UNLIMITED GUARANTY


        GUARANTY,  dated as of  November  6,  1998 by GROVE  PROPERTY  TRUST,  a
Maryland  Real  Estate  Investment  Trust with a business  address at 598 Asylum
Avenue, Hartford,  Connecticut 06105 (the "GUARANTOR"),  in favor of BANKBOSTON,
N.A. a national  banking  association,  with an office at One  Landmark  Square,
Stamford, Connecticut 06901 (the "BANK"). In consideration of the Bank's giving,
in its  discretion,  time,  credit or banking  facilities or  accommodations  to
Gerald McNamara (the "CUSTOMER"), the Guarantor agrees as follows:

        1. GUARANTY OF PAYMENT AND PERFORMANCE.  The Guarantor hereby guarantees
to the Bank the full and punctual  payment  when due  (whether at  maturity,  by
acceleration or otherwise), and the performance, of all liabilities,  agreements
and other  obligations of the Customer to the Bank,  whether direct or indirect,
absolute or contingent, due or to become due, secured or unsecured, now existing
or hereafter arising or acquired (whether by way of discount,  letter of credit,
lease,  loan,  overdraft or otherwise)  arising under or in connection  with the
Revolving  Credit Agreement dated of even date herewith between the Customer and
the Bank (the "CREDIT  AGREEMENT")  or any document,  agreement  and  instrument
executed  in  connection  therewith  (collectively,  the  "OBLIGATIONS").   This
Guaranty is an absolute,  unconditional and continuing  guaranty of the full and
punctual   payment  and   performance  of  the  Obligations  and  not  of  their
collectibility  only and is in no way conditioned  upon any requirement that the
Bank first  attempts  to collect  any of the  Obligations  from the  Customer or
resort to any security or other means of  obtaining  their  payment.  Should the
Customer  default in the payment or performance of any of the  Obligations,  the
obligations of the Guarantor  hereunder shall become immediately due and payable
to the Bank,  without demand or notice of any nature, all of which are expressly
waived by the Guarantor.  Payments by the Guarantor hereunder may be required by
the Bank on any number of occasions.

        2. GUARANTOR'S  AGREEMENT TO PAY. The Guarantor further agrees to pay to
the  Bank,  on  demand,  all  costs  and  expenses  (including  court  costs and
reasonable  legal expenses)  incurred or expended by Bank in connection with the
Obligations,  this Guaranty and the enforcement thereof,  together with interest
on amounts recoverable under this Guaranty from the time such amounts become due
until payment, at the interest rate set forth in the Credit Agreement; provided,
that if such  interest  exceeds the maximum  amount  permitted  to be paid under
applicable  law, then such interest  shall be reduced to such maximum  permitted
amount.

        3. UNLIMITED GUARANTY. The liability of the Guarantor hereunder shall be
unlimited.

        4. WAIVERS BY GUARANTORS;  BANK'S  FREEDOM TO ACT. The Guarantor  agrees
that the Obligations will be paid and performed strictly in

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accordance  with their  respective  terms  regardless of any law,  regulation or
order now or hereafter in effect in any jurisdiction affecting any of such terms
or  the  rights  of  the  Bank  with  respect  thereto.   The  Guarantor  waives
presentment,  demand,  protest,  notice of  acceptance,  notice  of  Obligations
incurred and all other notices of any kind,  all defenses which may be available
by virtue of any  valuation,  stay,  moratorium  law or other similar law now or
hereafter  in effect,  any right to  require  the  marshalling  of assets of the
Customer, and all suretyship defenses generally. Without limiting the generality
of the  foregoing,  the Guarantor  agrees to the  provisions  of any  instrument
evidencing, securing or otherwise executed in connection with any Obligation and
agrees that the obligations of the Guarantor  hereunder shall not be released or
discharged, in whole or in part, or otherwise affected by (i) the failure of the
Bank to assert any claim or demand or to enforce any right or remedy against the
Customer;  (ii)  any  extensions  or  renewals  of  any  Obligation;  (iii)  any
rescissions,  waivers,  amendments  or  modifications  of any of  the  terms  or
provisions  of any  agreement  evidencing,  securing  or  otherwise  executed in
connection with any Obligation;  (iv) the  substitution or release of any entity
primarily  or  secondarily  liable  for  any  Obligation   (including,   without
limitation,  the release of the  Guarantor);  (v) the adequacy of any rights the
Bank may have against any  collateral  or other means of obtaining  repayment of
the Obligations; (vi) the impairment of any collateral securing the Obligations,
including  without  limitation the failure to perfect or preserve any rights the
Bank might have in such  collateral or the  substitution,  exchange,  surrender,
release,  loss or destruction of any such collateral;  or (vii) any other act or
omission  which  might  in any  manner  or to any  extent  vary  the risk of the
Guarantor or otherwise  operate as a release or discharge of the Guarantor,  all
of which may be done without notice to the Guarantor.

