STOCKHOLDER  AGREEMENT  dated as of December 1, 1998 between X.L.  America,
Inc.  ("Emerald"),  and the  undersigned  holder of shares of common stock,  par
value  $1.00 per share  (the  "Common  Stock"),  of  Intercargo  Corporation,  a
Delaware corporation (the "Company") for and on behalf of itself and each of its
affiliates  which is a holder of  Common  Stock  (the  undersigned  holder,  the
"Stockholder"   and,  where  the  content  requires,   all  such  holders,   the
"Stockholders" or each A "Stockholder").

     WHEREAS,  Emerald and the Company  propose to enter into an  Agreement  and
Plan of  Merger  dated as of the date  hereof  (as the  same may be  amended  or
supplemented,  the "Merger  Agreement";  capitalized  terms used but not defined
herein shall have the meanings set forth in the Merger Agreement)  providing for
the merger of the Company with and into Emerald (the  "Merger"),  upon the terms
and subject to the conditions set forth in the Merger Agreement;

     WHEREAS,  each  Stockholder  owns the number of shares of Common  Stock set
forth opposite its name on the signature page of this Agreement  (such shares of
Common  Stock,  the  "Existing  Shares" and,  together  with any other shares of
capital stock of the Company acquired by such Stockholder  after the date hereof
and during the term of this Agreement,  being collectively referred to herein as
the "Subject Shares"); and

     WHEREAS,  as a  condition  to its  willingness  to enter  into  the  Merger
Agreement, Emerald has requested that Stockholder enter into this Agreement;

     NOW, THEREFORE,  in consideration of the premises and the  representations,
warranties and agreements contained herein, the parties agree as follows:

     1.  Representations  and Warranties of the Stockholder.  Stockholder hereby
represents and warrants to Emerald as of the date hereof as follows:

     (a) Stockholder  has all requisite  legal capacity,  power and authority to
enter  into this  Agreement  and to  consummate  the  transactions  contemplated
hereby.  This Agreement has been duly authorized,  executed and delivered by the
Stockholder  and  constitutes a valid and binding  obligation of the Stockholder
enforceable  in  accordance  with its terms.  The execution and delivery of this
Agreement do not, and the consummation of the transactions  contemplated  hereby
and compliance  with the terms hereof will not,  conflict with, or result in any
breach or violation of, or default  (with or without  notice or lapse of time or
both) under any provision of, any Stockholder's charter or by-laws. The Existing
Shares are not subject to any lien, pledge or encumbrance of any kind other than
the  Stockholder's  Agreement  with the  Company  with  respect to the  Existing
Shares. <PAGE>

     (b)  Stockholder is the record holder or beneficial  owner of the number of
the Existing  Shares as is set forth on the signature  page hereto.  On the date
hereof,  the Existing  Shares set forth on the signature page hereto  constitute
all of the outstanding shares of Common Stock owned of record or beneficially by
Stockholder.  Stockholder  does not have record or  beneficial  ownership of any
shares of Common Stock not set forth on the signature page hereto.  Stockholders
have,  collectively,  sole  power  of  disposition  with  respect  to all of the
Existing  Shares set forth on the  signature  page hereto and sole voting  power
with  respect  to the  matters  set forth in  Section 3 hereof and sole power to
demand  dissenter's or appraisal rights, in each case with respect to all of the
Existing Shares set forth on the signature page hereto,  with no restrictions on
such rights, subject to applicable insurance laws and regulations in the case of
Subject Shares owned of record by an insurance subsidiary stockholder and to the
terms of this Agreement.

     (c)  Stockholder's  Shares and the certificates  representing  such Subject
Shares  are  now  and at all  times  during  the  term  hereof  will  be held by
Stockholder,  or by a nominee or custodian for the benefit of Stockholder,  free
and clear of all liens, claims,  security interests,  proxies,  voting trusts or
agreements, understandings or arrangements or any other encumbrances whatsoever,
except for any such encumbrances or proxies arising hereunder.

