice) specified in this
Section 3.02(e), and (ii) "NEGATION NOTICE" means a notice delivered to a
Required Consent Party by one or both of the other Purchasers following its (or
their) receipt of a Section 7.1(e) Termination Notice, which notice sets forth
such Purchaser's irrevocable election to purchase the Section 7.1(e) Trigger
Asset. Upon the Required Consent Party's receipt of a Negation Notice, (i) the
Section 7.1(e) Trigger Asset shall be reallocated to the Purchaser(s) that
delivered such Negation Notice, (ii) the Percentage Interests of such
Purchaser(s) and the Required Consent Party will be adjusted to reflect such
reallocation and (iii) all of the Purchasers shall continue to be bound by the
terms of this Agreement and the Purchase Agreement and obligated to consummate
the transactions contemplated hereby and thereby.

                                       11
<Page>

          3.03 NOTICES. Any notice which any of Wallaby, Terrapin or Hoosier
desires to deliver to Target under the Purchase Agreement shall require the
consent of all of Wallaby, Hoosier and Terrapin (which consent shall not be
unreasonably withheld or delayed), unless a party is expressly authorized to
take action under the terms of this Agreement without the other parties'
consent.

          3.04 JOINT CONTROL; DEFENSE OF SUITS. Subject to the other provisions
of this Agreement (including Sections 3.02(c)), unless related solely to an
property or asset allocated to any of Wallaby, Hoosier or Terrapin, then
Wallaby, Hoosier and Terrapin shall jointly control the defense of any action,
suit or proceeding in connection with, relating to or arising under, the
Purchase Agreement or in connection with any Assets to be Sold or Three Party
Assets which is instituted prior to the Closing Date and no party shall consent
to the settlement or compromise of such action without the prior written consent
of the others (not to be unreasonably withheld, conditioned or delayed). All
losses and expenses in connection with jointly controlled actions, suits or
proceedings in connection with, relating to or arising under, the Purchase
Agreement shall be shared by Wallaby, Hoosier and Terrapin based on their
respective Percentage Interests.

          3.05 MANAGEMENT OF THREE PARTY ASSETS. To the extent that property
management services are required with respect to any Assets to be Sold and/or
any Three Party Assets (including any allocated property that is converted to a
Three Party Asset in accordance with Section 2.02(d)), such services will be
provided by Urban Retail. All consents, approvals, decisions and other actions
with respect to Kravco, Urban Retail and any other Three Party Assets shall
require the approval of all of Wallaby, Hoosier and Terrapin; provided, however,
that any consents, approvals, decisions or other actions that relate exclusively
to a Wallaby Asset, a Hoosier Asset or a Terrapin Asset (including actions taken
by Urban Retail in its capacity as property manager with respect to any such
asset) shall be given or taken by Wallaby, Hoosier or Terrapin, respectively,
and shall not require the consent or approval of the other parties (unless the
liabilities assumed by any other party would be increased, in which case, the
affected party's consent also shall be required).

          3.06 GARDEN STATE CONSENT. Subject to Section 3.08, Wallaby hereby
irrevocably waives (and shall cause any entities it controls to waive) any
rights it may have under Article X of the Amended and Restated Limited
Partnership Agreement of Westland Garden State Plaza Limited Partnership, dated
as of July 1, 1993, among Westland Management, Inc., HRE Garden State Plaza,
Inc. and Westland Partners, Inc. in connection with the sale of the Assets of
Target and the Target Subsidiaries pursuant to the Purchase Agreement and this
Agreement.

          3.07 FRANKLIN PARK CONSENT. Subject to Section 3.08, Terrapin hereby
irrevocably waives (and shall cause any entities it controls to waive) any
rights it may have to consent to, or approve of, the transfer of Target's
interests in Franklin Mall Limited Partnership to Wallaby (or its designee) and
hereby waives any rights of first

                                       12
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offer and/or rights of first refusal to which Terrapin (or any of Terrapin's
affiliates) may be entitled in respect of such transfer in connection with the
sale of the Assets of Target and the Target Subsidiaries pursuant to the
Purchase Agreement and this Agreement.

          3.08 CONSENTS NOT EFFECTIVE IF PURCHASE AGREEMENT IS TERMINATED.
Notwithstanding anything to the contrary contained in this Agreement or in the
Purchase Agreement, if the Purchase Agreement is terminated for any reason
whatsoever, the consents and waivers set forth in Sections 3.06 and 3.07 shall
be null and void and no further force or effect with respect to any transaction
occurring after the termination of the Purchase Agreement.

          3.09 URBAN RETAIL MANAGEMENT OF COMPETITIVE MALLS. In the event that
Urban Retail manages, or proposes to manage, any regional mall (but excluding
any of the Wallaby Assets, Hoosier Assets or Terrapin Assets managed by Urban
Retail) that is located within a ten (10) mile radius of any regional mall that
is owned or controlled, directly or indirectly, or managed by Wallaby, Hoosier
or Terrapin, all decisions relating to Urban Retail's management of such
potentially competitive property and the decision to have Urban Retail manage
such competitive property will require the unanimous consent of Wallaby, Hoosier
and Terrapin. If Urban Retail currently manages any such competitive mall, the
Purchasers will take such reasonable actions as are required to terminate the
management agreement in question in an expeditious manner.

                                   ARTICLE IV

                   EXPENSES; BREAK-UP FEE OR BREAK-UP EXPENSES

          4.01 INDIVIDUAL EXPENSES. Except as otherwise set forth herein, each
party will bear its own expenses, including (i) the fees of its own
investigations into the value and other characteristics of the portfolio of
properties and/or assets being purchased pursuant to the Purchase Agreement;
(ii) the fees of its own professional advisors; (iii) the expenses relating to
each property or asset being acquired by such party, including without
limitation, (a) the cost of any title insurance (for itself or any lender,
including lenders of indebtedness assumed by such party in connection with the
acquisition of such property or asset under the Purchase Agreement), surveys,
title inspections, environmental reports, engineering reports and appraisals
that such party elects to obtain, and (b) the amount of any prepayment premiums
or similar payments required as a result of a prepayment of debt associated with
such property or asset on or prior to the Closing Date.

