<PAGE>

                         AGREEMENT OF SALE AND PURCHASE

                                     BETWEEN

                          THE BENENSON CAPITAL COMPANY,
                  LAWRENCE A. BENENSON AND RAYMOND E. BENENSON

                                                        SELLER

                                       AND

                          YORK AVENUE DEVELOPMENT, INC.

                                                        PURCHASER

                            DATE: SEPTEMBER 9, 1999

                                    PREMISES:

                                1334 YORK AVENUE
                               NEW YORK, NEW YORK



<PAGE>




                                TABLE OF CONTENTS
<TABLE>
<CAPTION>

<S>                <C>                                                   <C>
ARTICLE I          INCLUSIONS IN SALE AND EXCLUSIONS FROM SALE............1

ARTICLE 2          PURCHASE PRICE.........................................2
ARTICLE 3          REPRESENTATIONS AND WARRANTIES.........................3

ARTICLE 4          STATE OF TITLE OF PROPERTY.............................4

ARTICLE 5          TITLE INSURANCE AND ABILITY OF SELLER TO CONVEY........5

ARTICLE 6          CLOSING COSTS..........................................6

ARTICLE 7          INTENTIONALLY OMITTED..................................6

ARTICLE 8          INTENTIONALLY OMITTED..................................6

ARTICLE 9          ACKNOWLEDGMENTS OF PURCHASER;
                   CONDITION OF PROPERTY..................................7

ARTICLE 10         OPERATIONS PRIOR TO CLOSING............................8

ARTICLE 11         CASUALTY AND EMINENT DOMAIN............................8

ARTICLE 12         INTENTIONALLY OMITTED..................................9

ARTICLE 13         CLOSING ADJUSTMENTS....................................9

ARTICLE 14         CLOSING DOCUMENTS; OBLIGATIONS OF PURCHASER
                   AND SELLER AT CLOSING..................................9

ARTICLE 15         VIOLATIONS............................................11

ARTICLE 16         SALES TAX.............................................11

ARTICLE 17         UNPAID TAXES; LIENS OR ENCUMBRANCES...................12

ARTICLE 18         THE CLOSING...........................................12

ARTICLE 18A        NOTICES...............................................13

ARTICLE 19         DEFAULTS; GUARANTY....................................14


<PAGE>

ARTICLE 20         CONDITIONS; SURVIVAL..................................15

ARTICLE 21         SUCCESSORS AND ASSIGNS................................16

ARTICLE 22         BROKERS...............................................16

ARTICLE 23                 ESCROW........................................17

ARTICLE 24                 MISCELLANEOUS.................................18
</TABLE>


EXHIBITS

Schedule A     -     Description of the Land
Schedule B     -     Permitted Encumbrances
Schedule C     -     FIRPTA Certificates
Schedule D     -     Guaranty of Sotheby's, Inc.


<PAGE>

         AGREEMENT OF SALE AND PURCHASE (this "AGREEMENT") is made and entered
into as of September __, 1999, by and between THE BENENSON CAPITAL COMPANY, a
New York general partnership, having an office at 708 Third Avenue, 28th Floor,
New York, New York 10017, LAWRENCE A. BENENSON, residing at 866 United Nations
Plaza, New York, New York 10312 and RAYMOND E. BENENSON, residing at 1122
Ruffner Road, Niskayuna, New York 12309 (collectively "SELLER"), and YORK AVENUE
DEVELOPMENT, INC., a New York corporation, having an office at 1334 York Avenue,
New York, New York 10021 ("PURCHASER").

                              W I T N E S S E T H :

         Seller hereby agrees to sell and convey to Purchaser, and Purchaser
hereby agrees to purchase from Seller, upon the terms and conditions hereinafter
set forth, the land and the buildings known as and located at 1334 York Avenue,
New York, New York (the "PROPERTY").

         NOW, THEREFORE, in consideration of the premises and of the mutual
covenants and agreements hereinafter set forth, and subject to the terms,
provisions and conditions hereof, Seller and Purchaser hereby covenant and agree
as follows:

                                    ARTICLE I

                   INCLUSIONS IN SALE AND EXCLUSIONS FROM SALE

         1.1      The term "PROPERTY" shall mean the following:

                  1.1.1 The land described on SCHEDULE "A" annexed hereto (the
"LAND").

                  1.1.2 The building, structures and improvements, together with
the tenements, hereditaments and appurtenances thereto belonging or in any way
appertaining, now erected or situate on the Land (collectively, the "BUILDING").

                  1.1.3 All of Seller's right, title and interest, if any, in
and to the fixtures, equipment, machinery and personal property used in
connection with the operation of the Property and owned by Seller and not being
the property of Tenant (as hereinafter defined) or any other party.

                  1.1.4 All right, title and interest of Seller, if any, in and
to any land lying in the bed of any street, road or avenue, opened or proposed,
in front of or adjoining the Land, to the center line thereof, and any strips
and gores adjacent to the Land, and all right, title and interest of Seller, if
any, in and to any award made or to be made in lieu thereof and in and to any
unpaid award for damage to the Land and Building by reason of change of grade of
any street.


                                       1
<PAGE>

                  1.1.5 All of Seller's interest, as lessor, in the lease
between Seller, as lessor, and Sotheby Park Bernet, Inc ("TENANT"),  as lessee,
dated as of July 25, 1979 as the same may have been assigned and amended from
time to time to date (the "LEASE").

                  1.1.6 All right,  title and interest of Seller,  in and to any
easements,  rights-of-way,  interests,  appurtenances  and other  rights of any
kind  relating to or pertaining to the  Land.


                                    ARTICLE 2

                                 PURCHASE PRICE

         2.1      PURCHASE PRICE.   The purchase  price for the Property to be
paid by Purchaser to Seller shall be the amount of ELEVEN  MILLION THREE HUNDRED
SIXTY EIGHT THOUSAND AND 00/100 ($11,368,000.00) DOLLARS (the "PURCHASE PRICE").

         2.2      PAYMENT OF PURCHASE PRICE.  Purchaser agrees to pay the
Purchase Price to Seller as follows:

                  2.2.1 DEPOSIT. ONE MILLION ONE HUNDRED THIRTY-SIX THOUSAND
EIGHT HUNDRED AND 00/100 ($1,136,800.00) DOLLARS (the "DEPOSIT") paid
simultaneously herewith by wire transfer of immediate clearance Federal Reserve
Funds (as such term is hereinafter defined in Section 2.2.2) to, at Seller's
direction, the escrow account of Goldfarb & Fleece or to Chicago Deferred
Exchange Corporation. The proceeds of the Deposit, and all interest accrued
thereon, shall be held in escrow and shall be payable in accordance with Article
23 hereof.

                  2.2.2 PAYMENT AT CLOSING. TEN MILLION TWO HUNDRED THIRTY-ONE
THOUSAND TWO HUNDRED AND 00/100 ($10,231,200.00) DOLLARS (the "CASH BALANCE")
shall be paid by Purchaser to Seller at the Closing. The Cash Balance shall be
paid by wire transfer of immediate clearance " Federal Reserve Funds" (as such
term is hereinafter defined) to such account and bank or other institution as
Seller may, in writing, designate, provided that Seller may designate on not
less than one (1) business day's prior notice that the Cash Balance be wire
transferred to not more than three (3) designated recipients. As used herein,
the term "FEDERAL RESERVE FUNDS" shall be deemed to mean the receipt by a bank
or banks or other institution in the continental United States designated by
Seller of U.S. dollars in form that does not require further clearance, and may
be applied at the direction of Seller by such recipient bank or banks or other
institution on the day of receipt of advice that such funds have been wire
transferred. The description of the manner in which such funds are to be
transmitted, and the number of designated recipients thereof, shall apply with
respect to the Cash Balance as well as to any other funds to be paid to Seller
hereunder, including, but not limited to, any funds to be paid to Seller as a
result of the adjustments to be made pursuant to Article 13 hereof.


                                       2
<PAGE>

                                    ARTICLE 3

                         REPRESENTATIONS AND WARRANTIES

         3.1      REPRESENTATIONS OF SELLER.  Seller hereby represents and
warrants to Purchaser that the following facts and conditions exist on the date
hereof.