     2. Representations and Warranties of Emerald. Emerald hereby represents and
warrants to  Stockholder  that  Emerald has all  requisite  corporate  power and
authority  to enter  into this  Agreement  and to  consummate  the  transactions
contemplated  hereby.  The execution and delivery of this  Agreement by Emerald,
and the consummation of the  transactions  contemplated  hereby,  have been duly
authorized  by all  necessary  corporation  action on the part of Emerald.  This
Agreement   has  been  duly   --------------------------------------------------
executed and delivered by Emerald and constitutes a valid and binding obligation
of Emerald enforceable in accordance with its terms.

     3. Covenants of  Stockholder.  From and after the date hereof and until the
termination of this Agreement in accordance with Section 6,  Stockholder  agrees
as follows: ---------------------------------

     (a) At any meeting of  stockholders  of the Company called to vote upon the
Merger  or the  Merger  Agreement  or any  adjournment  thereof  or in any other
circumstances  upon which a vote,  consent or other approval with respect to the
Merger or the Merger Agreement is sought, Stockholder shall vote (or cause to be
voted) the Subject Shares in favor of the Merger, the adoption by the Company of
the Merger Agreement and the approval of the terms thereof.

     (b) At any meeting of  stockholders  of the  Company or at any  adjournment
thereof or in any other circumstances upon which the Stockholder's vote, consent
or other approval is sought,  the Stockholder  shall vote (or cause to be voted)
<PAGE>

the Subject  Shares  against (i) any merger  agreement or merger (other than the
Merger Agreement and the Merger),  consolidation,  combination,  sale of assets,
reorganization,  recapitalization,  dissolution, liquidation or winding-up of or
by  the  Company  or  any  other  takeover  proposal  (collectively,   "Takeover
Proposal"),  (ii) any action or  agreement  that would result in a breach of any
covenant, representation or warranty or any other obligation or agreement of the
Company under the Merger  Agreement or this  Agreement or (iii) (x) any material
amendment of the Company's  certificate  of  incorporation  or by-laws,  (y) any
change in a majority of the persons who constitute the Board of Directors of the
Company or (z) any other proposal or transaction involving the Company, which is
intended by Stockholder to, or which Emerald  notifies  Stockholder that Emerald
reasonably believes will, impede,  frustrate,  prevent, delay or nullify (A) the
ability of the Company to consummate  the Merger or (B) any of the  transactions
contemplated by this Agreement or the Merger Agreement.

     (c) Stockholder agrees not to (i) offer to sell, sell, transfer,  encumber,
pledge,  assign or  otherwise  dispose  of  (including  by gift)  (collectively,
"Transfer"),  or enter  into any  contract,  option  or other  arrangement  with
respect to or consent to the  Transfer  of, the Subject  Shares or any  interest
therein  to any person  other than  pursuant  to the terms of the  Merger,  (ii)
except as  contemplated  hereby,  grant any proxies or powers of  attorney  with
respect to the Subject Shares, deposit any Subject Shares into a voting trust or
enter into any voting  arrangement  with respect to the Subject  Shares,  or any
interest in the foregoing, except with Emerald, (iii) take any action that would
make any  representation  or warranty of Stockholder  contained herein untrue or
incorrect to have the effect of  preventing or disabling  the  Stockholder  from
performing  Stockholder's  obligations  under this  Agreement  or (iv) commit or
agree to take any of the  foregoing  actions;  provided,  however,  that,  for a
period  equal  to the  shorter  of (A) 360  days  after  Stockholder  elects  to
terminate  this  Agreement  pursuant  to Section  3(f) or (B) the payment by the
Company to Emerald of the Termination Fee,  Stockholder may transfer the Subject
Shares  to the  proponent  of a  Superior  Proposal  upon  the  same  terms  and
conditions  and at the same time as available to all other  shareholders  of the
Company.

     (d) Stockholder hereby irrevocably waives any rights of appraisal or rights
to dissent from the Merger that the Stockholder may have.

