Exhibit 4.7


                               GUARANTEE AGREEMENT

                                     between


                                HSB GROUP, INC.,
                                  as Guarantor


                                       and


                       THE FIRST NATIONAL BANK OF CHICAGO,
                              as Guarantee Trustee


                                   Relating to

                                 HSB Capital II


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



                          Dated as of December 31, 1997


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











                               TABLE OF CONTENTS
                                                                      Page


                                   ARTICLE I

                                  DEFINITIONS

SECTION 1.1. Definitions.....................................................  2

                    ARTICLE II

                TRUST INDENTURE ACT

SECTION 2.1. Trust Indenture Act; Application................................  5
SECTION 2.2. List of Holders.................................................  5
SECTION 2.3. Reports by the Guarantee Trustee................................  5
SECTION 2.4. Periodic Reports to the Guarantee Trustee.......................  6
SECTION 2.5. Evidence of Compliance with Conditions Precedent................  6
SECTION 2.6. Events of Default; Waiver.......................................  6
SECTION 2.7. Event of Default; Notice........................................  6
SECTION 2.8. Conflicting Interests...........................................  7


                    ARTICLE III

POWERS, DUTIES AND RIGHTS OF THE GUARANTEE TRUSTEE

SECTION 3.1. Powers and Duties of the Guarantee Trustee......................  7
SECTION 3.2. Certain Rights of Guarantee Trustee.............................  8
SECTION 3.3. Compensation; Fees.............................................. 10


                    ARTICLE IV

                 GUARANTEE TRUSTEE

SECTION 4.1. Guarantee Trustee; Eligibility.................................. 11
SECTION 4.2. Appointment, Removal and Resignation of the Guarantee Trustee... 11


                        -i-






                                    ARTICLE V

                                    GUARANTEE

 SECTION 5.1. Guarantee..................................................... 12
 SECTION 5.2. Waiver of Notice and Demand................................... 12
 SECTION 5.3. Obligations Not Affected...................................... 12
 SECTION 5.4. Rights of Holders............................................. 13
 SECTION 5.5. Guarantee of Payment.......................................... 14
 SECTION 5.6. Subrogation................................................... 14
 SECTION 5.7. Independent Obligations....................................... 14


                                   ARTICLE VI

                           COVENANTS AND SUBORDINATION

 SECTION 6.1. Subordination................................................. 14
 SECTION 6.2. Pari Passu Guarantees......................................... 15


                                   ARTICLE VII

                                   TERMINATION

 SECTION 7.1. Termination................................................... 15


                                  ARTICLE VIII

                                  MISCELLANEOUS

 SECTION 8.1. Successors and Assigns........................................ 16
 SECTION 8.2. Amendments.................................................... 16
 SECTION 8.3. Notices....................................................... 16
 SECTION 8.4. Benefit....................................................... 17
 SECTION 8.5. Governing Law................................................. 17
 SECTION 8.6. Counterparts.................................................. 17


                                      -ii-






         GUARANTEE AGREEMENT,  dated as of December 31, 1997, between HSB GROUP,
INC., a Connecticut  corporation (the "Guarantor"),  having its principal office
at One State Street, Hartford,  Connecticut 06102 and The First National Bank of
Chicago, a national banking association,  as trustee (the "Guarantee  Trustee"),
for the  benefit of the Holders  (as  defined  herein)  from time to time of the
Capital  Securities (as defined herein) of HSB Capital II, a Delaware  statutory
business trust (the "Issuer Trust").

                           RECITALS OF THE CORPORATION

         WHEREAS,  pursuant to a Trust Agreement,  dated as of December 31, 1997
(the "Trust Agreement"), among HSB Group, Inc., as Depositor, The First National
Bank of Chicago,  as Property  Trustee,  First Chicago Delaware Inc. as Delaware
Trustee,  and the  Administrative  Trustees named  therein,  the Issuer Trust is
issuing  $300,000,000  aggregate  Liquidation  Amount  (as  defined in the Trust
Agreement) of its Convertible Capital Securities  (liquidation amount $1,000 per
capital security) (the "Capital  Securities"),  representing preferred undivided
beneficial  interests in the assets of the Issuer Trust and having the terms set
forth in the Trust Agreement; and

         WHEREAS,  the Capital Securities will be issued by the Issuer Trust and
the proceeds thereof, together with the proceeds from the issuance of the Issuer
Trust's  Common  Securities  (as defined  herein),  will be used to purchase the
Debentures  (as  defined  in  the  Trust  Agreement)  of  the  Guarantor,  which
Debentures  will be  deposited  with The  First  National  Bank of  Chicago,  as
Property Trustee under the Trust Agreement, as trust assets; and

         WHEREAS,   as  an  incentive  for  the  Holders  to  purchase   Capital
Securities,  the Guarantor desires  irrevocably and unconditionally to agree, to
the extent set forth herein, to pay to the Holders of the Capital Securities the
Guarantee  Payments (as defined  herein) on the terms and  conditions  set forth
herein.

         WHEREAS,   the  Guarantor  is  executing  and  delivering  a  guarantee
agreement (the "Common  Securities  Guarantee"),  with  substantially  identical
terms to this Guarantee Agreement,  for the benefit of the holders of the Common
Securities (as defined  herein),  except that if an Event of Default (as defined
in the Declaration) has occurred and is continuing, the rights of holders of the
Common  Securities to receive  Guarantee  Payments  under the Common  Securities
Guarantee  are  subordinated,  to the  extent and in the manner set forth in the
Common Securities  Guarantee,  to the rights of holders of Capital Securities to
receive Guarantee Payments under this Guarantee Agreement.

         NOW, THEREFORE,  in consideration of the purchase of Capital Securities
by each Holder,  which purchase the Guarantor hereby  acknowledges  will benefit
the Guarantor,  the Guarantor executes and delivers this Guarantee Agreement for
the benefit of the Holders from time to time.