                  3.1.1 THE LEASE. The Property is leased to Tenant pursuant to
the Lease, which is in full force and effect.

                  3.1.2 NO FOREIGN PERSON. Seller is not a "foreign  person" as
such term is defined in Section  1445 of the  Internal  Revenue  Code of 1954,
as amended (the "CODE").

         3.2 AUTHORITY AND BINDING EFFECT; NO BREACH OR PROHIBITION. Each party
hereto represents to the other that each person or entity executing this
Agreement by or on behalf of the representing party has the authority to act on
its behalf, has been or will be duly authorized to act on its behalf, and that
the performance of this Agreement will not be in violation of its by-laws,
charter, operating, partnership or trust agreement, or any law, ordinance, rule,
regulation or order of any governmental body having jurisdiction, or the
provisions of any agreements to which it is a party or by the terms of which it
is bound, and, at the Closing, each party shall furnish to the other party and
to the "Title Company" (as such term is defined in Section 5.1 hereof),
reasonably satisfactory evidence of such authority and approval.

         3.3 PURCHASER'S KNOWLEDGE; DISCLOSURE. To the extent that Purchaser
has, subsequent to the date hereof, actual knowledge of any default or any
misrepresentation or incorrect warranty of Seller made in this Agreement,
Purchaser shall promptly notify Seller of same. Reference is made to Section
20.1 hereof with respect to the effect of Purchaser's knowledge of any
misrepresentation or incorrect warranty at or before the Closing.

         3.4 DISCLAIMER OF REPRESENTATIONS AND WARRANTIES. Purchaser
acknowledges that, except as expressly provided herein, neither Seller nor
anyone acting for or on behalf of Seller has made any representation, warranty,
or promise to Purchaser concerning (a) the physical aspects and conditions of
the Property or any portion of the Property, (b) the feasibility or desirability
of the purchase of the Property; (c) the market status, projected income from or
development expenses of the Property; (d) the Property's compliance or
non-compliance with any requirements of laws, or (e) any other matter whatsoever
with respect to the Property (except as contained herein), express or implied,
including, by way of description but not limitation, those of fitness for a
particular purpose, tenantability, habitability and use; and that all matters
concerning the Property are to be independently verified by Purchaser. Purchaser
acknowledges that, except as otherwise expressly provided in this Agreement, it
is purchasing the Property in its physical condition as of the Closing Date.



                                       3
<PAGE>

         3.5      RIGHT TO ADJOURN  CLOSING. Seller shall have the right to
adjourn the Closing for up to sixty (60) days, for the purpose of curing any
default,  misrepresentation or incorrect warranty.


                                    ARTICLE 4

                           STATE OF TITLE OF PROPERTY

         4.1      PERMITTED ENCUMBRANCES.  Purchaser shall accept title to the
Property subject to the following (the "PERMITTED ENCUMBRANCES"):

                  4.1.1 The matters set forth in SCHEDULE B attached hereto and
made a part hereof.

                  4.1.2 In addition to the restrictive covenants referred to in
SCHEDULE B, such other covenants, restrictions,  easements and agreements of
record, if any, affecting the Property, or any part thereof.

                  4.1.3 Any mechanic's lien or other lien which is the
obligation of the Tenant under the Lease to bond or remove of record.

                  4.1.4 Any exception to coverage by the Title Company, other
than a Permitted  Encumbrance,  provided that the Title Company insures same
against collection out of or enforcement against the Property.

                  4.1.5 Any easement or right of use created in favor of any
public utility company for electricity, steam, gas, telephone, water or other
service, and the right to install, use, maintain, repair and replace wires,
cables, terminal boxes, lines, service connections, poles, mains, facilities and
the like, upon, under and across the Property.

                  4.1.6 The printed exceptions contained in the form of title
insurance policy then issued by the Title Company which shall insure Purchaser's
title.

                  4.1.7 Possible lack of right to maintain vaults, fences
retaining walls, chutes, cornices and other installations encroaching beyond the
property line and possible variance between the record description and the tax
map.

                  4.1.8 Any state of facts an accurate survey or personal
inspection of the Property would disclose.

                  4.1.9 Liens,  encumbrances  or any other  matters  created or
suffered by Tenant including, but not limited to, those which are the
obligation  of Tenant to pay, discharge, remove or comply with.


                                       4
<PAGE>

                  4.1.10 Anything or matter arising, directly or indirectly,
out of, under or in connection with the Lease and which is the obligation or
responsibility of Tenant.


                                    ARTICLE 5

                 TITLE INSURANCE AND ABILITY OF SELLER TO CONVEY

         5.1     TITLE INSURANCE. Seller shall give and Purchaser shall accept a
title search as Chicago Title Insurance Company (the "TITLE COMPANY") will be
willing to insure subject only to the matters provided for in this Agreement.
Purchaser agrees to make, promptly after the signing hereof, application for a
title insurance report directly from the Title Company. Purchaser shall deliver
to Seller's attorneys, Goldfarb & Fleece, 345 Park Avenue, New York, New York
10154, Attention: Emanuel Lubin, Esq., not more than twenty (20) days from the
date hereof, a copy of the title report issued by Title Company together with a
written notice by Purchaser of any objections to title which are not Permitted
Encumbrances and which Purchaser is unwilling to waive. In the event Seller is
required or desires to remove any objection, but is unable to do so prior to the
Closing Date, Purchaser hereby grants to Seller a reasonable adjournment of the
Closing Date during which time Seller may attempt to remedy same for a period up
to one hundred twenty (120) days.

         5.2     TITLE OBJECTIONS. (i) If there are any liens, charges,
easements, agreements of record, encumbrances or other objections to title
(collectively, "TITLE OBJECTIONS"), other than (x) the Permitted Encumbrances or
(y) Title Objections which Purchaser has waived or agreed to take title subject
to, which are not waived in accordance with the provisions of Section 5.1 which
were caused by, resulted from or arose out of a grant by Seller to any person or
entity of a mortgage or other security interest affecting the Property, or the
performance of work on behalf of Seller upon all or any portion of the Property,
then Seller shall remove such Title Objections. If Seller fails to remove any
Title Objection(s) in accordance with the provisions of the immediately
preceding sentence, Purchaser, nevertheless, may elect (at or prior to Closing)
to consummate the transaction provided for herein subject to any such Title
Objection(s) as may exist as of the Closing Date, with a credit allocated
against the Cash Balance payable at the Closing equal to the sum necessary to
remove such Title Objection(s), provided, however, if Purchaser makes such
election, Purchaser shall not be entitled to any other credit, nor shall Seller
bear any further liability, with respect to any such Title Objections(s). If
Purchaser shall not so elect, Purchaser may terminate this Agreement and (a)
Seller's sole liability thereafter shall be to cause the Deposit, together with
any interest earned thereon while in escrow, to be refunded to Purchaser, and,
upon the return of the Deposit and any such interest, this Agreement shall be
terminated and the parties hereto shall be relieved of all further obligations
and liability under this Agreement, other than with respect to the provisions of
this Agreement which expressly survive a termination of this Agreement and (b)
such termination shall not otherwise affect the Lease or the Option Agreement
dated July 25, 1979 between Seller as Optioner and 089 Nosidam Corp., as
Optionee, as the same may have been heretofore assigned and amended from time to
time to date (the "OPTION AGREEMENT").



                                       5
<PAGE>


                                    (ii)....If, at the time of the conveyance of
the Property, the Property is affected by or subject to the lien of unpaid
franchise taxes or New York City Corporation Business Taxes of any corporation
or trust in the chain of title, Purchaser shall take title subject thereto,
provided that the Title Company will insure against collection of such taxes out
of the Property without the payment of any additional premium therefor by
Purchaser.

