<PAGE>

                                  EXHIBIT 10.21

                                  -------------

                                    GUARANTY

     THIS  GUARANTY  (this  "Guaranty")  is made as of the 20th day of December,
1999, by and from SHELDON G. ADELSON ("Guarantor"), having an address at c/o The
Venetian,  3355 Las Vegas Boulevard  South,  Las Vegas, NV 89109, to and for (i)
The Bank of Nova Scotia,  a Canadian  chartered bank, as Collateral  Agent under
that certain Loan Agreement  dated of even date herewith among (A) Goldman Sachs
Mortgage Company,  and the other lenders from time to time parties thereto,  (B)
Goldman Sachs  Mortgage  Company,  as  Syndication  Agent,  (C) The Bank of Nova
Scotia, a Canadian chartered bank, as Administrative Agent, (D) The Bank of Nova
Scotia, a Canadian  chartered bank,  Collateral Agent, and (E) Grand Canal Shops
Mall Subsidiary,  LLC, a Delaware  limited  liability  company,  as borrower (as
amended,  supplemented  or  otherwise  modified  from  time to time,  the  "Loan
Agreement";  capitalized  terms used  herein and not defined  herein  having the
meanings ascribed to them in the Loan Agreement), having an address noted in the
Loan  Agreement,  (ii) Goldman Sachs Mortgage  Company and the other Lenders and
(iii) the  respective  successors  and assigns of the  Collateral  Agent and the
Lenders (all of the Persons  described in the foregoing  clauses (i) through and
including (iii), the "Beneficiaries"; each such Person, a "Beneficiary").

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

     WHEREAS,  Grand  Canal  Shops  Mall  Subsidiary,  LLC.,  a  Nevada  limited
liability  company  (the  "Borrower")  desires to have the  Lenders  make to the
Borrower,  pursuant  to and  subject to the  terms,  covenants,  agreements  and
conditions of the Loan Agreement, a loan in the principal amount of $105,000,000
(or such lesser amount as Lender shall fund pursuant to that certain  commitment
letter dated as of November 14, 1997 among Borrower, Principal and Goldman Sachs
Mortgage Company) (the "Loan");

     WHEREAS,  the Lenders  are  unwilling  to make the Loan to the  Borrower as
aforesaid  unless,  among other  things,  Guarantor  executes and delivers  this
Guaranty;

     WHEREAS,  (i) the Guarantor owns all of the issued and  outstanding  voting
stock of (A) Las  Vegas  Sands,  Inc.,  a Nevada  corporation  ("LVSI")  and (B)
Interface Group Holding Company, Inc., a Nevada corporation  ("Interface Holding
Co."),  (ii) LVSI owns a managing member interest in, and Interface  Holding Co.
holds all non-managing  membership  interests in, Venetian Casino Resort, LLC, a
Nevada limited  liability company  ("Venetian"),  (iii) Venetian owns all of the
membership  interests  in Mall  Intermediate  Holding  Company,  LLC, a Delaware
limited liability company ("Mall Intermediate Holdings"), (iv) Mall Intermediate
Holdings owns all of the membership  interests in Grand Canal Shops Mall Holding
Company,  LLC, a Delaware limited liability company ("Mall Holdings"),  (v) Mall
Holdings  owns all of the  membership  interests in Grand Canal Shops Mall,  LLC
("Mall LLC") and (vi) Mall LLC owns all of the membership interests in Borrower;

     WHEREAS,  (i) LVSI owns all of the issued and  outstanding  voting stock of
Grand Canal Shops MM, Inc., a Nevada corporation ("MM Inc."),  (ii) MM Inc. owns
all of the issued and  outstanding  voting  stock of Grand  Canal  Shops Mall MM
Subsidiary Inc., a Nevada corporation  ("Managing Member") and (iii) immediately
after the funding of the Loan, (A) Mall Holdings shall assign a one percent (1%)
membership  interest in Mall Holdings to MM Inc.  (such that MM Inc. is the sole
managing member of Mall  Holdings);  and (B) Mall LLC shall assign a one percent
(1%)  managing  membership  interest in Borrower to Managing  Member  (such that
Managing Member is the sole managing member of Borrower);

     WHEREAS,  Guarantor will benefit, directly and indirectly,  from the making
by the Lenders to the Borrower of the Loan as aforesaid;

     NOW,  THEREFORE,  in  consideration of agreement by the Lenders to make the
Loan to the Borrower pursuant to and subject to the terms, covenants, agreements
and  conditions  of  the  Loan   Agreement,   and  the  covenants,   agreements,
representations  and warranties set forth in this Agreement,  the parties hereby
covenant, agree, represent and warrant as follows:

<PAGE>

1.   Guaranty of Payment.

(a)  Guarantor hereby unconditionally, absolutely and irrevocably guarantees, as
     a primary obligor and not merely as a surety, to the Beneficiaries:

     (i)  The prompt and  complete  indefeasible  payment in full,  when due and
          otherwise in accordance  with the terms,  provisions and conditions of
          the Notes and the Loan  Agreement  (but subject to the  provisions  of
          Section 1(b) hereof),  of all principal of the Loan (including amounts
          that would be due under the Loan  Documents,  pursuant  to  applicable
          state law, but for the operation of the  automatic  stay under Section
          362(a) of Title 11 of the United States Code (the "Bankruptcy Code"));
          and

     (ii) The prompt and complete  indefeasible payment in full of all costs and
          expenses of any enforcement,  collection or other  realization  under,
          this Guaranty,  including,  without limitation,  reasonable attorneys'
          fees,  disbursements and other expenses  (collectively,  "Costs";  the
          principal  of the Loan,  together  with all  Costs,  are  collectively
          referred to as the "Obligations").