     (e) Stockholder agrees with, and covenants to, Emerald that the Stockholder
shall  not  request  that the  Company  register  the  transfer  (book-entry  or
otherwise) of any certificate or uncertificated interest representing any of the
Subject Shares, unless such transfer is made in compliance with this Agreement.

     (f)  Stockholder  will  immediately  cease and cause to be  terminated  any
existing  activities,  discussions or  negotiations  with any parties  conducted
heretofore with respect to the sale, voting or other disposition of the Existing
<PAGE>

Shares or a business combination transaction involving the Company.  Stockholder
shall not  directly or  indirectly,  through any  officer,  director,  employee,
representative,  agent or other person,  solicit or encourage the  initiation or
submission of any direct or indirect  inquiries,  proposals or offers  regarding
any acquisition, merger, takeover bid or sale of all or any of the assets or any
shares of capital stock of the Company, whether or not in writing and whether or
not  delivered to the Company or to the  stockholders  of the Company  generally
(including,  without  limitation,  by way of a tender  offer) by any party other
than  Emerald or its  affiliates  (any of the  foregoing  inquiries or proposals
being referred to herein as an "Acquisition  Proposal") provided,  however, that
nothing  contained  in this  Agreement  shall  prevent the Board of Directors of
Stockholder  from  referring  any  third  party to this  Section  3(f).  Nothing
contained in this Section 3(f) or any other  provision of this  Agreement  shall
prevent the Board of Directors of Stockholder from considering or negotiating an
unsolicited  bona  fide  Acquisition  Proposal.  If the  Board of  Directors  of
Stockholders,  after duly considering  written advice of counsel to Stockholder,
determines  in good  faith  that it would be  likely  to be a  violation  of its
fiduciary   responsibilities   (assuming  such  fiduciary   responsibilities  of
Stockholder's  Board of Directors  vis-a-vis the shareholders of Stockholder are
those of the Board of Directors of the Company vis-a-vis the shareholders of the
Company) to not participate in a Superior Proposal (as defined below),  then (i)
the Stockholder  shall not enter into any agreement with respect to the Superior
Proposal and (ii) any other obligation of Stockholder under this Agreement shall
not be  affected,  unless this  Agreement  is  terminated  pursuant to Section 6
hereof prior to or  simultaneously  with the decision of Stockholder's  Board of
Directors to  participate  in such  Superior  Proposal.  As used herein the term
"Superior  Proposal" means an unsolicited bona fide proposal  publicly made by a
third  party to acquire the Company  pursuant to a tender or exchange  offer,  a
merger, a sale of all or any significant portion of its assets or otherwise that
the Stockholder's Board of Directors determines in its good faith judgment to be
a proposal which, if accepted (x) is reasonably likely to be consummated, taking
into account, without limitation, all legal, financial and regulatory aspects of
such  proposal  and person or persons  making such  proposal  and (y) would,  if
consummated, result in a more favorable transaction to the holders of the Common
Stock than the  transaction  contemplated by the Merger  Agreement.  Stockholder
will  immediately  notify  Emerald,  orally  and in  writing,  of any  direct or
indirect  contact related in any way to an Acquisition  Proposal,  including the
identity of the person involved in such contact, or on whose behalf such contact
is made, and the terms and conditions of any proposal made.

     (g) Stockholder  agrees that,  until this Agreement is terminated,  neither
Stockholder nor any of its affiliates will, without the prior written consent of
Emerald:  (i)  acquire,  offer to  acquire,  or agree to  acquire,  directly  or
indirectly,  by  purchase  or  otherwise,  any  voting  securities  or direct or
indirect  rights  to  acquire  any  voting  securities  of  the  Company  or any
subsidiary  thereof, or of any successor to or person in control of the Company,
<PAGE>

or any assets of the Company or any  subsidiary  or  division  thereof or of any
such successor or controlling  person;  (ii) other than as contemplated  hereby,
make, directly or indirectly, any "solicitation" of "proxies" (as such terms are
used in the rules of the Securities and Exchange Commission) to vote, or seek to
advise or  influence  any  person or entity  with  respect to the voting of, any
voting  securities  of the  Company;  (iii)  make any public  announcement  with
respect to, or submit a proposal  for, or offer of (with or without  conditions)
any extraordinary transaction involving the Company or its securities or assets;
and (iv)  form,  join or in any way  participate  in a "group"  (as  defined  in
Section  13  (d)(3) of the  Securities  Exchange  Act of 1934,  as  amended)  in
connection with any of the foregoing.