         5.3     NO FURTHER ACTION. Except as expressly set forth in Sections
5.1 and 5.2 hereof, nothing contained in this Agreement shall be deemed to
require Seller to take or bring any action or proceeding or any other steps to
remove any Title Objections, or to expend any moneys therefor, nor shall
Purchaser have any right of action against Seller, at law or in equity, for
Seller's inability to convey title in accordance with the terms of this
Agreement. However, Seller agrees to discharge any lien imposed on the Property
during the time Seller has owned the Property, which may be discharged by a
liquidated ascertainable sum of money and which is not a Permitted Encumbrance.

                                    ARTICLE 6

                                  CLOSING COSTS

         6.1     PURCHASER'S OBLIGATIONS. Purchaser shall pay the costs of
examination of title and any owner's policy of title insurance to be issued
insuring Purchaser's title to the Property, as well as all other title charges,
survey fees, mortgage recording tax, if applicable, and any and all other costs
or expenses incident to the recordation of the Deed (as hereinafter defined).

         6.2     SELLER'S OBLIGATIONS.  Seller shall pay the following amounts
payable in connection with the delivery of the Deed:

                  (i)      the amount imposed pursuant to Article 31 of the New
York State Tax Law; and

                  (ii)     the amount due in connection with the Real Property
Transfer Tax imposed by Title 11 of Chapter 21 of the Administrative Code of the
City of New York.


                                    ARTICLE 7

                              INTENTIONALLY OMITTED

                                    ARTICLE 8

                              INTENTIONALLY OMITTED



                                       6
<PAGE>


                                    ARTICLE 9

               ACKNOWLEDGMENTS OF PURCHASER; CONDITION OF PROPERTY

         9.1     ANALYSIS AND EVALUATION OF THE PROPERTY. Purchaser acknowledges
that Purchaser has made its own analysis and evaluation of the Property, the
operation, the income potential, profits and expenses thereof, its condition and
all other matters affecting or relating to the transaction underlying this
Agreement as Purchaser deemed necessary, including, without limitation, the
layout, the Lease, square footage, rents, income, expenses and operation of the
Property. In entering into this Agreement, Purchaser has not been induced by,
and has not relied upon any, representations, warranties, statements or
covenants, express or implied, made by Seller or any agent, employee or other
representative of Seller which are not expressly set forth in this Agreement.

         9.2     NO EFFECT ON PURCHASER'S OBLIGATIONS. Purchaser further
acknowledges that its covenants, agreements and obligations under this Agreement
shall not be excused or modified by: (i) the business or financial condition of
Tenant, (ii) the physical condition of the Building or personal property, or its
fitness, merchantability or suitability for any use or purpose, (iii) rents,
income or expenses of the Property, (iv) the compliance or non-compliance of the
Property with any laws, codes, ordinances, rules or regulations of any
Governmental Authority and any violations thereof existing or subsequently
imposed, (v) the environmental condition of the Property or the Property's
compliance or non-compliance with any laws, codes, ordinances, rules or
regulations or any Governmental Authority relating to the presence, use,
storage, handling or removal of any hazardous substances, (vi) the current or
future use of the Property, including, but not limited to, the Property's use
for commercial, retail, industrial or other purposes, (vii) the current or
future real estate tax liability, assessment or valuation of the Property,
(viii) the availability or nonavailability or any benefits conferred by Federal,
state or municipal laws, whether for subsidiaries, special real estate treatment
or other benefits of any kind, (ix) the availability or unavailability of any
licenses, permits, approvals or certificates which may be required in connection
with the operation of the Property, (x) the compliance or non-compliance of the
Property, in its current zoning or a variance with respect to the Property's
non-compliance, if any, with any zoning ordinances, except as herein
specifically set forth, or (xi) the conformity of the use of the Property with
any certificate of occupancy.

         9.3     NO OTHER REPRESENTATIONS. Purchaser hereby expressly
acknowledges that, except as expressly provided in Section 3.1, neither Seller
nor anyone acting for or on behalf of Seller has made any representation,
warranty, or promise to Purchaser concerning any of the foregoing, nor: (a) the
physical aspect and condition of any portion of the Property; (b) the
feasibility or desirability of the purchase of the Property; (c) the market
status, projected income from or development expenses for the Property; or (d)
any other matter whatsoever with respect to the Property (except as contained
herein), express or implied, including by way of description, but not
limitation, those of fitness for a particular purpose, tenantability,
habitability and use, and that all matters concerning


                                       7
<PAGE>

the Property have been independently verified by Purchaser. Purchaser
acknowledges and agrees to take the Property "as is", in its physical condition
and state of repair as of the Closing Date.

         9.4     OUTSIDE REPRESENTATIONS. Seller is not liable or bound in any
manner by any verbal or written statements, representations, real estate
"set-ups," offering memorandum or information pertaining to the Property or its
physical condition, layout, the Lease, footage, rents, income, expenses,
operation or any other matter or thing furnished by any agent, employee,
servant, or any other person, unless specifically set forth in this Agreement.
Purchaser hereby waives, to the extent permitted by law, any and all implied
warranties.

         9.5     ENVIRONMENTAL INVESTIGATION OF THE PROPERTY. Purchaser
acknowledges that it has had an opportunity to conduct its own environmental
investigation of the Property. Purchaser is aware of the environmental
conditions affecting or related to the Property and Purchaser agrees to take the
Property subject to such conditions. Purchaser agrees to assume all
environmental costs and liabilities arising out of or in any way connected to
the Property and the condition thereof. Purchaser agrees to indemnify Seller
from any obligation to pay any such costs and liabilities and to indemnify and
hold harmless Seller from and against any and all claims, demands, payments,
losses, costs and expenses, including attorneys' fees, relating to any such
investigation or condition as well as any such costs and liabilities. The
provisions of this Section 9.5 shall survive the Closing.

                                   ARTICLE 10

                           OPERATIONS PRIOR TO CLOSING

         10.1     CONTINUED OPERATION. Purchaser acknowledges that the Property
is leased to Tenant pursuant to the Lease and, accordingly, Tenant, and not
Seller, has control over and operates the Property.


                                   ARTICLE 11

                           CASUALTY AND EMINENT DOMAIN

         11.1 CASUALTY. Restoration of any damage or destruction to the Property
or any part thereof due to fire or other casualty shall not affect the Purchase
Price or the Closing hereunder or any other rights or obligations of the parties
under this Agreement. Provided Closing occurs, Seller agrees to deliver to
Purchaser any proceeds of insurance actually received by Seller in connection
with any such fire or casualty.



                                       8
<PAGE>

         11.2     EMINENT DOMAIN. In the event of condemnation of the Property
or any part thereof between the date hereof and the Closing Date, such
condemnation shall not affect the Purchase Price or the Closing hereunder or any
other rights or obligations of the parties under this Agreement, provided,
however, so long as Closing occurs, Purchaser shall be entitled to any and all
awards then or thereafter made in condemnation proceeding and Seller shall
assign, or in the case of any award previously made, deliver to Purchaser at
Closing, such award as may be made or all rights thereto.

         11.3.    SURVIVAL.   This Article 11 shall  survive the Closing and is
intended to be an express  provision to the  contrary  within the meaning of
Section  5-1311 of the General Obligations Law.


                                   ARTICLE 12

                              INTENTIONALLY OMITTED

                                   ARTICLE 13

                               CLOSING ADJUSTMENTS

         13.1     ADJUSTMENTS AND PRORATIONS.    The following matters and items
shall be apportioned or adjusted between the parties hereto at the closing of
title to the Property pursuant to this Agreement (the "Closing"), as of 12:01.
A.M. on the day of the Closing.

                  13.1.1   BASIC RENT.  Basic Rent paid or payable by Tenant
under the Lease shall be adjusted and prorated.

         13.2.    OTHER.   Except as otherwise provided in this Agreement,
the customs regarding title closings,  as recommended by The Real Estate Board
of New York, Inc., shall apply to all apportionments.