                                    ARTICLE I

                                   DEFINITIONS

         SECTION 1.1. Definitions.

         For all  purposes  of this  Guarantee  Agreement,  except as  otherwise
expressly provided or unless the context otherwise requires:

         (a) The terms  defined in this Article  have the  meanings  assigned to
them in this Article, and include the plural as well as the singular;

         (b) All other terms used herein that are defined in the Trust Indenture
Act, either directly or by reference therein, have the meanings assigned to them
therein;

         (c) The words "include", "includes" and "including" shall be deemed to
be followed by the phrase "without limitation";

         (d) All accounting  terms used but not defined herein have the meanings
assigned to them in accordance with United States generally accepted  accounting
principles;

         (e)  Unless  the  context  otherwise  requires,  any  reference  to  an
"Article" or a "Section" refers to an Article or a Section,  as the case may be,
of this Guarantee Agreement; and

         (f) The words  "hereby",  "herein",  "hereof" and "hereunder" and other
words of similar import refer to this Guarantee  Agreement as a whole and not to
any particular Article, Section or other subdivision.

         "Affiliate" of any specified  Person means any other Person directly or
indirectly  controlling  or  controlled  by or under  direct or indirect  common
control  with  such  specified  Person.  For the  purposes  of this  definition,
"control",  when used with respect to any specified  Person,  means the power to
direct the  management  and  policies of such  Person,  directly or  indirectly,
whether  through the ownership of voting  securities,  by contract or otherwise;
and the terms  "controlling" and "controlled"  have meanings  correlative to the
foregoing.

         "Board of  Directors"  means the board of directors of the Guarantor or
the Executive Committee of the board of directors of the Guarantor (or any other
committee  of the  board  of  directors  of  the  Guarantor  performing  similar
functions) or a committee  designated by the board of directors of the Guarantor
(or such committee),  comprised of two or more members of the board of directors
of the Guarantor or officers of the Guarantor, or both.

         "Capital  Securities" means the capital  securities of the Issuer Trust
defined in the Trust  Agreement  referred to in the  recitals to this  Guarantee
Agreement, as modified, amended or supplemented from time to time.

                                       -2-







         "Common Securities" means the securities  representing common undivided
beneficial interests in the assets of the Issuer Trust.

         "Event of Default"  means (i) a default by the  Guarantor in any of its
payment  obligations  under this  Guarantee  Agreement  or (ii) a default by the
Guarantor in any material respect of any other obligation hereunder that remains
unremedied for 90 days.

         "Guarantee  Agreement"  means this  Guarantee  Agreement,  as modified,
amended or supplemented from time to time.

         "Guarantee  Payments"  means the following  payments or  distributions,
without duplication,  with respect to the Capital Securities,  to the extent not
paid or made by or on behalf of the Issuer  Trust:  (i) any  accrued  and unpaid
Distributions  required to be paid on the Capital Securities,  to the extent the
Issuer  Trust  has  funds on hand  available  therefor  at such  time,  (ii) the
Redemption Price with respect to any Capital  Securities  called for redemption,
to the extent  the Issuer  Trust has funds on hand  available  therefor  at such
time,  and (iii) upon a  voluntary  or  involuntary  termination,  winding up or
liquidation of the Issuer Trust (unless the  Debentures  are  distributed to the
Holders) the lesser of (a) the Liquidation Distribution (as defined in the Trust
Agreement) with respect to the Capital Securities,  and (b) the amount of assets
of  the  Issuer  Trust  remaining  available  for  distribution  to  Holders  on
liquidation of the Issuer Trust.

         "Guarantee Trustee" means The First National Bank of Chicago, solely in
its capacity as Guarantee  Trustee and not in its individual  capacity,  until a
Successor Guarantee Trustee has been appointed and has accepted such appointment
pursuant to the terms of this Guarantee  Agreement,  and  thereafter  means each
such Successor Guarantee Trustee.

     "Guarantor"  has the  meaning  specified  in the  first  paragraph  of this
Guarantee Agreement.

         "Holder"  means any Holder (as defined in the Trust  Agreement)  of any
Capital Securities;  provided,  however, that in determining whether the holders
of the  requisite  percentage  of Capital  Securities  have  given any  request,
notice,  consent or waiver hereunder,  "Holder" shall not include the Guarantor,
the  Guarantee  Trustee,  or any  Affiliate of the  Guarantor  or the  Guarantee
Trustee.

         "Indenture" means the Indenture, dated as of December 31, 1997, between
HSB Group, Inc. and The First National Bank of Chicago,  as trustee, as the same
may be modified, amended or supplemented from time to time.

         "Issuer Trust" has the meaning specified in the first paragraph of 
this Guarantee Agreement.


                                                          -3-






         "List of Holders" has the meaning specified in Section 2.2(a).

         "Majority  in  Liquidation  Amount of the  Capital  Securities"  means,
except as provided by the Trust Indenture Act, Capital  Securities  representing
more than 50% of the  aggregate  Liquidation  Amount  (as  defined  in the Trust
Agreement) of all Capital  Securities then  Outstanding (as defined in the Trust
Agreement).

         "Officers' Certificate" means a certificate signed by one of the Senior
Vice Presidents or Chief  Executive  Officer or the President or Vice Presidents
of the Guarantor,  and by the Treasurer,  an Assistant Treasurer,  the Corporate
Secretary or an Assistant Corporate Secretary of the Guarantor, and delivered to
the Guarantee  Trustee.  Any  Officers'  Certificate  delivered  with respect to
compliance with a condition or covenant provided for in this Guarantee Agreement
shall include:

                  (a)  a  statement  by  each  officer   signing  the  Officers'
         Certificate  that such officer has read the  covenant or condition  and
         the definitions relating thereto;

                  (b)  a  brief  statement  of  the  nature  and  scope  of  the
         examination  or  investigation  undertaken by such officer in rendering
         the Officers' Certificate;

                  (c) a statement that such officer has made such examination or
         investigation  as, in such  officer's  opinion,  is necessary to enable
         such  officer to express an informed  opinion as to whether or not such
         covenant or condition has been complied with; and

                  (d) a statement as to whether, in the opinion of such officer,
         such condition or covenant has been complied with.