     (h) THE STOCKHOLDER HEREBY GRANTS TO, AND APPOINTS EMERALD AND ANY DESIGNEE
OF EMERALD,  EACH OF THEM  INDIVIDUALLY,  STOCKHOLDER'S  IRREVOCABLE  (UNTIL THE
TERMINATION OF THIS  AGREEMENT)  PROXY AND  ATTORNEY-IN-FACT  WITH FULL POWER OF
SUBSTITUTION  TO VOTE THE SUBJECT  SHARES OF STOCKHOLDER AS INDICATED IN SECTION
3(A) AND 3(B) ABOVE. THE STOCKHOLDER INTENDS THIS PROXY TO BE IRREVOCABLE (UNTIL
THE  TERMINATION  OF THIS  AGREEMENT) AND COUPLED WITH AN INTEREST AND WILL TAKE
SUCH FURTHER ACTION TO REVOKE AND HEREBY REVOKES ANY PROXY PREVIOUSLY GRANTED BY
STOCKHOLDER WITH RESPECT TO SUCH STOCKHOLDER'S SUBJECT SHARES.

     4. Further Assurances. The Stockholder will, from time to time, execute and
deliver,  or cause to be executed  and  delivered,  such  additional  or further
consents,  documents and other instruments as Emerald may reasonably request for
the purpose of effectively  carrying out the  transactions  contemplated by this
Agreement. ---------------------------

     5. Assignment.  Neither this Agreement nor any of the rights,  interests or
obligations  hereunder shall be assigned by any of the parties without the prior
written consent of the other parties, except that any Stockholder may assign, in
its  sole  discretion,  any  or all of its  rights,  interests  and  obligations
hereunder to any direct or indirect wholly owned subsidiary of such Stockholder;
provided that both such transferor and transferee  shall continue to be bound by
all the provisions  hereof.  Subject to the preceding  sentence,  this Agreement
will be binding upon,  inure to the benefit of and be enforceable by the parties
and their respective successor and assigns.

     6. Termination. This Agreement shall terminate, and no party shall have any
rights or obligations  hereunder and this  Agreement  shall become null and void
and have no further  effect upon the earlier of (a) the Effective  Time, (b) the
date on which the Merger Agreement is terminated pursuant to Section 8.1 thereof
and (c) five (5) business days after Emerald's  receipt of a written notice form
Stockholder  declaring  its  intention to terminate  this  Agreement in order to
participate  in a Superior  Proposal and a certificate  signed by  Stockholder's
Chairman of the Board attesting that the requirements for termination  specified
in Section  3(f) have been  satisfied;  provided,  however,  that a  termination
pursuant to this clause (c) shall not,  for a period equal to the shorter of (A)
360 days following such termination or (B) the payment by the Company to Emerald
of the  Termination  Fee,  relieve  Stockholder  of the duty to sell only in the
manner set forth in the  concluding  proviso of  Section  3(c).  Nothing in this
Section 6 shall relieve any party of liability for breach of this Agreement.
<PAGE>

     7. Costs and Expenses.  All costs and expenses  incurred in connection with
this agreement and the  consummation  of the  transactions  contemplated  hereby
shall be paid by the party incurring such expenses. ---------------------------

     8. General Provisions.

     (a)  Amendments.  This Agreement may not be amended except by an instrument
in writing signed by each of the parties hereto.