                                   ARTICLE 14

                   CLOSING DOCUMENTS; OBLIGATIONS OF PURCHASER
                              AND SELLER AT CLOSING



                                       9
<PAGE>

         14.1    SELLER'S OBLIGATION TO CLOSE. In the event of a default by
Tenant under the Lease and the termination of the Lease as a result thereof
prior to Closing, this Agreement shall immediately expire upon such termination
of the Lease and, thereupon, the rights and privileges of Purchaser hereunder
shall be null and void and Seller shall have no obligation of any kind or nature
whatsoever to Purchaser hereunder except that, so long as (i) Purchaser is not
otherwise in default of any of its obligations hereunder and (ii) Seller is not
entitled to a refund of the Deposit and any interest thereon pursuant to any
provision of this Agreement, the Deposit and any interest thereon shall be
returned to Purchaser. Upon the return of the Deposit and any such interest, the
parties hereto shall be relieved of all further obligations and liability under
this Agreement other than with respect to provisions of this Agreement which
expressly survive a termination of this Agreement including, but not limited to,
the next succeeding sentence of this Section 14.1. At the request of Seller,
Purchaser will execute and deliver to Seller a written statement, in recordable
form, that this Agreement is null and void.

         14.2     SELLER'S OBLIGATIONS AT CLOSING.   On the Closing Date, Seller
shall deliver or cause to be delivered to Purchaser the following:

                  14.2.1 A bargain and sale deed without covenant conveying
title to the Property (which deed shall not contain the covenant required by
Section 13 of the Lien Law) (the "Deed").

                  14.2.2 A letter to Tenant advising Tenant of the change of
ownership of the Property (the "Tenant  Notice  Letter"), and Purchaser agrees
to deliver the Tenant Notice Letter to Tenant promptly after the Closing.

                  14.2.3 Evidence reasonably acceptable to the Title Company
authorizing the consummation by Seller of the transaction contemplated by this
Agreement, and the execution and delivery of documents on behalf of Seller.

                  14.2.4 The certificate with respect to FIRPTA compliance in
the form of SCHEDULE C annexed hereto.

                  14.2.5 The New York City Department of Finance Real Property
Transfer Tax Return (the "RPT Return") and the New York State Combined Real
Estate Transfer Tax Return and Credit Line Mortgage Certificate
(the "Form TP-584").

                  14.2.6 A release of the Escrow Agent from its duties, if
applicable, and direction to disburse the Deposit, together with interest
thereon, to Seller.

                  14.2.7 Such other documents as may be reasonably and
customarily required by the Title Company to consummate the transaction
contemplated by this Agreement.

         14.3     PURCHASER'S OBLIGATIONS AT CLOSING. Purchaser shall deliver or
cause to be delivered to Seller on the Closing Date the following:


                                       10
<PAGE>

                  14.3.1 The Cash Balance.

                  14.3.2 Duplicate originals of the RPT Return, Form TP-584 and
the Tenant Notice Letter.

                  14.3.3 Evidence reasonably acceptable to Seller and the Title
Company authorizing the consummation by Purchaser of the transaction which is
the subject of this Agreement, and the execution and delivery of documents on
behalf of Purchaser.

                  14.3.4 A release of the Escrow Agent from its duties, if
applicable, and direction to disburse the Deposit, together with interest
thereon to, or as directed by, Seller.

                  14.3.5 Such other documents as may be reasonably and
customarily required by the Title Company to consummate the transaction
contemplated by this Agreement.

                                   ARTICLE 15

                                   VIOLATIONS

         15.1     Without limiting the generality of the provisions of this
Article 15, Purchaser agrees to purchase the Property subject to any and all
notes or notices of violations of law, ordinances, orders or requirements
whatsoever noted in or issued by any federal, state, municipal or other
governmental department, agency or bureau, or any other Governmental Authority
having jurisdiction over the Property (individually, a "Violation",
collectively, "Violations"), or any lien imposed in connection with any of the
foregoing, or any condition or state of repair or disrepair or other matter or
thing, whether or not noted, which, if noted, would result in a Violation being
placed on the Property. Seller shall have no duty to remove or comply with or
repair any condition, matter or thing, whether or not noted, which, if noted,
would result in a Violation being placed on the Property. Seller shall have no
duty to remove or comply with or repair any of the aforementioned Violations,
liens or other conditions, and Purchaser shall accept the Property subject to
all such Violations and liens, the existence of any conditions at the Property
which would give rise to such Violations or liens, if any, and any governmental
claims arising from the existence of such Violations and liens, in each case
without any abatement of or credit against the Purchase Price.

                                   ARTICLE 16

                                    SALES TAX

         16.1     Although it is not anticipated by the parties that any sales
tax shall be due and payable, Purchaser agrees that Purchaser shall pay any
sales tax assessed in connection with the sale of the Property to Purchaser and
save, defend, indemnify and hold Seller harmless from and against


                                       11
<PAGE>

any and all liability for any sales tax which may now or hereafter be imposed
upon Seller or the Property with respect to the sale of any personal property.
The parties hereto agree that no part of the Purchase Price is attributable to
personal property. The provisions of this Section shall survive the Closing.

                                   ARTICLE 17

                       UNPAID TAXES; LIENS OR ENCUMBRANCES

         17.1.    Seller may use any portion of the Cash Balance to satisfy any
liens or encumbrances which exist on the Closing Date which are not Permitted
Encumbrances, provided that Seller delivers to Purchaser at Closing instruments
in recordable form sufficient to satisfy such liens and encumbrances of record,
together with the cost of recording or filing said instruments, or pay such sums
or perform such acts as will enable the Title Company to insure Purchaser that
such lien(s) will not be collected out of the Property, or deposit with
Purchaser's attorneys reasonably sufficient funds to enable Purchaser's
attorneys to obtain and record such instruments.

         17.2.    If Seller requests within a reasonable time prior to the
Closing Date, Purchaser agrees to provide at the Closing separate certified
checks or official cashier's checks, which in the aggregate equal the amount of
the Cash Balance, in order to pay the amounts payable by Seller pursuant to
Section 6.2 hereof.

                                   ARTICLE 18

                                   THE CLOSING

         18.1     THE CLOSING. The sale and purchase of the Property
contemplated by the terms and conditions of this Agreement shall, subject to the
provisions of this Agreement including, but not limited to, Section 14.1 hereof,
be consummated at the Closing.

                  18.1.1  LOCATION AND DATE OF CLOSING.  (a)   The Closing shall
occur on January 31, 2000 (the "Closing Date") and shall take place at the
offices of Seller's attorneys, Goldfarb & Fleece, 345 Park Avenue, New York, New
York at 10:00 A.M., on the Closing Date.

                           (b)   Seller shall have the right to extend the
Closing Date to May 1, 2000 by notice given to Purchaser no later than
January 21, 2000.

                           (c)   Provided Seller shall have extended the
Closing Date pursuant to the provisions of subparagraph (b) hereof, Seller
shall have the further right to again extend the Closing Date to July 31,
2000 by notice given to Purchaser no later than April 21, 2000.

                                       12
<PAGE>

                           (d)   Notwithstanding the provisions of the preceding
subparagraphs (a), (b), (c) and (d) hereof, Seller, shall have the right to
accelerate the Closing Date to any date after the date which shall be thirty
(30) days  following the date of this  Agreement by notice given to Purchaser at
least fifteen (15) days prior to the date fixed in such notice.

                  18.1.2   DELIVERY OF DOCUMENTS.   At the Closing, the closing
documents referred to in Section 14.1 shall be delivered to Purchaser upon
Seller's receipt of the payments provided for in Article 2, and the delivery of
the documents referred to in Section 14.2.

         18.2     BUSINESS DAY.     For purposes of this Agreement, the term
"Business  Day" shall mean all days except Saturdays, Sundays, and all days
observed by the Federal Government or New York State as legal holidays.