         "Person" means a legal person,  including any individual,  corporation,
estate, partnership,  joint venture, association,  joint-stock company, company,
limited liability company, trust, business trust, unincorporated association, or
government or any agency or political  subdivision  thereof, or any other entity
of whatever nature.

         "Responsible Officer" means, with respect to the Guarantee Trustee, any
Senior Vice  President,  any Vice President,  any Assistant Vice President,  the
Secretary,  any Assistant Secretary, the Treasurer, any Assistant Treasurer, any
Trust  Officer or Assistant  Trust Officer or any other officer of the Corporate
Trust  Department  of the  Guarantee  Trustee and also means,  with respect to a
particular  matter, any other officer to whom such matter is referred because of
that officer's knowledge of and familiarity with the particular subject.

         "Successor  Guarantee  Trustee"  means a  successor  Guarantee  Trustee
possessing the qualifications to act as Guarantee Trustee under Section 4.1.

         "Trust  Agreement"  means  the  Trust  Agreement  of the  Issuer  Trust
referred to in the recitals to this Guarantee Agreement, as modified, amended or
supplemented from time to time.

                                                          -4-







         "Trust Indenture Act" means the Trust Indenture Act of 1939 as in force
at the  date as of  which  this  Guarantee  Agreement  was  executed;  provided,
however,  that if the Trust  Indenture  Act of 1939 is amended  after such date,
"Trust  Indenture Act" means, to the extent required by any such amendment,  the
Trust Indenture Act of 1939 as so amended.


                                   ARTICLE II

                               TRUST INDENTURE ACT

         SECTION 2.1. Trust Indenture Act; Application.

         Except as otherwise  expressly provided herein, the Trust Indenture Act
shall apply as a matter of contract to this Guarantee  Agreement for purposes of
interpretation,  construction and defining the rights and obligations hereunder,
and this Guarantee  Agreement,  the Guarantor and the Guarantee Trustee shall be
deemed  for all  purposes  hereof to be  subject  to and  governed  by the Trust
Indenture  Act to the  same  extent  as  would  be the  case if  this  Guarantee
Agreement were qualified under that Act on the date hereof.  Except as otherwise
expressly  provided  herein,  if and to the extent  that any  provision  of this
Guarantee  Agreement  limits,  qualifies or conflicts with the duties imposed by
Sections 310 to 317, inclusive,  of the Trust Indenture Act, such imposed duties
shall control.

         SECTION 2.2. List of Holders.

         (a) Commencing July 1, 1998, the Guarantor shall furnish or cause to be
furnished to the Guarantee Trustee (a) semi-annually, on or before January 1 and
July 1 of  each  year,  a list,  in  such  form  as the  Guarantee  Trustee  may
reasonably  require,  of the  names and  addresses  of the  Holders  (a "List of
Holders") as of a date not more than 15 days prior to the delivery thereof,  and
(b) at such other times as the Guarantee Trustee may request in writing,  within
30 days  after the  receipt  by the  Guarantor  of any such  request,  a List of
Holders  as of a date not more  than 15 days  prior  to the  time  such  list is
furnished,  in each case to the extent such  information is in the possession or
control of the Guarantor  and has not  otherwise  been received by the Guarantee
Trustee in its capacity as such.  The Guarantee  Trustee may destroy any List of
Holders previously given to it on receipt of a new List of Holders.

         (b) The Guarantee Trustee shall comply with the requirements of Section
311(a), Section 311(b) and Section 312(b) of the Trust Indenture Act.

         SECTION 2.3. Reports by the Guarantee Trustee.

         Not later than 60 days  following May 15 of each year,  commencing  May
15, 1998, the Guarantee Trustee shall provide to the Holders such reports as are
required by Section 313 of the Trust  Indenture  Act, if any, in the form and in
the manner provided by Section 313 of the Trust Indenture Act. If this Guarantee
Agreement shall have been qualified under the Trust

                                       -5-






Indenture Act, the Guarantee  Trustee shall also comply with the requirements of
Section 313(d) of the Trust Indenture Act.

         SECTION 2.4. Periodic Reports to the Guarantee Trustee.

         The Guarantor  shall  provide to the Guarantee  Trustee and the Holders
such documents,  reports and information,  if any, as required by Section 314 of
the Trust Indenture Act and the compliance  certificate  required by Section 314
of the Trust Indenture Act, in the form, in the manner and at the times required
by Section 314 of the Trust Indenture Act, provided that such documents, reports
and  information  shall not be required to be  provided  to the  Securities  and
Exchange  Commission  unless this Guarantee  Agreement shall have been qualified
under the Trust Indenture Act.

         SECTION 2.5. Evidence of Compliance with Conditions Precedent.

         The Guarantor  shall provide to the Guarantee  Trustee such evidence of
compliance  with  such  conditions  precedent,  if  any,  provided  for in  this
Guarantee  Agreement  that  relate to any of the  matters  set forth in  Section
314(c) of the Trust  Indenture Act. Any  certificate  or opinion  required to be
given by an officer of the Guarantor  pursuant to Section 314(c)(1) may be given
in the form of an Officers' Certificate.

         SECTION 2.6. Events of Default; Waiver.