(b)  Notwithstanding   the  aggregate  amount  of  the  Obligations  and/or  the
     Indebtedness  that at any  time or from  time  to time  may be  payable  by
     Borrower,  the aggregate liability of Guarantor to Beneficiaries under this
     Guaranty  shall  not  exceed  the sum of (x)  the  Twenty  Million  Dollars
     ($20,000,000)  plus (y) all Costs (the portion of the principal of the Loan
     that,  at any given  time,  shall be  payable by the  Guarantor  under this
     Guaranty,  together  with all Costs,  are  collectively  referred to as the
     "Guaranteed Obligations"). Guarantor agrees that the Obligations and/or the

      ----------------------
     Indebtedness may at any time and from time to time exceed the amount of the
     liability  of  Guarantor  hereunder  without  impairing  this  Guaranty  or
     affecting the rights and remedies of any Beneficiary  hereunder.  Guarantor
     agrees  that  whenever  at any time or from time to time it shall  make any
     payment on account of Guarantor's  liability hereunder,  it will notify the
     Collateral  Agent in writing that such payment is made under this  Guaranty
     for such  purpose.  No payment or  payments  made by  Borrower or any other
     Person or received or collected by any Agent or Lender from Borrower or any
     other  Person by  virtue of any  action or  proceeding  or any  set-off  or
     appropriation  or application at any time or from time to time in reduction
     of or in payment  of the  Indebtedness  shall be deemed to modify,  reduce,
     release or otherwise affect the liability of Guarantor hereunder who shall,
     notwithstanding  any  such  payment  or  payments,  remain  liable  for the
     Guaranteed  Obligations  until the date upon which the Obligations are paid
     in full.  Guarantor  shall not be entitled  to make any payment  under this
     Guaranty prior to demand therefor by any Beneficiary.

2.   Representations, Warranties and Covenants.
     -----------------------------------------

(a)  Guarantor represents, warrants and covenants that:

     (i)  No  consents  or  approvals  of any  kind  by  others,  including  any
          creditors  of  Guarantor,   and  no  license,   permit,   approval  or
          authorization  of, exemption by, notice or report to, or registration,
          filing or declaration with, any governmental  authority is required by
          Guarantor,   in  connection  with  this  Guaranty  or  the  execution,
          delivery, performance, validity or enforceability of this Guaranty and
          all  obligations  required  hereunder,  and  this  Guaranty  is not in
          violation  of the  terms  of any  agreement  or  instrument  to  which
          Guarantor  or Borrower is a party or by which either of them or either
          of their respective assets may be bound or affected, and this Guaranty
          will not violate any  provision of any existing law or  regulation  of
          material  import,  that would result in a material  adverse  effect on
          Guarantor,  which is binding  on  Guarantor,  or any order,  judgment,
          award or decree of any court,  arbitrator  or  governmental  authority
          binding on Guarantor;

     (ii) There  is no  pending  or,  to  the  best  of  Guarantor's  knowledge,
          threatened, action or proceeding affecting Guarantor before any court,
          governmental agency or arbitrator that could reasonably be expected to
          have a material  adverse effect on the ability of Guarantor to perform
          or observe any of its obligations  hereunder or that could  reasonably
          be expected to have a material adverse effect on Guarantor's  guaranty
          of the Guaranteed Obligations hereunder;

     (iii)Guarantor  has full power,  authority  and legal right to execute this
          Guaranty and to observe and perform all of the terms of this  Guaranty
          on  Guarantor's  part to be observed and  performed  and this Guaranty
          constitutes the valid and binding obligation of Guarantor, enforceable
          in  accordance  with its  terms,  except  as such  enforcement  may be
          limited  by  bankruptcy  laws and other laws  affecting  the rights of
          creditors  generally,  or by  virtue  of the  application  of  general
          principles of equity;

<PAGE>

     (iv) This Guaranty is made by Guarantor at the request of Borrower, and the
          Beneficiaries'  agreement to enter into the transactions  described in
          the recitals to this Guaranty is of  substantial,  material and direct
          benefit to Guarantor;

     (v)  Guarantor  has  established  means  with  which  it  is  satisfied  of
          obtaining  from  Borrower on a continuing  basis  financial  and other
          information pertaining to the financial condition of Borrower, and its
          ability to promptly pay the Guaranteed Obligations;

     (vi) Guarantor has reviewed and approved copies of the Loan Documents,  and
          is  fully  informed  of the  rights  and  remedies  that  each  of the
          Beneficiaries may pursue, with or without notice to Borrower.