                                   ARTICLE 18A

                                     NOTICES

                  18.A.1  Except as otherwise provided in this Agreement, any
and all notices, elections, demands, requests and responses permitted or
required to be given pursuant to this Agreement shall be in writing, signed by
the party giving the same or by its attorneys, and shall be deemed to have been
duly given and effective upon being: (i) personally delivered with receipt for
delivery; or (ii) deposited with a nationally recognized express overnight
delivery service (e.g., Federal Express) for next Business Day delivery with
receipt for delivery; or (iii) deposited in the United States mail, postage
prepaid, certified with return receipt requested, to the other party at the
address of such other party set forth below, or at such other address within the
continental United States as may be designated by a notice of change of address
and given in accordance herewith. The time period in which a response to any
such notice, election, demand or request must be given shall commence on the
date of receipt thereof. Personal delivery to a party or to any officer,
partner, agent or employee of such party at said address shall be deemed given
and received at the time delivered. Rejection or other refusal to accept, or
inability to deliver because of changed address of which no notice has been
received, shall also constitute receipt. Any such notice, election, demand,
request or response shall be addressed to the respective parties as follows:

                  (i)      if to Seller, to

                           The Benenson Capital Company,
                           Lawrence A. Benenson and Raymond E. Benenson
                           708 Third Avenue, 28th Floor
                           New York, New York10017
                           Attention:   Richard Kessler

                           with a copy by like manner to:


                                       13
<PAGE>

                           Goldfarb & Fleece
                           345 Park Avenue
                           New York, New York 10154
                           Attention:   Emanuel Lubin, Esq.

                  (ii)     if to Purchaser, to:
                           York Avenue Development, Inc.
                           1334 York Avenue
                           New York, New York 10021
                           Attention: Ms Karen S. Schuster

                           with a copy by like manner to:
                           Jones, Day, Reavis & Pogue
                           599 Lexington Avenue
                           New York, New York 10022
                           Attention: Susanna S. Fodor, Esq.

         Any notice executed or received by Goldfarb & Fleece, Esqs., Attention:
Emanuel Lubin, Esq., 345 Park Avenue, New York, New York 10154, Attorneys for
Seller, or Jones, Day, Reavis & Pogue, Esqs., Attention: Susanna S. Fodor, Esq.,
Attorneys for Purchaser, shall have the same force and effect as though signed
or received by the principal.

                                   ARTICLE 19

                               DEFAULTS; GUARANTY

                  19.1     PURCHASER'S DEFAULT. If Purchaser is in default after
five (5) days written notice thereof from Seller of any of the terms or
conditions of this Agreement on its part to be kept and performed or fails to
accept title and pay the Cash Balance in accordance with this Agreement, (i) the
Deposit, together with all interest accrued thereon, if any, shall be refunded
to Seller, (ii) Seller may pursue against Purchaser an action or actions for
specific performance and for such other relief, legal or equitable, as Seller
deems appropriate, (iii) Purchaser shall be liable to Seller for any and all
losses, costs, damages and expenses, including attorneys' fees, incurred by
Seller and arising, directly or indirectly, out of, under or in connection with
any such default or failure, and (iv) the Option Agreement shall thereupon be
null and void and of no further force or effect, but such termination shall not
otherwise affect the Lease.

         19.2. GUARANTY.   As a material inducement for Seller to enter into
this Agreement, Purchaser will deliver to Seller, upon the execution hereof, a
guaranty (the "Guaranty") of Sotheby's Holdings, Inc., a Michigan corporation
(the "GUARANTOR") in the form annexed hereto as SCHEDULE D.


                                       14
<PAGE>

         19.3      SELLER'S DEFAULT. Reference is hereby made to Sections 20.1
and 20.2 hereof for Purchaser's exclusive remedies in the event of a breach of
representation or failure to perform any provision set forth in this Agreement
on the part of Seller. If Seller shall default in the performance of its
obligations hereunder, whether or not Purchaser shall have elected to accept
title in accordance with the provisions of Section 5.2 hereof, then Purchaser's
sole remedy shall be either to (i) terminate this Agreement and receive a refund
of the Deposit together with any interest accrued thereon, together with the
cost of title examination charged by the Title Company, without the issuance of
a title insurance policy, or (ii) bring an action for specific performance of
Seller's obligations under this Agreement, provided, however, that if Purchase
shall not have commenced such action within a period of ninety (90) days
following the date scheduled for Closing hereunder, Purchaser shall be deemed to
have waived its right to proceed under this clause (ii) and shall be deemed
instead to have elected the remedy provided for in clause (i) of this sentence.
If Purchaser shall terminate this Agreement under subdivision (i) above, such
termination shall not otherwise affect the Lease or the Option Agreement.

                                   ARTICLE 20

                              CONDITIONS; SURVIVAL

         20.1     CONDITIONS. (a) If Purchaser has actual knowledge, or should
have actual knowledge by inspection of the Property or of the public records at
or before the Closing, that (i) any representation of Seller hereunder is
untrue, as of the date represented, or (ii) Seller has failed to perform,
observe or comply with any covenant, agreement or condition on Seller's part to
be performed hereunder, Purchaser shall notify Seller of such within five (5)
days after discovery by Purchaser. Purchaser's failure to so notify Seller shall
be deemed to constitute Purchaser's waiver of same as a condition to Closing and
otherwise.

                  (b) In the event that (A) any of Seller's representations made
in Section 3.1 are not true as of the date of this Agreement (and for the
purposes hereof, a representation shall be untrue only if factually untrue and
having a material and materially adverse business or legal impact on Purchaser),
and (B) Purchaser has actual knowledge, or should have actual knowledge by
inspection of the Property or of the public records at or before the Closing,
that any of Seller's representations referred to in clause (A) of this sentence
are untrue, then Purchaser's sole remedy shall be either to pursue the
provisions of subdivision (i) or (ii) in Section 19.3 hereof. If Purchaser shall
terminate this Agreement under subdivision (i) such termination shall not
otherwise affect the Lease or the Option Agreement.

         20.2     SURVIVAL. Except as specifically set forth to the contrary in
this Agreement, none of the representations, warranties, covenants, indemnities,
agreements, obligations or commitments made by Seller in this Agreement shall
survive the Closing, the same being merged in the conveyance.


                                       15
<PAGE>

                                   ARTICLE 21

                             SUCCESSORS AND ASSIGNS

         21.1     ASSIGNMENT. Neither this Agreement nor any of the rights of
Purchaser hereunder (nor the benefits of such rights) may be assigned,
transferred or encumbered without Seller's prior written consent, which consent
may be granted or denied in Seller's sole and absolute discretion, and any
purported assignment, transfer or encumbrance without Seller's prior written
consent shall be void. Notwithstanding the foregoing, Purchaser may assign this
Agreement to any Affiliate of Purchaser as such term "Affiliate" is defined in
Paragraph Third of the Option Agreement, provided that a duplicate original of
such Assignment, executed and acknowledged by Purchaser and Assignee, which
shall provide that Assignee shall agree to observe and perform all of the terms
and provisions of this Agreement on the part of Purchaser to be observed and
performed, shall be delivered to Seller, at least ten (10) business days prior
to the Closing Date.

                                   ARTICLE 22

                                     BROKERS

         22.1    PURCHASER'S REPRESENTATION. Purchaser represents and warrants
to Seller that it has not dealt with any broker, finder or consultant in
connection with the transaction which is the subject of this Agreement.
Purchaser further represents and warrants that in the event any claim is made
against Seller for a broker's, finder's or consultant's commission or fee by
anyone as a result of any acts or actions, claimed acts or actions of Purchaser
or its representatives with respect to the within transaction, Purchaser, its
heirs, successors and assigns do hereby agree to indemnify and hold Seller
harmless from any and all loss, liability, cost, damage or expense with respect
to such claims (including, without limitation, reasonable attorneys' fees and
disbursements) without any charge or cost to Seller. This Section shall survive
the Closing or earlier termination of this Agreement.


                                       16
<PAGE>

                                   ARTICLE 23

                                     ESCROW

         23.1.   DESIGNATION OF ESCROW AGENT. The parties hereto have mutually
requested that Goldfarb & Fleece ("G&F"), to act as escrow agent (the "ESCROW
AGENT") for the purpose of holding the Deposit in accordance with the terms of
this Agreement. Purchaser recognizes that G&F represents Seller herein and, if
it acts as Escrow Agent, has agreed to act as Escrow Agent as an accommodation
to both parties hereto. Purchaser further acknowledges and agrees that in the
event of any dispute between the parties to this Agreement, G&F shall be free to
continue its representation of Seller with regard to these matters.