         The Holders of at least a Majority in Liquidation Amount of the Capital
Securities may, by vote, on behalf of the Holders of all the Capital Securities,
waive any past  default  or Event of  Default  and its  consequences.  Upon such
waiver,  any such  default or Event of  Default  shall  cease to exist,  and any
default  or Event of  Default  arising  therefrom  shall be  deemed to have been
cured, for every purpose of this Guarantee  Agreement,  but no such waiver shall
extend to any  subsequent  or other  default  or Event of  Default or impair any
right consequent thereon.

         SECTION 2.7. Event of Default; Notice.

         (a) The Guarantee Trustee shall, within 30 days after the occurrence of
an Event of Default known to it, transmit by mail,  first class postage prepaid,
to the  Holders,  notice of any such  Event of  Default,  unless  such  Event of
Default has been cured before the giving of such notice,  provided that,  except
in the case of a default in the payment of a Guarantee  Payment,  the  Guarantee
Trustee  shall be  protected  in  withholding  such notice if and so long as the
board of directors,  the executive  committee or a trust  committee of directors
and/or  Responsible  Officers of the Guarantee  Trustee in good faith determines
that the withholding of such notice is in the interests of the Holders.

         (b) The Guarantee  Trustee shall not be deemed to have knowledge of any
Event of Default  unless the  Guarantee  Trustee  shall  have  received  written
notice, or a Responsible Officer

                                       -6-






charged with the administration of this Guarantee  Agreement shall have obtained
actual knowledge, of such Event of Default.

         SECTION 2.8. Conflicting Interests.

         The  Trust   Agreement  and  the  Indenture   shall  be  deemed  to  be
specifically  described in this  Guarantee  Agreement for the purposes of clause
(i) of the first proviso contained in Section 310(b) of the Trust Indenture Act.


                                   ARTICLE III

               POWERS, DUTIES AND RIGHTS OF THE GUARANTEE TRUSTEE

         SECTION 3.1. Powers and Duties of the Guarantee Trustee.

         (a) This Guarantee Agreement shall be held by the Guarantee Trustee for
the benefit of the Holders,  and the  Guarantee  Trustee shall not transfer this
Guarantee  Agreement to any Person  except to a Successor  Guarantee  Trustee on
acceptance by such  Successor  Guarantee  Trustee of its  appointment  to act as
Guarantee  Trustee  hereunder.  The right,  title and interest of the  Guarantee
Trustee, as such,  hereunder shall automatically vest in any Successor Guarantee
Trustee,  upon acceptance by such Successor Guarantee Trustee of its appointment
hereunder, and such vesting and cessation of title shall be effective whether or
not  conveyancing  documents  have been executed and  delivered  pursuant to the
appointment of such Successor Guarantee Trustee.

         (b)  If an  Event  of  Default  has  occurred  and is  continuing,  the
Guarantee Trustee shall enforce this Guarantee  Agreement for the benefit of the
Holders.

         (c) The  Guarantee  Trustee,  before  the  occurrence  of any  Event of
Default  and after the curing of all Events of Default  that may have  occurred,
shall  undertake  to perform only such duties as are  specifically  set forth in
this  Guarantee  Agreement  (including  pursuant to Section 2.1), and no implied
covenants  shall be read into this  Guarantee  Agreement  against the  Guarantee
Trustee.  If an Event of Default has occurred (that has not been cured or waived
pursuant to Section  2.6),  the  Guarantee  Trustee  shall  exercise such of the
rights and powers  vested in it by this  Guarantee  Agreement,  and use the same
degree of care and skill in its  exercise  thereof,  as a prudent  person  would
exercise  or use  under  the  circumstances  in the  conduct  of his or her  own
affairs.

         (d) No  provision  of this  Guarantee  Agreement  shall be construed to
relieve the Guarantee Trustee from liability for its own negligent  action,  its
own negligent failure to act or its own wilful misconduct, except that:


                                       -7-






                  (i) Prior to the  occurrence of any Event of Default and after
         the  curing or  waiving  of all such  Events of  Default  that may have
         occurred:

                           (A)  the  duties  and  obligations  of the  Guarantee
                  Trustee shall be determined  solely by the express  provisions
                  of this  Guarantee  Agreement  (including  pursuant to Section
                  2.1), and the Guarantee Trustee shall not be liable except for
                  the   performance  of  such  duties  and  obligations  as  are
                  specifically set forth in this Guarantee Agreement  (including
                  pursuant to Section 2.1); and

                           (B) in the  absence  of bad  faith on the part of the
                  Guarantee  Trustee,  the  Guarantee  Trustee may  conclusively
                  rely, as to the truth of the statements and the correctness of
                  the  opinions  expressed  therein,  upon any  certificates  or
                  opinions  furnished to the Guarantee Trustee and conforming to
                  the requirements of this Guarantee Agreement;  but in the case
                  of any such  certificates  or opinions  that by any  provision
                  hereof or of the Trust Indenture Act are specifically required
                  to be  furnished  to  the  Guarantee  Trustee,  the  Guarantee
                  Trustee shall be under a duty to examine the same to determine
                  whether  or not  they  conform  to the  requirements  of  this
                  Guarantee Agreement.

                  (ii) The  Guarantee  Trustee shall not be liable for any error
         of  judgment  made  in  good  faith  by a  Responsible  Officer  of the
         Guarantee Trustee, unless it shall be proved that the Guarantee Trustee
         was  negligent  in  ascertaining  the  pertinent  facts upon which such
         judgment was made.

                  (iii) The  Guarantee  Trustee shall not be liable with respect
         to any  action  taken or  omitted  to be  taken by it in good  faith in
         accordance  with  the  direction  of the  Holders  of not  less  than a
         Majority in Liquidation  Amount of the Capital  Securities  relating to
         the time,  method and place of conducting any proceeding for any remedy
         available to the Guarantee  Trustee,  or exercising  any trust or power
         conferred upon the Guarantee Trustee, under this Guarantee Agreement.