        5.  UNENFORCEABILITY OF OBLIGATIONS AGAINST CUSTOMER.  If for any reason
the Customer has no legal existence or is under no legal obligation to discharge
any of the Obligations,  or if any of the Obligations have become  irrecoverable
from such  Customer by operation of law or for any other  reason,  this Guaranty
shall  nevertheless  be binding on the  Guarantor  to the same  extent as if the
Guarantor at all times had been the principal  obligor on all such  Obligations.
In the event that  acceleration  of the time for payment of the  Obligations  is
stayed upon the insolvency, bankruptcy or reorganization of the Customer, or for
any other reason,  all such amounts otherwise subject to acceleration  under the
terms of any agreement evidencing,  securing or otherwise executed in connection
with any Obligation shall be immediately due and payable by the Guarantor.

        6. SUBROGATION; SUBORDINATION. Until the payment and performance in full
of all  Obligations and any and all obligations of the Customer to any affiliate
of the Bank,  the Guarantor  shall not exercise any rights  against the Customer
arising as a result of payment by the Guarantor hereunder, by way of subrogation
or otherwise,  and will not prove any claim in competition  with the Bank or its
affiliates  in respect of any payment  hereunder  in  bankruptcy  or  insolvency
proceedings of any nature; until the payment and

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performance  of all of the  Obligations  and  any  and  all  Obligations  of the
Customer to any affiliate of the Bank,  the Guarantor will not claim any set-off
or  counterclaim  against  the  Customer  in  respect  of any  liability  of the
Guarantor to the Customer; and the Guarantor waives any benefit of and any right
to  participate  in any  collateral  which  may be held by the  Bank or any such
affiliate.  The payment of any amounts due with respect to any  indebtedness  of
the Customer now or hereafter  held by the Guarantor is hereby  subordinated  to
the prior  payment in full of the  Obligations.  The  Guarantor  agrees that the
Guarantor  will not  demand,  sue for or  otherwise  attempt to collect any such
indebtedness of the Customer to the Guarantor  until the Obligations  shall have
been paid in full. If,  notwithstanding  the foregoing  sentence,  the Guarantor
shall collect,  enforce or receive any amounts in respect of such  indebtedness,
such amounts  shall be  collected,  enforced  and  received by the  Guarantor as
trustee for the Bank and be paid over to the Bank on account of the  Obligations
without  affecting in any manner the liability of the Guarantor  under the other
provisions of this Guaranty.

        7.  SECURITY;  SET-OFF.  The  Guarantor  hereby  grants to the Bank,  as
security for the full and punctual  payment and  performance of the  Guarantor's
obligations  hereunder,  a  continuing  lien  on and  security  interest  in all
securities or other property belonging to the Guarantor now or hereafter held by
the Bank and in all deposits (general or special, time or demand, provisional or
final)  and other  sums  credited  by or due from the Bank to the  Guarantor  or
subject to withdrawal by the  Guarantor;  and  regardless of the adequacy of any
collateral or other means of obtaining repayment of the Obligations, the Bank is
hereby  authorized at any time and from time to time during the continuance of a
Default or an event of Default, without notice to the Guarantor (any such notice
being expressly  waived by the Guarantor) and to the fullest extent permitted by
law, to set off and apply such  deposits and other sums against the  obligations
of the Guarantor  under this  Guaranty,  whether or not the Bank shall have made
any demand under this Guaranty and although such  obligations  may be contingent
or unmatured.