         23.2.   ESCROW OF DEPOSIT. The proceeds of the Deposit shall be held by
the Escrow Agent until the Closing or sooner termination of this Agreement and
Escrow Agent shall pay over the interest or income earned thereon, if any, to
the party entitled to the ESCROW DEPOSIT (as hereinafter defined) and the party
receiving such interest or income shall pay any income taxes due thereon. The
proceeds of the Deposit are sometimes referred to herein as the "ESCROWED
PROCEEDS" and the Escrowed Proceeds, together with any interest or income earned
thereon, if any, are sometimes referred to herein as the "ESCROW DEPOSIT". In
the event the Closing shall occur in accordance with the provisions of this
Agreement, then, Seller and Purchaser shall deliver to Escrow Agent written
instructions directing Escrow Agent to deliver the Escrow Deposit to Seller or
an institution designated by Seller. If for any reason the Closing does not
occur pursuant to the provisions of this Agreement and either party makes a
written demand upon Escrow Agent, for payment of the Escrow Deposit, then Escrow
Agent shall give written notice, in accordance with the provisions of this
Agreement to the other party of such demand. If Escrow Agent does not receive a
written objection from the other party to the proposed payment of the Escrow
Deposit pursuant to the aforesaid demand within ten (10) days after the delivery
of such notice by Escrow Agent, Escrow Agent is hereby authorized to make such
payment in accordance with the aforesaid demand. If Escrow Agent receives
written objection from the other party to the proposed payment of the Escrow
Deposit pursuant to the aforesaid demand within such ten (10) day period or if
for any other reason Escrow Agent in good faith shall elect not to make such
payment, Escrow Agent shall continue to hold the Escrow Deposit until otherwise
directed by written instructions from Seller and Purchaser or a final judgment
or a court of competent jurisdiction. Escrow Agent, however, shall have the
right at any time to deposit the Escrow Deposit with the clerk of any court of
competent jurisdiction in the State of New York, and Escrow Agent shall give
written notice of such deposit to Seller and Purchaser, and upon such deposit
being made, Escrow Agent shall be discharged from all obligations and
responsibilities hereunder. The parties acknowledge that Escrow Agent is acting
solely as a stakeholder at their request and for their convenience, that Escrow
Agent may act upon any writing believed by it in good faith to be genuine and to
be signed and presented by the proper person and the Escrow Agent shall not be
deemed to be the agent of either of the parties, and that Escrow Agent shall not
be liable to either of the parties for any act or omission on its part unless
taken or suffered in bad faith, in willful disregard of this contract or
involving gross negligence. Escrow Agent shall have no duties or
responsibilities except as set


                                       17
<PAGE>

forth herein. Escrow Agent shall not be bound by any modification of the
Agreement unless the same is in writing and signed by Purchaser and Seller and
if Escrow Agent's duties hereunder are affected, unless Escrow Agent shall have
given prior written consent thereto. Seller and Purchaser shall jointly and
severally indemnify and hold Escrow Agent harmless from and against all costs,
claims and expenses, including reasonable attorneys' fees, incurred in
connection with the performance of Escrow Agent's duties hereunder, except with
respect to actions or omissions taken or suffered by Escrow Agent in bad faith,
in willful disregard of this Agreement or involving gross negligence on the part
of Escrow Agent. If the Escrow Deposit shall not earn any interest or income, or
if no interest or income shall be paid thereon by reason of the withdrawal of
proceeds, or part thereof, under the provisions of this Agreement or before
interest shall be earned or credited, or during any period of reasonable delay
in opening the account, Escrow Agent shall not be liable by reason thereof.

                                   ARTICLE 24

                                  MISCELLANEOUS

         24.1    TAX FREE EXCHANGE. Purchaser acknowledges that Seller or one or
more of the parties comprising Seller may structure this transaction as a tax
free exchange under IRC Section 1031 and agrees to execute such documents as
such Seller may reasonably request in connection therewith. This provision shall
survive Closing.

         24.2    MERGER. This Agreement constitutes the entire understanding
between the parties with respect to the transaction contemplated herein, and all
prior or contemporaneous oral agreements, understandings, representations and
statements are merged into this Agreement. Neither this Agreement nor any
provisions hereof may be modified, amended, discharged or terminated except by
an instrument in writing signed by the party against which the enforcement of
such modification, amendment, discharge or termination is sought, and then only
to the extent set forth in such instrument. Unless otherwise provided herein, no
provision of this Agreement may be waived except by an instrument in writing
signed by the party against which the enforcement of such waiver is sought.

         24.3     HEADINGS.   The Article,  Section,  Schedule and Exhibit
headings used herein are for convenience only, and are not to be used in
determining the meaning of this Agreement or any part hereof.

         24.4     GOVERNING LAW.   This Agreement and its interpretation and
enforcement shall be governed by the laws of the State of New York without
regard to conflict of law principles.

         24.5     JURISDICTION. For the purposes of any suit, action or
proceeding involving this Agreement, Seller and Purchaser hereby expressly
submit to the jurisdiction of all federal and state courts sitting in the State
of New York, and consent that any order, process, notice of motion or


                                       18
<PAGE>

other application to or by any such court, or a judge thereof, may be served
within or without such court's jurisdiction by registered mail or by personal
service, provided that a reasonable time for appearance is allowed, and Seller
and Purchaser agree that such courts shall have the exclusive jurisdiction over
any such suit, action or proceeding commenced by either or both of said parties.
In furtherance of such agreement, Seller and Purchaser agree upon the request of
the other party to discontinue (or agree to the discontinuance of) any such
suit, action or proceeding pending in any other jurisdiction.

         24.6     WAIVER OF VENUE AND INCONVENIENT FORUM CLAIMS. Seller and
Purchaser hereby irrevocably waive any objection that it may now or hereafter
have to the laying of venue of any suit, action or proceeding arising out of or
relating to this Agreement brought in any federal or state court sitting in the
State of New York, and hereby further irrevocably waive any claim that any such
suit, action or proceeding is brought in any inconvenient forum.

         24.7     WAIVER OF JURY TRIAL. Each of the parties hereto waives,
irrevocably and unconditionally, any and all right to trial by jury in any
action brought on, under, or by virtue of, or relating in any way to this
Agreement or the transactions contemplated hereby, or any of the documents
executed in connection herewith, the Property, or any claims, defenses, rights
of set-off or other actions pertaining hereto or to any of the foregoing.

         24.8     SUCCESSORS AND ASSIGNS.   This Agreement shall be binding on
and inure to the benefit of the successors and permitted assigns of the parties
hereto.

         24.9     INVALID PROVISIONS. If any term or provision of this
Agreement, or any part of any term or provision, or the application thereof to
any person or circumstance shall to any extent be held invalid or unenforceable,
the remainder of this Agreement or the application of such term or provision or
remainder thereof to persons or circumstances other than those as to which it is
held invalid and unenforceable shall not be affected thereby, and each term and
provision of this Agreement shall be valid and enforceable to the fullest extent
permitted by law.

         24.10    SCHEDULES AND EXHIBITS.  All Schedules and Exhibits which are
annexed to this Agreement are a part of this Agreement and are incorporated
herein by reference.

         24.11    NO OTHER PARTIES. The provisions of this Agreement are for the
sole benefit of the parties to this Agreement and their successors and permitted
assigns, and shall not give rise to any rights by or on behalf of anyone other
than such parties, and no party is intended to be a third party beneficiary
hereof. No provisions of this Agreement, or of any of the documents and
instruments executed in connection herewith, shall be construed as creating in
any person or entity other than Purchaser and Seller and their permitted assigns
any rights of any nature whatsoever.

         24.12    INTERPRETATION. This Agreement shall be construed without
regard to any presumption or other rule requiring construction against the party
causing this Agreement to be drafted.


                                       19
<PAGE>

         24.13    COUNTERPARTS; FAXED SIGNATURES. This Agreement may be executed
in multiple counterparts, each of which shall, when executed, be deemed to be an
original, and all of which when taken together shall constitute but one
agreement. Each party may rely upon a faxed counterpart of this Agreement
executed and delivered by the other party as if such counterpart were an
original counterpart.