                  (iv)  Subject to Sections  3.1(b) and 3.1(d),  no provision of
         this Guarantee  Agreement shall require the Guarantee Trustee to expend
         or risk its own funds or otherwise incur personal  financial  liability
         in the  performance  of any of its duties or in the  exercise of any of
         its rights or powers,  if the Guarantee  Trustee shall have  reasonable
         grounds for believing  that the repayment of such funds or liability is
         not  reasonably  assured  to it  under  the  terms  of  this  Guarantee
         Agreement or adequate  indemnity  against such risk or liability is not
         reasonably assured to it.

         SECTION 3.2. Certain Rights of Guarantee Trustee.

         (a) Subject to the provisions of Section 3.1:


                                       -8-






                  (i)  The  Guarantee  Trustee  may  rely  and  shall  be  fully
         protected  in acting or  refraining  from acting  upon any  resolution,
         certificate,  statement,  instrument, opinion, report, notice, request,
         direction,  consent,  order, bond,  debenture,  note, other evidence of
         indebtedness or other paper or document reasonably believed by it to be
         genuine and to have been signed,  sent or presented by the proper party
         or parties.

                  (ii) Any  direction or act of the  Guarantor  contemplated  by
         this  Guarantee  Agreement  shall  be  sufficiently   evidenced  by  an
         Officers' Certificate unless otherwise prescribed herein.

                  (iii)  Whenever,  in  the  administration  of  this  Guarantee
         Agreement,  the Guarantee Trustee shall deem it desirable that a matter
         be proved or established  before taking,  suffering or omitting to take
         any action  hereunder,  the Guarantee Trustee (unless other evidence is
         herein specifically prescribed) may, in the absence of bad faith on its
         part,  request  and rely  upon an  Officers'  Certificate  which,  upon
         receipt of such request from the Guarantee  Trustee,  shall be promptly
         delivered by the Guarantor.

                  (iv) The Guarantee Trustee may consult with legal counsel, and
         the written  advice or opinion of such legal  counsel  with  respect to
         legal matters shall be full and complete  authorization  and protection
         in respect of any action  taken,  suffered or omitted to be taken by it
         hereunder in good faith and in accordance  with such advice or opinion.
         Such legal  counsel may be legal counsel to the Guarantor or any of its
         Affiliates  and may be one of its or  their  employees.  The  Guarantee
         Trustee  shall  have  the  right  at  any  time  to  seek  instructions
         concerning  the  administration  of this  Guarantee  Agreement from any
         court of competent jurisdiction.

                  (v) The  Guarantee  Trustee  shall be under no  obligation  to
         exercise  any of the  rights or powers  vested in it by this  Guarantee
         Agreement at the request or direction of any Holder  unless such Holder
         shall have provided to the Guarantee Trustee such adequate security and
         indemnity as would  satisfy a reasonable  person in the position of the
         Guarantee  Trustee against the costs,  expenses  (including  attorneys'
         fees and  expenses)  and  liabilities  that might be  incurred by it in
         complying  with such request or direction,  including  such  reasonable
         advances as may be requested by the  Guarantee  Trustee;  provided that
         nothing  contained in this Section  3.2(a)(v) shall be taken to relieve
         the Guarantee Trustee,  upon the occurrence of an Event of Default,  of
         its  obligation  to exercise the rights and powers vested in it by this
         Guarantee Agreement.

                  (vi)  The  Guarantee  Trustee  shall  not be bound to make any
         investigation  into the  facts or  matters  stated  in any  resolution,
         certificate,  statement,  instrument, opinion, report, notice, request,
         direction,  consent,  order, bond,  debenture,  note, other evidence of
         indebtedness or other paper or document,  but the Guarantee Trustee, in
         its  discretion,  may make such further inquiry or  investigation  into
         such facts or matters as it may see fit.


                                       -9-






                  (vii) The  Guarantee  Trustee may execute any of the trusts or
         powers  hereunder or perform any duties hereunder either directly or by
         or through its agents or attorneys, and the Guarantee Trustee shall not
         be responsible for any misconduct or negligence on the part of any such
         agent or attorney appointed by it with due care hereunder.

                  (viii)  Whenever  in  the  administration  of  this  Guarantee
         Agreement  the  Guarantee  Trustee  shall deem it  desirable to receive
         instructions  with respect to  enforcing  any remedy or right or taking
         any other  action  hereunder,  the  Guarantee  Trustee  (A) may request
         instructions  from the  Holders,  (B) may refrain from  enforcing  such
         remedy or right or taking such other action until such instructions are
         received,  and (C) shall be protected in acting in accordance with such
         instructions.

         (b) No provision of this Guarantee  Agreement shall be deemed to impose
any duty or obligation  on the  Guarantee  Trustee to perform any act or acts or
exercise any right, power, duty or obligation  conferred or imposed on it in any
jurisdiction  in which it shall be illegal,  or in which the  Guarantee  Trustee
shall be  unqualified  or  incompetent  in accordance  with  applicable  law, to
perform  any such act or acts or to  exercise  any such  right,  power,  duty or
obligation.  No permissive power or authority available to the Guarantee Trustee
shall  be  construed  to be a duty to act in  accordance  with  such  power  and
authority.

         SECTION 3.3. Compensation; Fees.