3.   Access to  Information.  Guarantor  shall,  at its sole  cost and  expense,
     establish and maintain  means whereby  Guarantor  shall be kept informed to
     its satisfaction of any facts,  events or  circumstances  that might in any
     way affect Guarantor's risks hereunder, and the Beneficiaries shall have no
     obligation to disclose to Guarantor information or material acquired in the
     course of any Beneficiary's relationship with Borrower.

4.   Payment by Guarantor;  Application of Payments. Guarantor hereby agrees, in
     furtherance  of the foregoing and not in limitation of any other right that
     any Beneficiary may have at law or in equity against  Guarantor,  that upon
     the Collateral Agent's exercise,  at any time and from time to time, of any
     rights  hereunder  or any demand  pursuant to the terms hereof for payment,
     Guarantor  will upon such demand pay, or cause to be paid,  in cash, to the
     Collateral  Agent,  for the benefit of the Lenders,  an amount equal to the
     Guaranteed  Obligations  then owed under this  Guaranty.  All such payments
     shall be applied promptly from time to time in the following order:

                    First, to the payment of Costs; and
                    -----
                    Second,  to the payment of all other Guaranteed  Obligations
                    ------
               then owed under this Guaranty.

5.   Release  of  Guaranty.  When the  Obligations  are paid in full,  then this
     ---------------------
     Guaranty  shall  automatically  terminate and become void and of no further
     force  or  effect;  at such  time,  at  Guarantor's  written  request,  the
     Beneficiaries  shall execute and deliver a written  statement  stating that
     the  Obligations  have been paid in full and that  this  Guaranty  has been
     terminated and is of no further force and effect.

6.   Liability of Guarantor Absolute.
     -------------------------------

(a)  Guarantor  agrees that its  obligations  hereunder shall not be affected by
     any  circumstance  that  constitutes  a legal or  equitable  discharge of a
     guarantor or surety  (other than payment in full of the  Obligations),  and
     Guarantor's  obligations hereunder are irrevocable,  absolute,  independent
     and unconditional without regard to:

     (i)  any claim or defense that would be available to the Borrower;

     (ii) the imposition of any court-imposed  stay,  including any amounts that
          would be payable but for the  imposition of the  automatic  stay under
          Section 362(a) of the Bankruptcy Code;

     (iii)any readjustments,  modifications, impositions, or extensions that may
          be imposed by any court in connection with any bankruptcy, insolvency,
          receivership,  liquidation,  arrangement,  reorganization  or  similar
          action, case or proceeding affecting Guarantor or the Borrower (any of
          the  foregoing,  a  "Bankruptcy   Proceeding")  that  may  affect  the
          Obligations and/or the Indebtedness or any of the Loan Documents;

     (iv) any law that restricts or prohibits the payment of interest, principal
          or any other amount after the commencement of a Bankruptcy Proceeding;
          or

     (v)  any sale or  disposition  of any  security  given for the  Obligations
          and/or the Indebtedness.

<PAGE>

(b)  In  furtherance of the  provisions of subsection  6(a) hereof,  and without
     limiting the generality thereof, Guarantor agrees that:

     (i)  This Guaranty is a guaranty of payment and not of collection.

     (ii) Any   Beneficiary  may  enforce  this  Guaranty  upon  the  terms  and
          conditions herein set forth notwithstanding any exercise or failure to
          exercise any right or remedy available to such Beneficiary against any
          Person under any documents, at law, in equity or otherwise.

     (iii)The  obligations  of  Guarantor   hereunder  are  independent  of  the
          obligations  of  Guarantor,  Borrower,  any members,  partners,  joint
          venturers,    officers,   directors,    shareholders,    trustees   or
          beneficiaries  (as  applicable)  of Borrower or any other Person under
          the  Loan  Documents   (other  than  this  Guaranty),   including  the
          obligations of any other  guarantor,  and a separate action or actions
          may be brought and  prosecuted  against  Guarantor  whether or not any
          action is brought  against  Guarantor,  Borrower or any other  Persons
          under the Loan Documents (other than this Guaranty) and whether or not
          Borrower or any other Person is joined in any such action or actions.

     (iv) Payment by  Guarantor  of a portion,  but not all,  of the  Guaranteed
          Obligations  shall  in  no  way  limit,  affect,   modify  or  abridge
          Guarantor's  liability for any portion of the  Guaranteed  Obligations
          that has not been paid to the Beneficiaries.