         24.14    BINDING EFFECT. This Agreement shall not become a binding
obligation upon Seller until the same has been fully executed by Purchaser and
Seller, and until a fully executed original counterpart thereof has been
delivered by Seller to Purchaser.

         24.15    RECORDATION.  Neither this Agreement, nor any other document
related hereto, nor any memorandum thereof shall be recorded, and any such
recording shall be void and of no force or effect.

         24.16    LITIGATION FEES. In the event that any litigation arises under
this Agreement, the prevailing party (which term shall mean the party which
obtains substantially all of the relief sought by such party) shall be entitled
to recover, as part of its judgment, reasonable attorneys' fees.

         24.17    SINGULAR/PLURAL.  The use of the singular shall be deemed to
include the plural, and vice versa, whenever the context so requires.

         24.18    SIGNATORIES OF SELLER. The individual executing this Agreement
as a Trustee is acting solely in his capacity as trustee, and not in his
individual capacity, and shall incur no personal liability on account of such
execution.


                                       20
<PAGE>

                  IN WITNESS WHEREOF, the parties hereto have executed this
Agreement of Sale and Purchase as of the date first above written.

                           THE BENENSON CAPITAL COMPANY, a New York
                           general partnership

                           By:  The Charles B. Benenson Family Trust, a partner

                                By:  /s/ Charles B. Benenson
                                    -------------------------------------------
                                             Charles B. Benenson, Trustee

                                     /s/ Lawrence A. Benenson
                                    -------------------------------------------
                                             Lawrence A. Benenson

                                     /s/ Raymond E. Benenson
                                    -------------------------------------------
                                             Raymond E. Benenson
                                                                , as Seller

                           YORK AVENUE DEVELOPMENT, INC.

                           By: /s/ William F. Ruprecht
                               ------------------------------------------------
                               WILLIAM F. RUPRECHT, as Purchaser

The undersigned, Escrow Agent, agrees to hold the proceeds of the Deposit in
accordance with the provisions of Section 23.2.

Goldfarb & Fleece

By: /s/ Emmanuel Lubin
    -------------------------------------------
    EMMANUEL LUBIN
                                       21
<PAGE>

                                   SCHEDULE A

ALL that certain plot, piece or parcel of land, situate, lying and being in the
Borough of Manhattan, City, County and State of New York, bounded and described
as follows:

BEGINNING at the corner formed by the intersection of the easterly side of York
Avenue (formerly Avenue A) and the southerly side of 72nd Street; running thence
in a southerly direction along the easterly side of York Avenue 204 feet 4
inches to the corner formed by the intersection of the easterly side of York
Avenue and the northerly side of 71st Street; running thence in an easterly
direction along the northern side of 71st Street, 198 feet; thence in a
northerly direction and parallel with York Avenue 204 feet 4 inches to the
southerly side of 71st Street; and thence in a westerly direction along the
southerly side of 72nd Street 198 feet to the point or place of BEGINNING.


                                       22
<PAGE>

                                   SCHEDULE B

     1.   Consent by any former owner of the Property for the erection of any
structure or structures on, under or above any street or streets on which the
Property may abut.

     2.   Present and future zoning laws, ordinances, resolutions and
regulations of the City of New York and all present and future ordinances, laws,
regulations, requirements and orders of all departments, boards, bureaus,
commissions, bodies and authorities of the federal, state or municipal
governments now or hereafter having or acquiring jurisdiction of the Property
and the use and improvement thereof.

     3.   Revocable nature of the right, if any, to maintain vaults, vault
spaces, basement and subbasement spaces, areas, marquees or signs, beyond the
building lines.

     4.   Violations of laws, ordinances, orders or requirements that might be
disclosed by an examination and inspection or search of the Property by any
federal, state or municipal department or authority having jurisdiction, as the
same may exist on the Closing Date.

     5.   The condition and state of repair of the Property as the same may be
on the Closing.

     6.   Restrictive covenants recorded in Liber 1199 of Conveyances, page 151.

     7.   The Lease as referenced in Memorandum of Lease dated as of July 25,
1979, recorded in Reel 490, Page 1477.

     8.   Any liens or encumbrances affecting Lessee's interest in the Lease.

     9.   Unpaid real estate taxes, assessments, water rates, sewer rents and
charges, and governmental impositions, duties and charges of every kind or
nature whatsoever, levied, assessed or imposed or a lien upon the Property.

     10.  Rights of subtenants and occupants under the Lease.

     11.  Section 4.1 of the Agreement of which this Schedule is a part.

     12.  The Option Agreement as referenced in Memorandum thereof recorded in
Reel 556 Page 868.

     13.  Exchange Agreement between Seller and 089 Nosidam Corp. as the same
may have been amended to date.

     14.  Exchange Agreements, between Seller and Purchaser and a Memorandum
thereof recorded in Reel 1180, Page 1573 as the same may have been amended to
date.


<PAGE>

                                   SCHEDULE C

                        CERTIFICATE OF NON-FOREIGN STATUS

                  To inform _____________  _______________  ____________  ______
___________  __________________________________________________________________
("Transferee"), that withholding of tax under Section 1445 of the Internal
Revenue Code of 1954, as amended ("Code") will not be required by, THE BENENSON
CAPITAL COMPANY, a New York general partnership ("Transferor"), the undersigned
hereby certifies the following on behalf of Transferor:

     1.   Transferor is not a foreign corporation, foreign partnership, foreign
trust, estate or foreign person (as those terms are defined in the Code and the
Income Tax Regulations promulgated thereunder);

     2.   Transferor's U.S. employer identification number is 13-6593262.

         Transferor understands that this certification may be disclosed to the
Internal Revenue Service by Transferee and that any false statement contained
herein could be punished by fine, imprisonment, or both.

         Under penalty of perjury I declare that I have examined this
Certification and to the best of my knowledge and belief, it is true, correct
and complete, and I further declare that I have authority to sign this document
on behalf of Transferor.

                     THE BENENSON CAPITAL COMPANY,

                     a New York general partnership

                     By:      The Charles B. Benenson Family Trust, a partner

                              By:______________________________________
                                       Charles B. Benenson, Trustee

__________, 2000

                                                   SCHEDULE C-1


<PAGE>



                        CERTIFICATE OF NON-FOREIGN STATUS

                  To inform ___________________________________________________
______________________________________________________________________________
("Transferee"), that withholding of tax under Section 1445 of the Internal
Revenue Code of 1954, as amended ("Code") will not be required by LAWRENCE A.
BENENSON ("Transferor"), the undersigned hereby certifies the following on
behalf of Transferor:

          1.   Transferor is not a foreign corporation, foreign partnership,
foreign trust, estate or foreign person (as those terms are defined in the Code
and the Income Tax Regulations promulgated thereunder);

          2.   Transferor's U.S. social security number is ###-##-####.

         Transferor understands that this certification may be disclosed to the
Internal Revenue Service by Transferee and that any false statement contained
herein could be punished by fine, imprisonment, or both.

         Under penalty of perjury I declare that I have examined this
Certification and to the best of my knowledge and belief, it is true, correct
and complete, and I further declare that I have authority to sign this document
on behalf of Transferor.

                          ------------------------------------
                                 Lawrence A. Benenson

__________, 2000

                                  SCHEDULE C-2


<PAGE>

                        CERTIFICATE OF NON-FOREIGN STATUS

                  To inform ___________________________________________________
________________________________________________________________________________
("Transferee"), that withholding of tax under Section 1445 of the Internal
Revenue Code of 1954, as amended ("Code") will not be required by RAYMOND E.
BENENSON("Transferor"), the undersigned hereby certifies the following on behalf
of Transferor:

          1.   Transferor is not a foreign corporation, foreign partnership,
foreign trust, estate or foreign person (as those terms are defined in the Code
and the Income Tax Regulations promulgated thereunder);

          2.   Transferor's U.S. social security number is ###-##-####.

         Transferor understands that this certification may be disclosed to the
Internal Revenue Service by Transferee and that any false statement contained
herein could be punished by fine, imprisonment, or both.