         The Guarantor agrees:

                  (a) to pay to the  Guarantee  Trustee  from  time to time such
         reasonable  compensation  for all services  rendered by it hereunder as
         may be agreed by the Guarantor  and the Guarantee  Trustee from time to
         time (which  compensation  shall not be limited by any provision of law
         in regard to the compensation of a trustee of an express trust); and

                  (b)  except  as  otherwise   expressly   provided  herein,  to
         reimburse  the  Guarantee  Trustee  upon  request  for  all  reasonable
         expenses,  disbursements and advances incurred or made by the Guarantee
         Trustee in accordance  with any provision of this  Guarantee  Agreement
         (including   the   reasonable   compensation   and  the   expenses  and
         disbursements  of its agents  and  counsel),  except any such  expense,
         disbursement or advance as may be attributable to its negligence or bad
         faith; and

                  (c) to the fullest  extent  permitted  by  applicable  law, to
         indemnify  and  hold  harmless  (i) the  Guarantee  Trustee,  (ii)  any
         Affiliate of the Guarantee  Trustee,  and (iii) any officer,  director,
         shareholder, employee, representative or agent of the Guarantee Trustee
         (referred to herein as an "Indemnified  Person"),  from and a any loss,
         damage, liability, tax, penalty, expense or claim of any kind or nature
         whatsoever  incurred by such Indemnified Person in connection with this
         Guarantee Agreement or any act or omission performed or omitted by such
         Indemnified Person in good faith and in manner

                                      -10-






         such Indemnified  Person reasonably  believed to be within the scope of
         authority  conferred  on such  Indemnified  Person  by  this  Guarantee
         Agreement,  except that no  Indemnified  Person shall be entitled to be
         indemnified  in respect of any loss,  damage or claim  incurred by such
         Indemnified  Person by reason of negligence or willful  misconduct with
         respect to such acts or omissions.

         The Guarantee Trustee will not claim or exact any lien or charge on any
Guarantee  Payments  as a result of any amount  due to it under  this  Guarantee
Agreement.

         The  provisions  of this Section 3.3 shall survive the  termination  of
this Guarantee Agreement or the resignation or removal of the Guarantee Trustee.


                                   ARTICLE IV

                                GUARANTEE TRUSTEE

         SECTION 4.1. Guarantee Trustee; Eligibility.

         (a) There shall at all times be a Guarantee Trustee which shall:

                  (i) not be an Affiliate of the Guarantor; and

                  (ii) be a Person  that is a national or state  chartered  bank
         and eligible  pursuant to the Trust  Indenture Act to act as such,  and
         that has at the time of such appointment securities rated in one of the
         three highest rating categories by a nationally recognized  statistical
         rating  organization  and a combined  capital  and  surplus of at least
         $50,000,000,  and shall be a corporation  meeting the  requirements  of
         Section  310(a)  of  the  Trust  Indenture  Act.  If  such  corporation
         publishes reports of condition at least annually, pursuant to law or to
         the requirements of its supervising or examining  authority,  then, for
         the  purposes of this  Section 4.1 and to the extent  permitted  by the
         Trust  Indenture  Act,  the  combined   capital  and  surplus  of  such
         corporation  shall be deemed to be its combined  capital and surplus as
         set forth in its most recent report of condition so published.

         (b) If at any time the Guarantee  Trustee shall cease to be eligible to
so act under Section 4.1(a),  the Guarantee Trustee shall immediately  resign in
the manner and with the effect set out in Section 4.2.

         (c) If the  Guarantee  Trustee has or shall  acquire  any  "conflicting
interest"  within the meaning of Section 310(b) of the Trust  Indenture Act, the
Guarantee Trustee and Guarantor shall in all respects comply with the provisions
of Section 310(b) of the Trust Indenture Act.


                                      -11-






     SECTION 4.2. Appointment, Removal and Resignation of the Guarantee Trustee.

         (a) Subject to Section 4.2(c),  the Guarantee  Trustee may be appointed
or removed at any time by the Guarantor.

         (b) Subject to Section  4.2(c),  the Guarantee  Trustee may resign from
office  (without  need for prior or  subsequent  accounting)  by giving  written
notice  thereof to the Holders and the  Guarantor  and by appointing a successor
Guarantee Trustee.

         (c) The Guarantee Trustee appointed hereunder shall hold office until a
Successor  Guarantee  Trustee shall have been  appointed and shall have accepted
such  appointment.  No removal or  resignation  of a Guarantee  Trustee shall be
effective  until a  Successor  Guarantee  Trustee  has  been  appointed  and has
accepted  such  appointment  by written  instrument  executed by such  Successor
Guarantee  Trustee  and  delivered  to the  Guarantor  and,  in the  case of any
resignation, the resigning Guarantee Trustee.

         (d) If the  Guarantee  Trustee  shall  resign,  be  removed  or  become
incapable  of  acting  as  Guarantee  Trustee  and a  replacement  shall  not be
appointed prior to such  resignation or removal,  or if a vacancy shall occur in
the office of  Guarantee  Trustee for any  reason,  and no  Successor  Guarantee
Trustee shall have been  appointed and accepted  appointment as provided in this
Section 4.2 within 60 days after  delivery to the Holders and the Guarantor of a
notice of  resignation,  the resigning  Guarantee  Trustee may petition,  at the
expense of the Guarantor, any court of competent jurisdiction for appointment of
a Successor Guarantee Trustee. Such court may thereupon,  after prescribing such
notice, if any, as it may deem proper, appoint a Successor Guarantee Trustee.


                                    ARTICLE V

                                    GUARANTEE

         SECTION 5.1. Guarantee.

         The Guarantor irrevocably and unconditionally  agrees to pay in full to
the Holders the Guarantee Payments (without  duplication of amounts  theretofore
paid by or on behalf of the Issuer  Trust),  as and when due,  regardless of any
defense,  right of set-off  or  counterclaim  that the Issuer  Trust may have or
assert,  except the defense of payment.  The  Guarantor's  obligation  to make a
Guarantee  Payment may be satisfied by direct payment of the required amounts by
the  Guarantor to the Holders or by causing the Issuer Trust to pay such amounts
to the Holders.

         SECTION 5.2. Waiver of Notice and Demand.

         The Guarantor  hereby  waives  notice of  acceptance of this  Guarantee
Agreement  and of any  liability to which it applies or may apply,  presentment,
demand for payment, any right to

                                      -12-






require a proceeding  first against the Guarantee  Trustee,  the Issuer Trust or
any other Person before  proceeding  against the Guarantor,  protest,  notice of
nonpayment,  notice of dishonor,  notice of redemption and all other notices and
demands.