     (v)  The  Beneficiaries  and the  Borrower,  upon  such  terms as they deem
          appropriate,  without  notice  or demand  and  without  affecting  the
          validity  or  enforceability  of this  Guaranty  or giving rise to any
          reduction,   limitation,   impairment,  discharge  or  termination  of
          Guarantor's  liability  hereunder,  from  time to time may (i)  renew,
          extend,  accelerate,  increase  the rate of interest  on, or otherwise
          change the time, place,  manner or terms of payment of the Obligations
          and/or  the  Indebtedness;   (ii)  settle,   compromise,   release  or
          discharge,  or accept or refuse any offer of performance  with respect
          to, or substitutions  for, the Obligations  and/or the Indebtedness or
          any agreement  relating thereto and/or  subordinate the payment of the
          same to the payment or  performance  of any other  obligations;  (iii)
          request and accept  other  guaranties  of the  Obligations  and/or the
          Indebtedness  and take  and  hold  security  for the  payment  of this
          Guaranty,  the  Obligations  and/or the  Indebtedness;  (iv)  release,
          surrender, exchange,  substitute,  compromise, settle, rescind, waive,
          alter,  subordinate  or  modify,  with or without  consideration,  any
          security for payment of the Obligations  and/or the Indebtedness,  any
          other guaranties of the Obligations  and/or the  Indebtedness,  or any
          other obligation of any Person with respect to the Obligations  and/or
          the  Indebtedness;  (v)enforce and apply any security now or hereafter
          held by or for the  benefit  of any  Beneficiary  in  respect  of this
          Guaranty or the Obligations  and/or  Indebtedness and direct the order
          or manner of sale thereof,  or exercise any other right or remedy that
          the  Beneficiaries  may  have  against  any  such  security,   as  the
          Beneficiaries,   in  their   discretion,   may  determine,   including
          foreclosure  on any such security  pursuant to one or more judicial or
          nonjudicial  sales,  whether  or not every  aspect of any such sale is
          commercially  reasonable,  and even  though  such  action  operates to
          impair or extinguish  any right of  reimbursement  or  subrogation  or
          other right or remedy of  Guarantor  against  Borrower or any security
          for the  Obligations  and/or the  Indebtedness;  and (vi) exercise any
          other  rights  and/or  remedies  available  to it under any  documents
          including the Loan Documents), at law or in equity.

(c)  This Guaranty and the obligations of Guarantor hereunder shall be valid and
     enforceable  and  shall  not  be  subject  to  any  reduction,  limitation,
     impairment, discharge or termination for any reason (other than the payment
     in  full  of  the  Obligations),  including  the  occurrence  of any of the
     following,  whether or not Guarantor  shall have had notice or knowledge of
     any of them: (i) any failure or omission to assert or enforce, or agreement
     or election not to assert or enforce, or the stay or enjoining, by order of
     court, by operation of law or otherwise, of the exercise or enforcement of,
     any claim or demand or any right,  power or remedy  (whether  arising under
     any  documents  (including  the  Loan  Documents),  at law,  in  equity  or
     otherwise) with respect to the Obligations  and/or the  Indebtedness or any
     agreement  relating  thereto,  or with respect to any other guaranty of, or
     security for, the payment of the Obligations and/or the Indebtedness;  (ii)
     any rescission,  waiver,  amendment or  modification  of, or any consent to
     departure from, any of the terms or provisions of any document  referred to
     herein,  (including  the  provisions  relating to "Events of  Default",  as
     defined in the Loan Documents) or of any other guaranty or security for the
     Obligations  and/or  the  Indebtedness,  in  each  case  whether  or not in
     accordance  with the  terms  thereof;  (iii)  the  Obligations  and/or  the
     Indebtedness, or any agreement relating thereto, at any time being found to
     be illegal,  invalid or unenforceable  in any respect;  (iv) any consent by

<PAGE>

     the  Beneficiaries  to the change,  reorganization  or  termination  of the
     structure or existence of Borrower;  (v) any failure to perfect or continue
     perfection of a security interest in any collateral that secures any of the
     Obligations  and/or  the  Indebtedness;  (vi)  any  defenses,  set-offs  or
     counterclaims that Borrower may allege or assert against any Beneficiary or
     could assert against any Beneficiary in respect of the  Obligations  and/or
     the Indebtedness,  including failure of consideration,  breach of warranty,
     statute of frauds,  statute of limitations,  accord and  satisfaction,  the
     doctrine of laches, equitable estoppel and usury; or (vii) any other act or
     thing or omission, or delay to do any other act or thing, that may or might
     in any manner or to any extent vary the risk of  Guarantor as an obligor in
     respect of the Guaranteed Obligations.