         Under penalty of perjury I declare that I have examined this
Certification and to the best of my knowledge and belief, it is true, correct
and complete, and I further declare that I have authority to sign this document
on behalf of Transferor.

                          ------------------------------------
                                  Raymond E. Benenson

__________, 2000

                                                   SCHEDULE C-3


<PAGE>

                                   SCHEDULE D

                                    GUARANTY

               KNOW ALL MEN BY THESE PRESENTS THAT

               WHEREAS:

               1.   The Benenson Capital Company, a New York general
partnership, Lawrence A. Benenson and Raymond E. Benenson, (referred to
collectively herein as "SELLER") having an office at 708 Third Avenue, New York,
New York 10017, concurrently with the delivery of this instrument has entered
into an Agreement of Sale and Purchase of even date herewith, with York Avenue
Development, Inc. (referred to herein as "PURCHASER"), a New York corporation,
having an office at 1334 York Avenue, New York, New York 10021, affecting
premises known as and by the street number 1334 York Avenue in the Borough of
Manhattan, City, County and State of New York, which aforesaid agreement is
hereby incorporated in this instrument by reference (the aforesaid agreement is
referred to herein as the "AGREEMENT" and the premises demised therein is
referred to herein as the "PREMISES"); and

               2.   The undersigned, Sotheby's Holdings, Inc., a Michigan
corporation (referred to herein as "GUARANTOR"), having an office at 1334 York
Avenue, New York, New York 10021, is the indirect owner of all of the issued
and outstanding stock of Purchaser; and

               3.   Guarantor acknowledges that Seller would not enter into the
Agreement unless this Guaranty accompanied the execution and delivery of the
Agreement.

               NOW, THEREFORE, in consideration of the execution and delivery
of the Agreement by Seller and Purchaser, and of other good and valuable
consideration, the receipt and sufficiency whereof is hereby acknowledged by
Guarantor;


<PAGE>

          FIRST: The undersigned Guarantor does hereby:

11                Covenant and agree with Seller that if Purchaser, its
          successors or assigns, shall default at any time in the payment of the
          Purchase Price or any part thereof or any other payments provided to
          be paid by Purchaser in the Agreement (collectively, the "Amounts"),
          or in the observance or performance of any of the terms, covenants or
          conditions of the Agreement on Purchaser's part to be observed or
          performed, and such defaults shall not be cured before the expiration
          of any applicable grace period, then Guarantor will, on not less than
          ten (10) days prior written notice, well and truly observe and perform
          said terms, covenants and conditions and pay to Seller the Amounts and
          any other charges payable by Purchaser under the Agreement, or any
          arrears thereof that may remain due to Seller, and all damages,
          including, but not limited to, any damages payable pursuant to the
          Agreement that may arise in consequence of Purchaser's insolvency or
          such default in the observance or performance of any of said terms,
          covenants or conditions; and

12                Covenant and agree with Seller that Guarantor may, at Seller's
          option, be joined in any action or proceeding commenced by Seller
          against Purchaser in connection with or based upon the Agreement or
          any term, covenant or condition thereof, and that recovery may be had
          against Guarantor in such action or proceeding or in any independent
          action or proceeding against Guarantor without Seller, or its assigns,
          first asserting, prosecuting or exhausting any remedy or claim against
          Purchaser, its successors or assigns; and

13                Covenant  and agree with  Seller that this  Guaranty  shall
          remain and continue in full force and effect notwithstanding any
          modifications or amendments of the Agreement; and

14                Covenant to indemnify and save Seller harmless of and from all
          cost, liability, damage and expense including, but not limited to,
          reasonable counsel fees, which may arise by reason of Purchaser's
          default under the Agreement and not cured before the expiration of any
          applicable grace period, or Purchaser's insolvency, or Guarantor's
          default hereunder; and

15                Covenant and agree with Seller that this Guaranty shall not be
          terminated, affected or impaired by reason of any action which Seller
          may take or fail to take against Purchaser or by reason of any waiver
          of, or failure to enforce, any of the rights or remedies reserved to
          Seller in the Agreement, or otherwise, provided, however, that
          Guarantor shall be entitled to the same defenses that may legally be
          asserted by Purchaser; and


                                       2
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16                Waive notice of the  acceptance  of this  Guaranty and of any
          and all defaults by Purchaser in the payment of the Amounts, and of
          any and all defaults by Purchaser in the observance or performance of
          any of the terms, covenants or conditions of the Agreement on
          Purchaser's part to be observed or performed, and of any and all
          notices or demands which may be given by Seller to Purchaser, whether
          or not required to be given to Purchaser under the terms of the
          Agreement; and

17                Acknowledge  that this Guaranty is a guarantee of payment and
          not of collection in respect to any obligations which may accrue to
          Seller from Purchaser under the provisions of the Agreement; and

18                Covenant to and agree with Seller that the validity  hereunder
          shall in no way be terminated, affected or otherwise impaired by
          reason of any assignment or transfer of Purchaser's interest in the
          Agreement; and

19                Covenant to and agree with Seller that no failure to exercise
          and no delay in exercising, on the part of Seller, of any right, power
          or privilege under this Guaranty or at law shall operate as a waiver
          thereof, nor shall any single or partial exercise of any right, power
          or privilege preclude any other or further exercise thereof, or the
          exercise of any other power or right. The rights and remedies provided
          in this Guaranty are cumulative and not exclusive of any rights or
          remedies provided by law.


          SECOND: The provisions of this Guaranty shall be binding upon said
Guarantor, its successors and assigns and shall inure to the benefit of Seller,
its successors and assigns, and shall not be deemed waived or modified unless
specifically set forth in writing, executed by Seller and delivered to
Guarantor.

          THIRD: Guarantor agrees that any bills, statements, notices, demands,
requests or other communications given or required to be given to Guarantor
under this Guaranty at Seller's election, shall be addressed to Guarantor at the
above address, by certified mail, return receipt optional.

          FOURTH: The officer executing this Guaranty on behalf of the
undersigned Guarantor represents to Seller that said officer has been duly
authorized by the undersigned


                                       3
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Guarantor to execute and deliver this Guaranty on behalf of the undersigned
Guarantor and that execution and delivery of this Guaranty is a proper and
authorized act of the undersigned Guarantor and does not violate the Articles of
Incorporation or the By-Laws of the undersigned Guarantor or the Laws of the
State of New York.

         IN WITNESS WHEREOF, the undersigned Guarantor has signed and sealed
this Guaranty this day of September, 1999.

                                    Sotheby's Holdings, Inc.


                                    By: ------------------------


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                          CERTIFICATE OF ACKNOWLEDGMENT

STATE OF NEW YORK  )

                   : ss.:

COUNTY OF NEW YORK )

                  On the _____ day of _______________, in the year ___ before
me, the undersigned, a Notary Public in and said State, personally appeared
____________________________________, personally known to me or proved to me on
the basis of satisfactory evidence to be the individual(s) whose name(s) is
(are) subscribed to the within instrument and acknowledged to me that
he/she/they executed the same in his/her/their capacity (ies), and that by
his/her/their signature (s) on the instrument, the individual(s), or the person
upon behalf of which the individual(s) acted, executed the instrument.

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



<PAGE>

                  RE: PROPERTY: 1334 YORK AVENUE, NEW YORK CITY

                  Sotheby's, Inc., Lessee ("Lessee") under the Lease ("Lease")
described in Section 1.1.5 of the Agreement of Sale and Purchase dated
__________, 1999 between THE BENENSON CAPITAL COMPANY, LAWRENCE A. BENENSON and
RAYMOND E. BENENSON, as Seller, and YORK AVENUE DEVELOPMENT, INC., as Purchaser,
does hereby waive Lessee's First Refusal Option on Sale contained in Section 57
of the Lease with reference to the sale and conveyance to Lessee of the fee of
the property covered by said Lease.

Dated:   September __, 1999

                                   SOTHEBY'S, INC.

                                   By: /s/ William F. Ruprecht
                                       -----------------------------------------
                                       WILLIAM F. RUPRECHT