          4.02 BREAK-UP FEE OR BREAK-UP EXPENSES. If Target pays a Break-up Fee,
Break-up Expenses or Reduced Break-up Expenses pursuant to the Purchase
Agreement, then any amount so paid by Target shall be allocated among the
Purchasers as follows: (i) any Break-up Fee shall be allocated based on the
respective Percentage Interests of

                                       13
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the Purchasers, and (ii) Break-up Expenses or Reduced Break-up Expenses (the
"EXPENSES") shall be allocated based on the respective Percentage Interests of
the Purchasers; provided, however that no Purchaser shall receive more than its
actual out-of-pocket expenses (and any amount by which the Percentage Interest
of a Purchaser multiplied by the Expenses exceeds actual out-of-pocket expenses
of that Purchaser, shall be allocated to the other Purchasers).

                                    ARTICLE V

                                  MISCELLANEOUS

          5.01 NOTICES. Notices to any of Wallaby, Terrapin or Hoosier shall be
given in the manner provided in Section 9.3 of the Purchase Agreement.

          5.02 HEADINGS. The headings contained in this Agreement are for
reference only and shall not affect in any way the meaning or interpretation of
this Agreement.

          5.03 SEVERABILITY. If any term or other provision of this Agreement is
invalid, illegal or incapable of being enforced by any rule of law or public
policy, all other conditions and provisions of this Agreement shall nevertheless
remain in full force and effect so long as the economic or legal substance of
the transactions contemplated hereby is not affected in any manner adverse to
any party. Upon such determination that any term or other provision is invalid,
illegal or incapable of being enforced, the parties hereto shall negotiate in
good faith to modify this Agreement so as to effect the original intent of the
parties as closely as possible in a mutually acceptable manner in order that the
transactions contemplated hereby be consummated as originally contemplated to
the greatest extent possible.

          5.04 CONSULTATION AND COOPERATION. The parties shall consult with each
other in connection with their efforts to consummate the transactions
contemplated by the Purchase Agreement and this Agreement, and shall cooperate,
in reasonable respects, with each other in seeking to effect these transactions
in the most effective and efficient manner.

          5.05 RESERVATION OF RIGHTS. If the Closing does not occur and the
Purchase Agreement is terminated pursuant to the terms thereof, this Agreement,
the Transaction Documents and any other discussions, negotiations or exchanges
relating to the transactions contemplated by the Transaction Documents shall be
with full reservation of rights and none of the Transaction Documents (other
than the Confidentiality Agreements) or any such discussions, negotiations or
exchanges shall be regarded as waiving any rights or claims of any party thereto
in any ruling, litigation or any future claims that are or could be made
relating to the transactions contemplated by

                                       14
<Page>

the Transaction Documents. For purposes of this Section 5.05, "Transaction
Documents" means the "Transaction Documents" (as defined in the Purchase
Agreement), this Agreement and all other agreements between and/or among the
Purchasers with respect to the transactions contemplated by the Purchase
Agreement and/or this Agreement.

          5.06 ENTIRE AGREEMENT. This Agreement constitutes the entire agreement
of the parties hereto with respect to the subject matter hereof and supersedes
all prior agreements and undertakings, both written and oral.

          5.07 ASSIGNMENT. No party may assign this Agreement without the
consent of the other party; provided that a party may assign its rights
hereunder to an affiliate, but no such assignment shall relieve the assignor of
any of its obligations hereunder.

          5.08 NO THIRD-PARTY BENEFICIARIES. This Agreement shall be binding
upon Wallaby, Hoosier and Terrapin and shall inure to the sole benefit of
Wallaby, Hoosier and Terrapin, and their respective successors, heirs, legal
representatives and permitted assigns. Nothing herein, express or implied, is
intended to or shall confer upon any other person or entity any legal or
equitable right, benefit or remedy of any nature whatsoever under or by reason
of this Agreement.

          5.09 AMENDMENT; WAIVER. This Agreement may not be amended or modified
except by an instrument in writing signed by each of Wallaby, Hoosier and
Terrapin.

          5.10 GOVERNING LAW. This Agreement shall be governed by and construed
in accordance with the laws of the State of New York. All actions and
proceedings arising out of or relating to this Agreement shall be heard and
determined in any state or federal court sitting in the City of New York, and
the parties hereto hereby irrevocably submit to the exclusive jurisdiction of
such courts in any such action or proceeding and irrevocably waive the defense
of an inconvenient forum to the maintenance of any such action or proceeding.

          5.11 COUNTERPARTS. This Agreement may be executed in one or more
counterparts, and by the parties hereto in separate counterparts, each of which
when executed shall be deemed to be an original but all of which taken together
shall constitute one and the same agreement.

                                       15
<Page>

          IN WITNESS WHEREOF, Wallaby, Hoosier and Terrapin have caused this
Agreement to be executed as of the date first written above by their respective
officers thereunto duly authorized.

                               WESTFIELD AMERICA LIMITED PARTNERSHIP

                               By: Westfield America, Inc., its general partner

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

                               SIMON PROPERTY GROUP, L.P.

                               By: Simon Property Group, Inc., its general
                                      partner

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

                               THE ROUSE COMPANY

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

                  [Signature Page to Joint Purchase Agreement]

<Page>

                                    EXHIBIT A

                        [Master Schedule to be Attached]