7.   Waivers by  Guarantor.  Guarantor  hereby  waives,  for the  benefit of the
     ---------------------
     Beneficiaries:

(a)  Any  right to  require  any  Beneficiary,  as a  condition  of  payment  by
     Guarantor,  (i) to proceed  against any other  guarantor of the Obligations
     and/or the  Indebtedness,  Borrower  or any other  Person,  (ii) to proceed
     against  or  exhaust  any  security  held from any other  guarantor  of the
     Obligations and/or the Indebtedness, Borrower or any other Person, (iii) to
     proceed  against or have resort to any  balance of any  deposit  account or
     credit on the books of the Beneficiaries in favor of any other guarantor of
     the Obligations  and/or the Indebtedness,  Borrower or any other Person, or
     (iv) to pursue any other remedy in the power of any Beneficiary whatsoever;

(b)  Any defense arising by reason of the  incapacity,  lack of authority or any
     disability or other defense of Borrower or any  Beneficiary,  including any
     defense   based  on  or  arising  out  of  the  lack  of  validity  or  the
     unenforceability   of  the  Obligations  and/or  the  Indebtedness  or  any
     agreement or instrument  relating  thereto or by reason of the cessation of
     the  liability of Borrower from any cause other than the payment in full of
     the Indebtedness;

(c)  Any defense  based upon any statute or rule of law that  provides  that the
     obligation  of a surety  must be  neither  larger  in  amount  nor in other
     respects more burdensome than that of the principal;

(d)  Any defense  based upon errors or  omissions  by the  Beneficiaries  in the
     administration of the Obligations and/or the Indebtedness;

(e)  Any  principles or provisions of law,  statutory or otherwise,  that are or
     might be in  conflict  with the  terms of this  Guaranty  and any  legal or
     equitable discharge of Guarantor's obligations hereunder;

(f)  Any  rights  to  set-offs,   recoupments  and  counterclaims   (other  than
     compulsory counterclaims);

(g)  Promptness,  diligence and any requirement that the Beneficiaries  protect,
     secure,  perfect or insure any  security  interest or lien or any  property
     subject thereto;

(h)  Notices, demands,  presentments,  demands for payment, protests, notices of
     protest,  notices  of  dishonor  and  notices  of any  action or  inaction,
     including acceptance of this Guaranty,  notices of default,  notices of any
     renewal,   extension  or  modification   of  the  Obligations   and/or  the
     Indebtedness or any agreement related thereto,  notices of any extension of
     credit to Borrower and notices of any of the matters referred to in Section
     6 and any right to consent to any of them, except to the extent provided in
     the Loan Documents;

(i)      Any  defenses or benefits  that may be derived  from or afforded by law
         that limit the liability of or exonerate Guarantor or sureties, or that
         may conflict with the terms of this Guaranty; and

(j)      The provisions of NRS 40.430 to the full extent provided for in NRS
         40.495(2).

8.   Guarantor's   Rights  of   Subrogation,   Contribution,   Etc.   Until  the
     -------------------------------------------------------------
     Indebtedness  shall have been  indefeasibly  paid in full,  Guarantor shall
     withhold  exercise of (a) any claim,  right or remedy,  direct or indirect,
     that Guarantor now has or may hereafter have against Borrower or any of its
     assets in connection  with this Guaranty or the performance by Guarantor of
     its obligations hereunder, in each case whether such claim, right or remedy
     arises in equity, under contract, by statute, under common law or otherwise
     and   including   (i)  any   right   of   subrogation,   reimbursement   or
     indemnification  that  Guarantor  now  has or may  hereafter  have  against
     Borrower, (ii) any right to enforce, or to participate in, any claim, right
     or remedy that the  Beneficiaries  now has or may  hereafter  have  against
     Borrower,  and (iii) any benefit of, and any right to  participate  in, any
     collateral or security now or hereafter held by the Beneficiaries,  and (b)
     any right of contribution Guarantor may have against any other guarantor of

<PAGE>

     the Obligations and/or the Indebtedness.  Guarantor further agrees that, to
     the  extent  the  waiver  of  its  rights  of  subrogation,  reimbursement,
     indemnification and contribution as set forth herein is found by a court of
     competent jurisdiction to be void or voidable for any reason, any rights of
     subrogation,  reimbursement or  indemnification  Guarantor may have against
     any of Borrower or against any  collateral  or security,  and any rights of
     contribution Guarantor may have against any such other guarantor,  shall be
     junior  and  subordinate  to any rights any  Beneficiary  may have  against
     Borrower to all right, title and interest the Beneficiaries may have in any
     such collateral or security.  Each  Beneficiary may use, sell or dispose of
     any item of  collateral  or security  as it sees fit without  regard to any
     subrogation  rights  Guarantor may have,  and upon any such  disposition or
     sale, any rights of subrogation Guarantor may have shall terminate.  If any
     amount  shall be paid to  Guarantor  on  account  of any such  subrogation,
     reimbursement or  indemnification  rights at any time when all Indebtedness
     shall not have been indefeasibly paid in full, such amount shall be held in
     trust  for the  Beneficiaries  and  shall  forthwith  be  paid  over to the
     Beneficiaries to be credited and applied against the Indebtedness,  whether
     matured or unmatured,  in accordance with the terms hereof.  The provisions
     of this  Section 8 shall  survive the release of the  Guarantor  under this
     Guaranty.