        8. FURTHER  ASSURANCES.  The Guarantor  agrees to do all such things and
execute  all  such  documents,  including  financing  statements,  which  may be
reasonably  necessary or  desirable to give full effect to this  Guaranty and to
protect and preserve the rights and powers of the Bank hereunder.

        9. TERMINATION;  REINSTATEMENT. This Guaranty shall remain in full force
and effect until the payment in full of the  Obligations.  This  Guaranty  shall
continue to be  effective  or be  reinstated  if at any time any payment made or
value  received with respect to an Obligation is rescinded or must  otherwise be
returned by the Bank upon the insolvency,  bankruptcy or  reorganization  of any
Customer,  or  otherwise,  all as though such payment had not been made or value
received.

        10.  SUCCESSORS  AND ASSIGNS.  This  Guaranty  shall be binding upon the
Guarantor, and its respective heirs, trustees, successors and assigns,

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and  shall  inure  to the  benefit  of and be  enforceable  by the  Bank and its
successors,  transferees  and assigns.  Without  limiting the  generality of the
foregoing  sentence,  the Bank may assign or otherwise transfer any agreement or
any note held by it  evidencing,  securing or otherwise  executed in  connection
with the Obligations,  or sell  participations in any interest  therein,  to any
other person or entity,  and such other person or entity shall thereupon  become
vested,  to the extent set forth in the agreement  evidencing  such  assignment,
transfer or participation, with all the rights in respect thereof granted to the
Bank herein.

        11.  AMENDMENTS AND WAIVERS.  No amendment or waiver of any provision of
this Guaranty nor consent to any departure by the Guarantor  therefrom  shall be
effective unless the same shall be in writing and signed by the Bank. No failure
on the part of the Bank to  exercise,  and no delay  in  exercising,  any  right
hereunder  shall  operate as a waiver  thereof;  nor shall any single or partial
exercise of any right hereunder  preclude any other or further  exercise thereof
or the exercise of any other right.

        12. NOTICES. All notices and other  communications  called for hereunder
shall be made in writing and, unless  otherwise  specifically  provided  herein,
shall be  deemed  to have  been  duly  made or  given  when  delivered  by hand,
overnight  mail or mailed first class  certified  mail postage  prepaid,  return
receipt requested, addressed as follows: if to the Guarantor, at the address set
forth  beneath  its  respective  signature  hereto,  and if to the Bank,  at One
Landmark Square, 7th Floor, Stamford, Connecticut 06901, Attention: Christina P.
Clark, or at such address as either party may designate in writing.

        13.  GOVERNING  LAW;  CONSENT TO  JURISDICTION.  This Guaranty  shall be
governed  by,  and  construed  in  accordance  with,  the  laws of the  State of
Connecticut.  The  Guarantor  agrees that any suit for the  enforcement  of this
Guaranty may be brought in the courts of the State of Connecticut or any Federal
Court sitting  therein and consents to the  non-exclusive  jurisdiction  of such
court and to service  of process in any such suit being made upon the  Guarantor
by mail at the addresses  specified in Section 12 hereof.  The Guarantor  hereby
waives any objection  that it may now or hereafter have to the venue of any such
suit or any such court or that such suit was brought in an inconvenient court.

        14. MISCELLANEOUS. This Guaranty constitutes the entire agreement of the
Guarantor with respect to the matters set forth herein.  The rights and remedies
herein provided are cumulative and not exclusive of any remedies provided by law
or any other  agreement,  and this  Guaranty  shall be in  addition to any other
guaranty of the Obligations.  The invalidity or  unenforceability  of any one or
more sections of this Guaranty  shall not affect the validity or  enforceability
of its  remaining  provisions.  Captions are for the ease of reference  only and
shall not affect the meaning of the  relevant  provisions.  The  meanings of all
defined terms used in this Guaranty shall be equally  applicable to the singular
and plural forms of the terms defined.



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        15. GUARANTOR'S REPRESENTATIONS AND WARRANTIES. The Guarantor represents
and warrants to the Bank as follows:

               (a)  Incorporation;   Good  Standing.  The  Guarantor  (i)  is  a
        corporation duly organized,  validly existing and in good standing under
        the laws of its state of incorporation, (ii) has all requisite corporate
        power to own its property and conduct its business as now  conducted and
        as presently  contemplated,  and (iii) is in good  standing as a foreign
        corporation and is duly  authorized to do business in each  jurisdiction
        where such  qualification  is necessary  except where a failure to be so
        qualified  would not have a materially  adverse  effect on the business,
        assets or financial condition of the Guarantor.