         SECTION 5.3. Obligations Not Affected.

         The  obligations,  covenants,  agreements  and duties of the  Guarantor
under this Guarantee Agreement shall in no way be affected or impaired by reason
of the happening from time to time of any of the following:

                  (a) the release or waiver,  by  operation  of law or otherwise
         (other than by Act (as defined in the Trust Agreement) of the Holders),
         of the  performance or observance by the Issuer Trust of any express or
         implied agreement,  covenant, term or condition relating to the Capital
         Securities to be performed or observed by the Issuer Trust;

                  (b) the  extension of time for the payment by the Issuer Trust
         of all or any portion of the Distributions  (other than an extension of
         time for payment of  Distributions  that results from the  extension of
         any  interest  payment  period on the  Debentures  as  provided  in the
         Indenture),  Redemption  Price,  Liquidation  Distribution or any other
         sums payable under the terms of the Capital Securities or the extension
         of time for the performance of any other obligation under,  arising out
         of, or in connection with, the Capital Securities;

                  (c) any failure,  omission,  delay or lack of diligence on the
         part  of  the  Holders  to  enforce,  assert  or  exercise  any  right,
         privilege,  power or remedy  conferred  on the Holders  pursuant to the
         terms  of the  Capital  Securities,  or any  action  on the part of the
         Issuer Trust granting indulgence or extension of any kind;

                  (d) the  voluntary or  involuntary  liquidation,  dissolution,
         receivership,  insolvency,  bankruptcy,  assignment  for the benefit of
         creditors, reorganization,  arrangement, composition or readjustment of
         debt of, or other similar  proceedings  affecting,  the Issuer Trust or
         any of the assets of the Issuer Trust;

               (e) any  invalidity  of, or defect or deficiency  in, the Capital
          Securities;

                  (f) the settlement or compromise of any obligation  guaranteed
         hereby or hereby incurred; or

                  (g) any other  circumstance  whatsoever  that might  otherwise
         constitute  a legal or  equitable  discharge  or defense of a guarantor
         (other than payment of the underlying obligation),  it being the intent
         of this Section 5.3 that the  obligations  of the  Guarantor  hereunder
         shall be absolute and unconditional under any and all circumstances.

There  shall be no  obligation  of the  Holders to give notice to, or obtain the
consent of, the Guarantor with respect to the happening of any of the foregoing.

                                      -13-







         SECTION 5.4. Rights of Holders.

         The Guarantor expressly acknowledges that: (i) this Guarantee Agreement
will be deposited  with the Guarantee  Trustee to be held for the benefit of the
Holders;  (ii) the  Guarantee  Trustee has the right to enforce  this  Guarantee
Agreement  on  behalf  of the  Holders;  (iii)  the  Holders  of a  Majority  in
Liquidation  Amount of the Capital Securities have the right to direct the time,
method and place of conducting any  proceeding  for any remedy  available to the
Guarantee Trustee in respect of this Guarantee Agreement or exercising any trust
or power  conferred upon the Guarantee  Trustee under this Guarantee  Agreement;
and (iv) any  Holder may  institute  a legal  proceeding  directly  against  the
Guarantor to enforce its rights under this  Guarantee  Agreement  without  first
instituting a legal proceeding against the Guarantee  Trustee,  the Issuer Trust
or any other Person.

         SECTION 5.5. Guarantee of Payment.

         This  Guarantee  Agreement  creates a  guarantee  of payment and not of
collection. This Guarantee Agreement will not be discharged except by payment of
the Guarantee Payments in full (without  duplication of amounts theretofore paid
by the  Issuer  Trust) or upon the  distribution  of  Debentures  to  Holders as
provided in the Trust Agreement.

         SECTION 5.6. Subrogation.

         The Guarantor shall be subrogated to all rights (if any) of the Holders
against the Issuer  Trust in respect of any  amounts  paid to the Holders by the
Guarantor under this Guarantee Agreement;  provided, however, that the Guarantor
shall not (except to the extent  required  by  mandatory  provisions  of law) be
entitled  to  enforce or  exercise  any  rights  which it may  acquire by way of
subrogation or any indemnity,  reimbursement or other agreement, in all cases as
a result of payment under this Guarantee Agreement,  if, at the time of any such
payment, any amounts are due and unpaid under this Guarantee  Agreement.  If any
amount shall be paid to the  Guarantor in violation of the  preceding  sentence,
the  Guarantor  agrees to hold such  amount in trust for the  Holders and to pay
over such amount to the Holders.

         SECTION 5.7. Independent Obligations.

         The  Guarantor   acknowledges   that  its  obligations   hereunder  are
independent  of the  obligations of the Issuer Trust with respect to the Capital
Securities  and that the  Guarantor  shall be liable as principal  and as debtor
hereunder to make  Guarantee  Payments  pursuant to the terms of this  Guarantee
Agreement notwithstanding the occurrence of any event referred to in subsections
(a) through (f), inclusive, of Section 5.3 hereof.

                                      -14-








                                   ARTICLE VI

                           COVENANTS AND SUBORDINATION

         SECTION 6.1. Subordination.

         The  obligations of the Guarantor  under this Guarantee  Agreement will
constitute unsecured  obligations of the Guarantor and will rank subordinate and
junior  in right of  payment  to all  Senior  Indebtedness  (as  defined  in the
Indenture)  of the  Guarantor  to the  extent and in the manner set forth in the
Indenture with respect to the  Debentures,  and the provisions of Article XII of
the Indenture will apply, mutatis mutandis,  to the obligations of the Guarantor
hereunder.  The obligations of the Guarantor  hereunder do not constitute Senior
Indebtedness (as defined in the Indenture) of the Guarantor.

         SECTION 6.2. Pari Passu Guarantees.