9.   Subordination of Other Obligations.  Guarantor hereby  subordinates any and
     ----------------------------------
     all  indebtedness  of Borrower  now or  hereafter  owed to Guarantor to all
     indebtedness  of  Borrower  to  any   Beneficiary,   and  agrees  with  the
     Beneficiaries  that  Guarantor  shall not demand or accept  any  payment of
     principal or interest  from  Borrower,  shall not claim any offset or other
     reduction  of  Guarantor's   obligations  hereunder  because  of  any  such
     indebtedness  and shall not take any action to obtain any of the collateral
     for the Loan;  provided  that,  the  Junior  Lender  shall be  entitled  to
     receive,  to the  extent  permitted  under  the  Loan  Agreement,  from the
     Borrower, payments in respect of the Junior Loan.

10.  Continuing  Guaranty.  This  Guaranty is a  continuing  guaranty  and shall
     --------------------
     remain  in effect  until  the  payment  in full of the  Obligations  or the
     Guaranteed  Obligations  (as  extended by the  provisions  of Section  11),
     whichever is sooner.

11.  Bankruptcy; Post-Petition Interest; Reinstatement of Guaranty.
     -------------------------------------------------------------
(a)  The  obligations  of Guarantor  under this  Guaranty  shall not be reduced,
     limited,  impaired,  discharged,  deferred,  suspended or terminated by any
     proceeding, voluntary or involuntary, involving the bankruptcy, insolvency,
     receivership,  reorganization, liquidation or arrangement of Borrower or by
     any  defense  that  Borrower  may have by  reason of the  order,  decree or
     decision of any court or  administrative  body resulting from any such case
     or proceeding.

(b)  Following  the  payment by any Person of all or any  portion of any payment
     obligations that are Guaranteed Obligations  hereunder,  the obligations of
     Guarantor  hereunder with respect thereto shall continue and remain in full
     force and effect or be  reinstated,  as the case may be, if all or any part
     of such payments are rescinded or recovered  directly or indirectly from as
     a  preference,  fraudulent  transfer or  otherwise in  connection  with any
     bankruptcy,   insolvency,   receivership,   reorganization,    liquidation,
     arrangement  or  similar  proceeding,  and any  such  payments  that are so
     rescinded or recovered  shall  constitute  Guaranteed  Obligations  for all
     purposes under this Guaranty.

(c)  Following a transfer of the Trust  Property  to any  Beneficiary  or to its
     designee,  the obligations of Guarantor  hereunder shall continue and shall
     remain in full  force and effect or be  reinstated,  as the case may be, if
     all or any part of such  transfer is  rescinded  or  recovered  directly or
     indirectly from such  Beneficiary as a preference,  fraudulent  transfer or
     otherwise in  connection  with any  bankruptcy,  insolvency,  receivership,
     reorganization, liquidation, arrangement or similar proceeding.

12.  Set Off. In addition to any other rights that the Beneficiaries may have at
     -------
     law or in equity,  if any amount  shall at any time be due and owing by any
     Guarantor to the Beneficiaries  under this Guaranty,  the Beneficiaries are
     authorized  at any time or from  time to time,  without  notice  (any  such
     notice being hereby expressly waived), to set off and to appropriate and to
     apply any and all indebtedness of the Beneficiaries  owing to Guarantor and
     any other  property of Guarantor  held by the  Beneficiaries  to or for the
     credit or the account of Guarantor against and on account of the Guaranteed
     Obligations  and liabilities of Guarantor to the  Beneficiaries  under this
     Guaranty.

<PAGE>

13.  Further  Assurances.  At any time or from time to time, upon the reasonable
     -------------------
     request of the  Beneficiaries,  Guarantor  shall  execute and deliver  such
     further  documents  and do such other acts and things as the  Beneficiaries
     may  reasonably  request  in order to  effect  fully the  purposes  of this
     Guaranty.

14.  General Provisions

     ------------------

(a)  Fully Recourse.  Notwithstanding any provisions of any other Loan Documents
     --------------
     to the  contrary,  all of the terms and  provisions  of this  Guaranty  are
     recourse  obligations  of Guarantor and not restricted by any limitation on
     personal liability.

(b)  Unsecured Obligations. Guarantor hereby acknowledges that the Lenders would
     ---------------------
     not make the Loan but for the unsecured  personal  liability  undertaken by
     Guarantor herein.