               (b)  Authorization.  The execution,  delivery and  performance of
        this Guaranty and the transactions  contemplated  hereby and thereby (i)
        are  within  the  authority  of  the  Guarantor,  (ii)  have  been  duly
        authorized by all necessary  proceedings,  (iii) do not conflict with or
        result in any breach or contravention of any provision of law,  statute,
        rule or  regulation  to which the  Guarantor is subject or any judgment,
        order, writ, injunction,  license or permit applicable to the Guarantor,
        (iv) do not  conflict  with any  provision of the  corporate  charter or
        bylaws of the  Guarantor  and (v) do not conflict  with any agreement or
        instrument  binding upon the Guarantor  except where such conflict would
        not have a material adverse effect on the business,  assets or financial
        condition of the Guarantor, considered as a whole.

               (c)  Enforceability.  The  execution and deliver of this Guaranty
        will result in valid and legally  binding  obligations  of the Guarantor
        enforceable  against  it in  accordance  with the  respective  terms and
        provisions  hereof except as  enforceability  is limited by  bankruptcy,
        insolvency,  reorganization,  moratorium  or other laws  relating  to or
        affecting  generally the enforcement of creditors'  rights and except to
        the extent that  availability  of the remedy of specific  performance or
        injunctive  relief is  subject to  general  principles  of equity or the
        discretion  of the court  before  which any  proceeding  therefor may be
        brought.

               (d) Financial Statements.  There has been furnished to the Bank a
        consolidated  balance sheet of the Guarantor as at June 30, 1998,  and a
        consolidated  statement of income of the  Guarantor  for the fiscal year
        then ended, certified by Ernst & Young. Such balance sheet and statement
        of income  have been  prepared in  accordance  with  generally  accepted
        accounting  principles and fairly present the financial condition of the
        Guarantor  as the close of business on the date  thereof and the results
        of  operations  for the fiscal year then ended.  There are no contingent
        liabilities of the Guarantor as of such date involving material amounts,
        known to the  Guarantor,  which were not disclosed in such balance sheet
        and the notes related thereto.



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               (e) No Material  Changes,  Etc.  Since June 30,  1998,  there has
        occurred no  materially  adverse  change in the  financial  condition or
        business of the  Guarantor as shown on or reflected in the  consolidated
        balance  sheet of the  Guarantor  as at such date,  or the  consolidated
        statement  of income for the fiscal year then ended,  other than changes
        in the  ordinary  course of  business  that have not had any  materially
        adverse effect either  individually  or in the aggregate on the business
        or financial condition of the Guarantor, taken as a whole.

        16. COVENANTS.  The Guarantor hereby covenants to the Bank that, so long
as any of the Obligations remain outstanding or this Guaranty remains in effect,
the Guarantor  will furnish to the Bank (i) copies of the financial  information
required  under ss.7(a) of the Grove Credit  Agreement (as defined in the Credit
Agreement) and (ii) together with such financial information, a copy of the most
recent 10K filed with the  Securities  and  Exchange  Commission  detailing  the
current  salary and prior year bonuses (paid or deferred) of the Customer,  such
financial information to be delivered on or before May 1 of each calendar year.

        17. WAIVER OF JURY TRIAL; CONSENT TO JURISDICTION.  The Guarantor hereby
waives the Guarantor's  right to a jury trial with respect to: (i) any action or
claim arising out of any dispute in connection with this Guaranty, any rights or
obligations  hereunder or the performance of such rights and  obligations;  and,
(ii) any  action or claim  arising  out of any  dispute in  connection  with the
Credit Agreement or any document, agreement or instrument executed in connection
therewith (collectively,  with the Credit Agreement and this Guaranty, the "LOAN
DOCUMENTS").  Except as prohibited by law, the Guarantor hereby waives any right
the Guarantor may have to claim or recover in any litigation  referred to in the
preceding sentence any special, exemplary,  punitive or consequential damages or
any damages  other than, or in addition to,  actual  damages.  The Guarantor (a)
certifies that no representative, agent or attorney of the Bank has represented,
expressly  or  otherwise,  that the Bank would not, in the event of  litigation,
seek to enforce the foregoing  waivers and (b)  acknowledges  that the Bank have
been induced to give credit to such Customer by, among other things, the waivers
and certifications contained herein.