         The obligations of the Guarantor  under this Guarantee  Agreement shall
rank pari passu with the  obligations  of the  Guarantor  under (i) any  similar
guarantee  agreements  issued  by the  Guarantor  on behalf  of the  holders  of
preferred  or capital  securities  issued by any Issuer Trust (as defined in the
Indenture);  (ii) the Indenture and the Securities (as defined  therein)  issued
thereunder;  and (iii) any  other  security,  guarantee  or other  agreement  or
obligation  that is expressly  stated to rank pari passu with the obligations of
the Guarantor  under this Guarantee  Agreement or with any obligation that ranks
pari passu with the obligations of the Guarantor under this Guarantee Agreement.


                                   ARTICLE VII

                                   TERMINATION

         SECTION 7.1. Termination.

         This Guarantee Agreement shall terminate and be of no further force and
effect upon (i) full  payment of the  Redemption  Price (as defined in the Trust
Agreement) of all Capital Securities, (ii) the distribution of Debentures to the
Holders in exchange for all of the Capital Securities, (iii) full payment of the
amounts  payable  in  accordance  with  Article IX of the Trust  Agreement  upon
liquidation  of the Issuer  Trust or (iv) the  distribution  of the  Guarantor's
common stock to the Holders in respect of the  conversion  of all of the Capital
Securities into the  Guarantor's  common stock.  Notwithstanding  the foregoing,
this Guarantee Agreement will continue to be effective or will be reinstated, as
the case may be, if at any time any  Holder is  required  to repay any sums paid
with respect to Capital Securities or this Guarantee Agreement.



                                      -15-






                                  ARTICLE VIII

                                  MISCELLANEOUS

         SECTION 8.1. Successors and Assigns.

         All  guarantees and  agreements  contained in this Guarantee  Agreement
shall bind the successors,  assigns, receivers,  trustees and representatives of
the  Guarantor  and shall  inure to the  benefit of the  Holders of the  Capital
Securities then outstanding.  Except in connection with a consolidation,  merger
or sale  involving  the  Guarantor  that is permitted  under Article VIII of the
Indenture and pursuant to which the  successor or assignee  agrees in writing to
perform the Guarantor's  obligations  hereunder,  the Guarantor shall not assign
its obligations hereunder, and any purported assignment other than in accordance
with this provision shall be void.

         SECTION 8.2. Amendments.

         Except with  respect to any changes  that do not  adversely  affect the
rights of the Holders in any  material  respect (in which case no consent of the
Holders will be required), this Guarantee Agreement may only be amended with the
prior approval of the Holders of not less than a Majority in Liquidation  Amount
of the Capital  Securities.  The provisions of Article VI of the Trust Agreement
concerning meetings of the Holders shall apply to the giving of such approval.

         SECTION 8.3. Notices.

         (a) Any notice, request or other communication required or permitted to
be given  hereunder  shall be in writing,  duly signed by the party  giving such
notice, and delivered, by facsimile or first class mail as follows:

         (i) if given to the Guarantor,  to the address or facsimile  number set
forth below or such other address or facsimile  number as the Guarantor may give
notice to the Guarantee Trustee and the Holders:

                  HSB Group, Inc.
                  One State Street
                  Hartford, Connecticut  06102
                  General Counsel
                  Facsimile: (860) 722-1818

         (ii) if given to the  Guarantee  Trustee,  at the address or  facsimile
number  set  forth  below or such  other  address  or  facsimile  number  as the
Guarantee Trustee may give notice to the Guarantor and the Holders:


                                      -16-






                  The First National Bank of Chicago
                  One First National Plaza, Suite #0126
                  Chicago, Illinois  60070-0126
                  Corporate Trust Division
                  Facsimile:  (312) 407-1708

         (iii) if given to any Holder,  in the manner set forth in Section  10.8
of the Trust Agreement.

         (b) All  notices  hereunder  shall be deemed to have  been  given  when
received in person,  by  facsimile  with receipt  confirmed,  or mailed by first
class  mail,  postage  prepaid,  except  that if a notice or other  document  is
refused delivery or cannot be delivered because of a changed address of which no
notice was given,  such  notice or other  document  shall be deemed to have been
delivered on the date of such refusal or inability to deliver, provided that any
notice  given as  provided in Section  8.3(a)(iii)  shall be deemed to have been
given at the time specified in Section 10.8 of the Trust Agreement.


         SECTION 8.4. Benefit.

         This  Guarantee  Agreement is solely for the benefit of the Holders and
is not separately transferable from the Capital Securities.

         SECTION 8.5. Governing Law.

         THIS  GUARANTEE  AGREEMENT  SHALL  BE  GOVERNED  BY  AND  CONSTRUED  IN
ACCORDANCE  WITH  THE LAWS OF THE  STATE  OF NEW  YORK,  WITHOUT  REGARD  TO THE
PRINCIPLES OF CONFLICTS OF LAWS.

         SECTION 8.6. Counterparts.

         This Guarantee Agreement may be executed in any number of counterparts,
each of which  so  executed  shall be  deemed  to be an  original,  but all such
counterparts shall together constitute but one and the same instrument.

                                      -17-





         IN WITNESS  WHEREOF,  the parties  hereto  have  caused this  Guarantee
Agreement  to be duly  executed,  and  their  respective  corporate  seals to be
hereunto affixed, all as of the day and year first above written.


                              HSB GROUP, INC.


                                  By:     /s/ Saul L. Basch
                                  Name:       Saul L. Basch
                                  Title:      Senior Vice President, Treasurer
                                              and Chief Financial Officer


                              THE FIRST NATIONAL BANK OF CHICAGO,
                              as Guarantee Trustee


                                  By:        /s/ Melissa G. Weisman
                                  Name:      Melissa G. Weisman
                                  Title:     Vice President

0151329.03-01S7a