(c)  Rights  Cumulative;  Payments.  The  obligations of Guarantor  hereunder of
     -----------------------------
     Borrower  and the  Beneficiaries'  rights under this  Guaranty  shall be in
     addition to all rights of the  Beneficiaries  under the Notes,  the Deed of
     Trust and the other Loan Documents.  In the event of any default hereunder,
     a  separate  action  or  actions  may be  brought  and  prosecuted  against
     Guarantor whether or not Guarantor is the alter ego of Borrower and whether
     or not  Borrower  is joined  therein  or a separate  action or actions  are
     brought against Borrower.  The Beneficiaries' rights hereunder shall not be
     exhausted  until all of the  obligations  of Guarantor  hereunder have been
     fully paid and performed. TO THE EXTENT THAT PAYMENTS ARE MADE HEREUNDER BY
     GUARANTOR WITH RESPECT TO OBLIGATIONS AND LIABILITIES FOR WHICH BORROWER IS
     NOT LIABLE UNDER ANY NOTE,  THE DEED OF TRUST OR THE OTHER LOAN  DOCUMENTS,
     SUCH PAYMENTS MADE BY GUARANTOR UNDER THIS GUARANTY SHALL NOT REDUCE IN ANY
     RESPECT BORROWER'S  OBLIGATIONS AND LIABILITIES UNDER ANY NOTE, THE DEED OF
     TRUST OR THE OTHER LOAN DOCUMENTS, AND TO THE EXTENT THAT PAYMENTS ARE MADE
     HEREUNDER BY GUARANTOR  WITH RESPECT TO  OBLIGATIONS  AND  LIABILITIES  FOR
     WHICH  BORROWER  IS LIABLE  UNDER ANY NOTE,  THE DEED OF TRUST OR THE OTHER
     LOAN DOCUMENTS,  SUCH PAYMENTS SHALL BE APPLIED FIRST TO THOSE  OBLIGATIONS
     AND  LIABILITIES  ARISING  UNDER ANY NOTE,  THE DEED OF TRUST AND THE OTHER
     LOAN DOCUMENTS WITH RESPECT TO WHICH BORROWER IS NOT PERSONALLY LIABLE.

(d)  No Limitation on Liability.  Guarantor  hereby consents and agrees that the
     --------------------------
     Beneficiaries may at any time and from time to time without further consent
     from  Guarantor  do any of the  following  events,  and  the  liability  of
     Guarantor under this Guaranty shall be unconditional and absolute and shall
     in no way be impaired or limited by any of the  following  events,  whether
     occurring   with  or  without  notice  to  Guarantor  or  with  or  without
     consideration:  (i) any extensions of time for performance  required by any
     of the Loan Documents or otherwise  granted by any Beneficiary or extension
     or renewal of any Note;  (ii) any sale,  assignment or  foreclosure  of any
     Note,  the Deed of Trust or any of the other Loan  Documents or any sale or
     transfer  of the Trust  Property;  (iii) any change in the  composition  of
     Borrower,  including,  without  limitation,  the  withdrawal  or removal of
     Guarantor from any current or future  position of ownership,  management or
     control of Borrower; (iv) the accuracy or inaccuracy of the representations
     and warranties  made by Guarantor  herein or by Borrower in any of the Loan
     Documents;  (v) the release of  Borrower  or of any other  Person or entity
     from performance or observance of any of the agreements,  covenants,  terms
     or conditions  contained in any of the Loan  Documents by operation of law,
     any  Beneficiary's  voluntary  act  or  otherwise;   (vi)  the  release  or
     substitution  in whole or in part of any security  for the Loan;  (vii) the
     failure to record the Deed of Trust or to file any financing  statement (or
     the improper recording or filing thereof) or to otherwise perfect, protect,
     secure or insure any lien or security  interest  given as security  for the
     Loan;  (viii) the  modification  by the  Beneficiaries  and Borrower of the
     terms  of any one or more of the Loan  Documents;  or (ix)  the  taking  or
     failure to take any action of any type whatsoever. No such action which any
     Beneficiary  shall  take  or  fail to take  in  connection  with  the  Loan
     Documents or any  collateral  for the Loan,  nor any course or dealing with
     Borrower or any other Person,  shall limit,  impair or release  Guarantor's
     obligations hereunder,  affect this Guaranty in any way or afford Guarantor
     any recourse  against any  Beneficiary.  Nothing  contained in this Section
     shall be  construed  to require  any  Beneficiary  to take or refrain  from
     taking any action referred to herein.

<PAGE>


(e)  Attorneys' Fees. In the event it is necessary for any Beneficiary to retain
     ---------------
     the  services of an attorney or any other  consultants  in order to enforce
     this  Guaranty,  or any portion  thereof,  Guarantor  agrees to pay to such
     Beneficiary any and all reasonable costs and expenses,  including,  without
     limitation,  reasonable attorneys' fees, costs and disbursements,  incurred
     by such  Beneficiary as a result thereof and such costs,  fees and expenses
     shall be included in Costs.

(f)  Reliance.  The Lenders would not agree to make the Loan to Borrower without
     --------
     Guarantor entering into this Guaranty. Accordingly, Guarantor intentionally
     and  unconditionally  enters into the covenants and agreements as set forth
     above and understands  that, in reliance upon and in  consideration of such
     covenants  and  agreements,  the Loan shall be made and, as part and parcel
     thereof,  specific  monetary and other obligations have been, are being and
     shall be entered  into which would not be made or entered into but for such
     reliance.