        The Guarantor hereby further agrees that the following courts: (i) State
Court-any  state or local court of the State of  Connecticut;  and (ii)  Federal
Court-United  States District Court for the District of  Connecticut,  or at the
option  of the  Bank,  any  court in  which  the Bank  shall  initiate  legal or
equitable  proceedings  and which has subject  matter and personal  jurisdiction
over the matter and parties in controversy, shall have exclusive jurisdiction to
hear and determine any claims or disputes  between the  undersigned and the Bank
pertaining directly or indirectly to the Loan Documents or to any matter arising
therefrom.  The  Guarantor  expressly  submits  and  consents in advance to such
jurisdiction  in any  action or  proceeding  commenced  in such  courts,  hereby
waiving personal service of the summons and complaint, or other process or

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papers issued therein,  and agreeing that service of such summons and complaint,
or other process or papers,  may be made by registered or certified mail, return
receipt requested,  addressed to the undersigned at the address set forth below.
Should the Guarantor fail to appear or answer any summons, complaint, process or
papers  so served  within  thirty  (30) days  after  the  mailing  thereof,  the
Guarantor shall be deemed in default and an order and/or judgment may be entered
against the  Guarantor  as demanded  or prayed for in such  summons,  complaint,
process or papers.

        The exclusive  choice of forum set forth in this  Guaranty  shall not be
deemed to preclude the enforcement of any judgment obtained in such forum or the
taking  of any  action  under  the Loan  Documents  to  enforce  the same in any
appropriate jurisdiction.

        18. PREJUDGMENT REMEDY WAIVER; OTHER WAIVERS. THE GUARANTOR ACKNOWLEDGES
THAT THIS  GUARANTY IS PART OF A  COMMERCIAL  TRANSACTION  WITHIN THE MEANING OF
CHAPTER 903a OF THE CONNECTICUT  GENERAL  STATUTES.  THE GUARANTOR HEREBY WAIVES
THE  GUARANTOR'S  RIGHT TO NOTICE AND PRIOR  COURT  HEARING OR COURT ORDER UNDER
CONNECTICUT  GENERAL STATUTES  SECTIONS 52-278a ET. SEQ. AS AMENDED OR UNDER ANY
OTHER STATE OR FEDERAL LAW WITH RESPECT TO ANY AND ALL PREJUDGMENT  REMEDIES THE
BANK MAY EMPLOY TO ENFORCE ITS RIGHTS AND REMEDIES HEREUNDER. MORE SPECIFICALLY,
THE GUARANTOR  ACKNOWLEDGES THAT THE BANK'S ATTORNEY MAY, PURSUANT TO CONN. GEN.
STAT. ss.52-278F, ISSUE A WRIT FOR A PREJUDGMENT REMEDY WITHOUT SECURING A COURT
ORDER. THE GUARANTOR  ACKNOWLEDGES AND RESERVES THE GUARANTOR'S  RIGHT TO NOTICE
AND A HEARING  SUBSEQUENT  TO THE ISSUANCE OF A WRIT FOR  PREJUDGMENT  REMEDY AS
AFORESAID  AND THE BANK  ACKNOWLEDGES  THE  GUARANTOR'S  RIGHT  TO SAID  HEARING
SUBSEQUENT TO THE ISSUANCE OF SAID WRIT.

        IN WITNESS  WHEREOF,  the  Guarantor  has  caused  this  Guaranty  to be
executed and delivered as of the date first appearing above.


                                      GROVE PROPERTY TRUST


                                      By: /s/Joseph R. LaBrosse
                                          -----------------------------
                                          Name:  Joseph R. LaBrosse
                                          Title: Chief Financial Officer

                                             Address:  598 Asylum Avenue
                                                       Hartford, CT 06105
                                             Telephone: (860) 246-1126
                                             Telecopy:  (860) 527-0401