     (b)  Notice.  All notices and other  communications  hereunder  shall be in
writing and shall be deemed given if delivered  personally  or sent by overnight
courier  (providing proof of delivery) to Emerald in accordance with Section 9.2
of the Merger  Agreement  and to  Stockholder  at its  address  set forth on the
signature  page of this Agreement (or at such other address for a party as shall
be specified by like notice).

     (c) Interpretation. When a reference is made in this Agreement to Sections,
such  reference  shall  be to a  Section  to  this  Agreement  unless  otherwise
indicated.  The headings  contained in this Agreement are for reference purposes
only and  shall not  affect in any way the  meaning  or  interpretation  of this
Agreement.  Wherever the words "include",  "includes" or "including" are used in
this  Agreement,  they  shall be deemed  to be  followed  by the words  "without
limitation".

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

     (e)   Counterparts.   This  Agreement  may  be  executed  in  one  or  more
counterparts,  all of which shall be considered one and the same agreement,  and
shall become effective when one or more of the counterparts  have been signed by
each of the parties and  delivered to the one party,  it being  understood  that
each party need not sign the same counterpart.

     (f)  Entire  Agreement;  No  Third-Party   Beneficiaries.   This  Agreement
(including the documents and instruments referred to herein) (i) constitutes the
entire  agreement and supersedes all prior agreements and  understandings,  both
written and oral,  among the parties with respect to the subject  matter  hereof
and (ii) is not intended to confer upon any Person other than the parties hereto
any rights or remedies hereunder.

     (g) Governing  Law. This  Agreement  shall be governed by, and construed in
accordance  with, the laws of the State of Delaware  regardless of the laws that
might otherwise govern under applicable principles of conflicts of law thereof.


<PAGE>

     9.  Enforcement.  The parties agree that irreparable  damage would occur in
the event that any of the  provisions  of this  Agreement  were not performed in
accordance  with  their  specific  terms  or  were  otherwise  breached.  It  is
accordingly  agreed that the  parties  shall be  entitled  to an  injunction  or
injunctions to prevent  breaches of this  Agreement and to enforce  specifically
the terms and  provisions  of this  Agreement in any court of the United  States
located in the State of Delaware  or in a Delaware  state  court,  this being in
addition to any other remedy to which they are entitled at law or in equity.  In
addition,  each of the parties  hereto (i)  consents to submit such party to the
personal  jurisdiction  of any Federal court located in the State of Delaware or
any Delaware  state court in the event any dispute  arises out of this Agreement
or any of the transactions contemplated hereby, (ii) agrees that such party will
not  attempt to deny or defeat  such  personal  jurisdiction  by motion or other
request  for leave from any such  court;  (iii)  agrees that such party will not
bring any action  relating to this  Agreement or the  transactions  contemplated
hereby in any court other than a Federal  court sitting in the state of Delaware
or a  Delaware  state  court  and (iv)  waives  any  right to trial by jury with
respect to any claim or proceeding  related to or arising out of this  Agreement
or any of the transactions  contemplated hereby. All rights, powers and remedies
provided under this Agreement or otherwise available in respect hereof at law or
in equity  shall be  cumulative  and not  alternative,  and the  exercise of any
thereof by any party shall not preclude the  simultaneous  or later  exercise of
any other such right, power or remedy by such party.


<PAGE>


     IN WITNESS  WHEREOF,  Emerald has caused this Agreement to be signed by its
officer  thereunto duly  authorized and Stockholder has caused this Agreement to
be signed by its officer  thereunto  duly  authorized,  all as of the date first
written above.


                                                   X.L. AMERICA, INC.


                                                   By:  /s/Paul S. Giordano     
Name:  Paul S. Giordano
                                                   Title: Senior Vice President 
                                                            and General Counsel

Number of Subject Shares: 1,899,223 SECURITY INSURANCE COMPANY OF HARTFORD



                                                   By:  /s/John J. McCann       
                                                   Name:    John J. McCann
                                                   Title:   Executive Vice
                                                   President
                                                   Address: 9 Farm Springs Road
                                                   Farmington, CT  06032







<PAGE>