(g)  Waiver  by  Guarantor.  Guarantor  covenants  and  agrees  that,  upon  the
     --------------------
     commencement  of a voluntary or  involuntary  bankruptcy  proceeding  by or
     against  Borrower,  Guarantor shall not seek or cause Borrower or any other
     Person or  entity  to seek a  supplemental  stay or other  relief,  whether
     injunctive  or  otherwise,  pursuant  to 11  U.S.C.ss.  105  or  any  other
     provision of the  Bankruptcy  Reform Act of 1978, as amended,  or any other
     debtor relief law, (whether  statutory,  common law, case law or otherwise)
     of any jurisdiction whatsoever, now or hereafter in effect, which may be or
     become applicable,  to stay,  interdict,  condition,  reduce or inhibit the
     ability of any Beneficiary to enforce any rights of any Beneficiary against
     Guarantor  or the  collateral  for the Loan by virtue of this  Guaranty  or
     otherwise.

(h)  Governing Law; Submission to Jurisdiction. (i) This Guaranty was negotiated
     -----------------------------------------
     in New York,  which State the parties agree has a substantial  relationship
     to the parties and to the underlying  transaction  embodied hereby,  and in
     all  respects  (including,  without  limitation,  matters of  construction,
     validity  and  performance),  this  Guaranty  and the  obligations  arising
     hereunder shall be governed by, and construed in accordance  with, the laws
     of the State of New York applicable to contracts made and performed in such
     State and any applicable law of the United States of America.

     (ii) Any legal  suit,  action or  proceeding  arising out of or relating to
          this  Guaranty may be  instituted in any federal or state court in New
          York, New York. The Guarantor  hereby (i) irrevocably  waives,  to the
          fullest extent permitted by applicable law, any objection which it may
          now or hereafter have to the laying of venue of any such suit,  action
          or  proceeding  brought  in such a court and any  claim  that any such
          proceeding brought in such a court has been brought in an inconvenient
          forum,  and (ii)  irrevocably  submits to the jurisdiction of any such
          court in any such  suit,  action or  proceeding.  The  Guarantor  does
          hereby designate and appoint Prentice-Hall Corporation System, Inc. as
          his authorized agent to accept and acknowledge on his behalf service
          of any and all process which may be served in any such suit, action or
          proceeding  in any federal or state court in New York,  New York,  and
          agrees  that  service  of  process  upon said agent with a copy to the
          Guarantor  at its address set forth below  (mailed or delivered to the
          Borrower  in the  manner  provided  herein)  shall be  deemed in every
          respect effective  service of process upon the Guarantor,  in any such
          suit, action or proceeding in the State of New York. The Guarantor (i)
          shall give prompt  notice to the  Administrative  Agent of any changed
          address of its authorized  agent  hereunder,  (ii) may at any time and
          from time to time  designate  a  substitute  authorized  agent with an
          office in New York,  New York (which office shall be designated as the
          address for service of process),  and (iii) shall  promptly  designate
          such a substitute if its authorized  agent ceases to have an office in
          New York, New York or is dissolved without leaving a successor.

     (i)  TRIAL BY JURY. EACH OF GUARANTOR AND EACH BENEFICIARY,  TO THE FULLEST
          EXTENT THAT IT MAY LAWFULLY DO SO,  WAIVES TRIAL BY JURY IN ANY ACTION
          OR PROCEEDING, INCLUDING, WITHOUT LIMITATION, ANY TORT ACTION, BROUGHT
          BY ANY PARTY  HERETO WITH  RESPECT TO THIS  GUARANTY,  ANY NOTE OR ANY
          OTHER LOAN  DOCUMENT.  BY THEIR  ACCEPTANCE  OF THIS  AGREEMENT,  EACH
          BENEFICIARY SHALL BE DEEMED TO HAVE AGREED TO SUCH WAIVER.

<PAGE>

(j)  Notices.  All notices,  demands,  consents,  approvals,  requests and other
     -------
     communications  required or permitted hereunder  ("Notices") shall be given
     in accordance  with the  provisions of Section 10.6 of the Loan  Agreement,
     provided that the Guarantor's address for Notices is as follows:

         c/o The Venetian
         3355 Las Vegas Boulevard South
         Las Vegas, NV  89109
         Telephone Number:  (702) 733-5500
         Facsimile Number:  (702) 733-5620

(k)  Guarantor  and  Beneficiaries  acknowledge  and agree  that  this  Guaranty
     supersedes  and  replaces in its entirety  that  certain  Guaranty put into
     escrow on November  14, 1997 made by Sheldon G. Adelson in favor of Goldman
     Sachs  Mortgage  Company and any other Lenders and which was intended to be
     replaced hereby.

<PAGE>

     IN WITNESS WHEREOF, Guarantor has duly executed this Guaranty as of the day
and year first above written.

                                                        /s/ Sheldon G. Adelson
                                                        -----------------------
                                                            SHELDON G. ADELSON




<PAGE>

State of New York )
     :
County of New York  )

On the ____ day of December, 1999, before me personally came SHELDON G. ADELSON,
to me known to be the  individual  described in and who  executed the  foregoing
instrument, and acknowledged that he executed the same.

                                                /s/
                                                --------------------------------
                                                          Notary Public
                                                          (Seal)
                                                          My Commission expires: