Aon

                                   SEVERANCE

                                      PLAN



                               Aon Severance Plan


                                    Preamble


       The name of this plan is the Aon Severance Plan (the "Plan"). Its purpose
       is to compensate  staff employees of Aon Corporation and its subsidiaries
       for unavoidable and permanent loss of employment under the  circumstances
       specified  below.  Benefits  are in  consideration  of the  waiver of any
       employment-related  litigation and claims against Aon  Corporation or its
       subsidiaries. The Plan shall be effective as of May 1, 1997, and apply to
       employees  notified of termination of employment by Aon Corporation or by
       a subsidiary  on or after that date.  All prior  existing  severance  pay
       plans,  programs or practices for employees,  whether formal or informal,
       are hereby revoked and terminated.

                                    SECTION 1
                                    ---------

                                   DEFINITIONS
                                   -----------


1.01   "Board" shall mean the board of directors of Aon Corporation.

1.02   "Cause" shall mean:

       (a)    excessive  absenteeism  or tardiness  which violates the Company's
              attendance standards;
       (b)    unsatisfactory job performance;
       (c)    violation of Company policies;
       (d)    breach of fiduciary duty; theft; fraud; dishonesty;  embezzlement;
              violation  of  securities  laws;   violation  of  non-competition,
              nonsolicitation or confidentiality agreements;
       (e)    falsification of employment application or other business records;
       (f)    insubordination   (e.g.,  failure  to  follow  direct  supervisory
              instructions);
       (g)    unethical or criminal conduct.

1.03   "Committee" shall mean the Benefits Committee appointed by the Board. The
       Committee is designated as the plan administrator and named fiduciary.

1.04   "Company" shall mean Aon Corporation and its majority owned subsidiaries.

1.05   "Compensation"  shall mean  solely  salary  and fixed base  compensation.
       Compensation  shall be determined  before  excluding any pretax deferrals
       for retirement,  health,  welfare,  death, insurance, or similar plans of
       the Company. The following are examples of items that are not included in
       Compensation:  (a) net and deferred commission payments; (b) bonuses; (c)
       stock  awards;  (d) expense  reimbursements;  (e) income from exercise of
       stock options; (f) overtime pay; (g) overrides; and (h) car allowances.

                                       - 2 -


1.06   "Employee"  shall mean any regular  United  States staff  employee of the
       Company working 20 or more hours a week. The term,  "Employee"  shall not
       include independent contractors, any individual treated as an independent
       contractor  by the Company  but  considered  an employee by the  Internal
       Revenue  Service or other third party,  leased  employees,  and temporary
       employees.

1.07   "Involuntary  Termination  of Employment"  shall mean any  Termination of
       Employment with the Company due to the following:

              (a)    Elimination  of the Employee's  job,  provided that (i) the
                     Employee  has made a good  faith  effort to secure  another
                     position   within  the  Company;   and  (ii)  there  is  no
                     possibility that another position may be secured within the
                     Company.  A  temporary  or  seasonal  lay-off  shall not be
                     considered an Involuntary Termination of Employment.
              (b)    Divestiture or other disposition of a subsidiary or unit of
                     the Company,  where an Employee of such  subsidiary or unit
                     is  not  employed  by  the  acquiring  company  or  offered
                     employment by the acquiring company.

       An Involuntary  Termination of Employment shall not include,  among other
       events: Resignation; Termination of Employment for Cause; and Termination
       of Employment on account of disability.

1.08   "Participant"  shall mean an Employee eligible for benefits under Section
       2.01.

1.09   "Plan" shall mean the Aon Severance Plan.

1.10   "Release"  shall mean a release of Employee  claims in the form set forth
       in Appendix A.

1.11   "Resignation"  shall mean a  Termination  of  Employment  effected by the
       Employee,  or effected by mutual  agreement  between the Employee and the
       Company.

1.12   "Termination   of   Employment"   shall   mean  the   cessation   of  the
       classification  of an  Employee  as an  active  employee  on the  payroll
       records of the Company.

                                      - 3 -

                                    SECTION 2
                                    ---------

                                   ELIGIBILITY
                                   -----------

2.01   Eligibility.  Any Employee of the Company who: (a) incurs an  Involuntary
       -----------
       Termination of Employment; (b) signs a Release in accordance with Section
       2.03,  which Release shall have become effective under its terms; and (c)
       returns all Company  property in the  possession of the  Employee,  shall
       receive benefits in accordance with Section 3 of this Plan.

2.02   Involuntary Termination. Involuntary Termination of Employment shall be a
       -----------------------
       condition to receipt of benefits  under this Plan. The  determination  of
       whether an Employee has incurred an Involuntary Termination of Employment
       shall be made  based on the good  faith  belief  of the  Corporate  Human
       Resources Department.

2.03   Release.  As a  condition  to receipt of  benefits  under this Plan,  the
       -------
       Employee  must  sign a Release  which  shall  have  become  effective  in
       accordance with its terms.  The failure or refusal of an Employee to sign
       a Release, or the revocation of a Release (to the extent permitted by its
       terms) shall  disqualify the employee from receiving  benefits under this
       Plan. If an Employee  files a legal action  asserting any claim or demand
       within the scope of the Release,  the Company shall retain all rights and
       benefits of the Release and may (a) cancel all future  obligations  under
       the Release;  and (b) recoup the value of all payments and benefits  paid
       under this Plan, together with the Company's costs and attorneys fees.

2.04   Disabled  Employees.  An Employee  receiving benefits under the Company's
       -------------------
       short-term  disability  plan  who:  (a)  following  commencement  of such
       benefits, is scheduled to incur an Involuntary Termination of Employment;
       and (b) meets all the  requirements of Section 2.01, shall be entitled to
       benefits  under this Plan;  provided,  however,  that the number of weeks
       during which  benefits are paid (or deemed to be paid) under Section 3 of
       this Plan shall be  reduced by the number of weeks in which the  Employee
       receives  short-term  disability  benefits  after the  scheduled  date of
       Termination of Employment.

2.05   Alexander  &  Alexander  Employees.  Any  Employee  who was  employed  by
      -----------------------------------
       Alexander &  Alexander  Services,  Inc.,  or any of its  subsidiaries  on
       January 15,  1997,  shall not be eligible  for  benefits  under this Plan
       until the Board or its  designee  shall  amend  this Plan to permit  such
       eligibility.

2.06   Service until Termination of Employment.  An Employee  otherwise entitled
       ---------------------------------------
       to receive  benefits  under  Section  2.01 of this Plan shall not receive
       benefits unless such Employee:  (a) works satisfactorily through the date
       determined by the Company to be the date of  Termination  of  Employment;
       and (b) prior to such date, neither voluntarily terminates employment nor
       is terminated for Cause.

                                     - 4 -


                                    SECTION 3
                                    ---------

                                    BENEFITS
                                    --------


3.01   Company-Provided  Benefits.  An  Employee  eligible  for  benefits  under
       --------------------------
       Section  2.01 shall  receive an amount  equal to one week's  Compensation
       multiplied  by the lesser of: (a) the total of such  Employee's  Years of
       Service plus four; or (b) 30. All  Company-provided  benefits  under this
       Section  3.01,  in the case of a  part-time  Employee,  will be pro rated
       based upon the average  number of hours worked by the part-time  Employee
       and the number of hours  worked by full-time  Employees in the  part-time
       Employee's location.

       For purposes of this Section 3.01, "Years of Service" means the number of
       years of continuous employment with the Company. Partial years of service
       will  be  rounded  to the  closest  Year  of  Service.  With  respect  to
       employment with an employer whose business was acquired by or merged into
       the Company  ("the  Acquired  Employer"),  Years of Service shall include
       employment with the Acquired Employer beginning with such Employee's most
       recent date of hire with the Acquired  Employer  through the date of such
       merger or acquisition. The foregoing applies only to individuals employed
       by the Acquired Employer at the time of the acquisition or merger.

3.02   90-Day Subsidy for Health Benefits.  Participants who elect  continuation
       ----------------------------------
       of  health  care  coverage   under  the   Consolidated   Omnibus   Budget
       Reconciliation Act of 1985 (COBRA), shall be entitled to continue medical
       (including  HMO) and dental  coverage  under COBRA for the 90-day  period
       following  termination  of employment at a cost no greater than that paid
       by similarly situated active Employees.

3.03   Form of  Payment.  Benefits  under  this Plan will be paid in a lump sum,
       ----------------
       unless the Company decides otherwise.

3.04   Other  Benefit  Plans.  No amount paid to a  Participant  under this Plan
       ---------------------
       shall  be  deemed  to be  compensation  with  respect  to the  Employee's
       entitlement  to benefits under any employee  benefit plan  established by
       the Company for its employees unless otherwise  specifically  provided in
       such plan.

3.05   Rehired  Employees.  A Participant who receives  benefits under this Plan
       ------------------
       and who is rehired as an  Employee at any time before the end of a number
       of weeks described in Section 3.01(a),  will be required to reimburse the
       Company for  benefits  paid  during,  or  attributable  to, the period of
       rehire.

                                     - 5 -

3.06   Laws Requiring Payments.  To the extent that any federal,  state or local
       -----------------------
       law,  including  "plant  closing"  laws,  requires  the Company to make a
       payment of any kind to an Employee because of such Employee's involuntary
       termination  due to a  layoff,  reduction  in  force,  plant or  facility
       closing, sale of business, change of control, or other similar event, the
       benefits  provided  under this Plan shall be reduced dollar for dollar or
       eliminated.

3.07   Other  Company-Provided  Payments. The amount of benefits due an Employee
       ---------------------------------
       in accordance with Section 3.01 shall be reduced,  dollar for dollar,  by
       Company-provided payments due the Employee upon Termination of Employment
       under  such other  individual  employment  arrangements  as may cover the
       Employee.

                                     - 6 -

                                    SECTION 4
                                    ---------

                                 ADMINISTRATION
                                 --------------


4.01   Participant  Rights.  If the claim of any Employee for benefits under the
       -------------------
       Plan is denied,  the Company shall provide  adequate notice in writing to
       such claimant,  setting forth the specific  reasons for such denial.  The
       notice shall be written in a manner  calculated  to be  understood by the
       claimant. The Company shall afford such Employee whose claim for benefits
       has been denied 60 days from the date notice of such denial is  delivered
       or mailed in which to appeal the decision in writing to the Committee. If
       the  Employee  appeals  the  decision  in  writing  within  60 days,  the
       Committee  shall review the written  comments and any  submissions of the
       Employee and render its decision  regarding the appeal all within 60 days
       of such appeal.


4.02   Committee Actions.  The Committee may, from time to time, adopt rules and
       -----------------
       regulations  for  carrying  out the Plan.  The  Committee  shall have the
       exclusive right and discretionary authority to construe the provisions of
       the Plan, including without limitation,  the power to interpret disputed,
       ambiguous or uncertain  terms,  and such other powers as may be necessary
       to carry out the  provisions of the Plan.  The Committee  shall also have
       the discretionary authority to determine on appeal all questions relating
       to the  eligibility  of Employees to receive  benefits under the Plan and
       the amount of such benefits,  and resolve all questions pertaining to the
       administration,  interpretation  and application of the Plan  provisions.
       Actions  taken  in good  faith  by the  Company,  the  Committee,  or any
       employee of the Company shall be conclusive and binding on all interested
       parties and shall be given the maximum possible  deference allowed by the
       law. The  Committee  has the  authority  to delegate  its  administrative
       responsibilities.

4.03   Amendment  and  Termination.  The  Plan  may,  at any  time  be  amended,
       ---------------------------
       modified, or terminated by action of the Board.


                                     - 7 -

                                    SECTION 5
                                    ---------

                               GENERAL PROVISIONS
                               ------------------
5.01   Notices. Unless otherwise indicated,  all notices to the Company shall be
       -------
       delivered to the attention of the Secretary of the Company. Any notice or
       filing  required or permitted to be given to the Company  under this Plan
       shall  be  sufficient  if in  writing  and  hand  delivered,  or  sent by
       registered or certified  mail, to the Company at the principal  office of
       the Company.

5.02   Controlling Law. Except to the extent superseded by federal law, the laws
       ---------------
       of Illinois shall be controlling in all matters relating to the Plan.

5.03   Captions.  The captions of Sections and  paragraphs  of this Plan are for
       --------
       convenience  only  and  shall  not  control  or  affect  the  meaning  or
       construction of any of its provisions.

5.04   Action by the  Company.  Any action  required or  permitted  by a Company
       ----------------------
       under  the Plan  shall be by  resolution  of its  Board or any  person or
       persons authorized by resolution of its Board.

5.05   Facility of Payment.  Any amounts  payable  under this Plan to any person
       -------------------
       under legal disability or who, in the judgment of the Company,  is unable
       to  properly  manage  his  financial  affairs  may be paid  to the  legal
       representative  of such  person or may be applied for the benefit of such
       person in any manner which the Company may select.

5.06   Severability.  Whenever  possible,  each  provision  of the Plan shall be
       ------------
       interpreted in such manner as to be effective and valid under  applicable
       law.  If,  however,  any  provision  of the  Plan  shall  be  held  to be
       prohibited by or invalid under  applicable  law, then (a) such  provision
       shall be deemed  amended to, and to have  contained  from the outset such
       language as shall be  necessary  to,  accomplish  the  objectives  of the
       provision as originally  written to the fullest extent  permitted by law;
       and (b) all other  provisions  of the Plan shall remain in full force and
       effect.

5.07   Liability.  No member of the Board,  no employee of the  Company,  and no
       ---------
       member of the Committee  (nor the  Committee  itself) shall be liable for
       any act or action under this Plan whether of omission or  commission,  by
       any other member or employee or by any agent to whom duties in connection
       with the  administration  of the Plan have been  delegated  or, except in
       circumstances  involving his bad faith,  gross  negligence or fraud,  for
       anything  done or omitted to be done by himself.  The Company  will fully
       indemnify  and  hold  the  members  of the  Committee  harmless  from any
       liability under this Plan, except in circumstances  involving a Committee
       member's  bad  faith,  gross  negligence,  or fraud.  The  Company or the
       Committee  may  consult  with legal  counsel,  who may be counsel for the
       Company or other counsel,  with respect to its obligation or duties 

                                     - 8 -


       under this Plan,  or with  respect  to any  action or  proceeding  or any
       question of law, and shall not be liable with respect to any action taken
       or omitted by it in good faith pursuant to the advice of counsel.

5.08   Successors.  The  provisions  of the Plan  shall  bind  and  inure to the
       ----------
       benefit  of  the  Company  and  its  successors  and  assigns.  The  term
       "successors"  as used  herein  shall  include  any  corporation  or other
       business  entity  which  shall by  merger,  consolidation,  purchase,  or
       otherwise, acquire all or substantially all of the business and assets of
       the Company and  successors  of any such  corporation  or other  business
       entity.

5.09   Unfunded Status of the Plan. Payments made to the Participant pursuant to
       ---------------------------
       the Plan  shall be made only  from the  general  assets  of the  Company.
       Nothing  contained  in this Plan shall be deemed to create a trust of any
       kind.

                                     - 9 -

IN WITNESS WHEREOF, Aon Corporation hereby adopts the Aon Severance Plan,

effective as set forth above, as of this 5th   day of May             , 1997.
                                        -------       ----------------    --


                                             AON CORPORATION


                                             By:
                                             
                                             /s/ Daniel T. Cox
                                             -----------------------
                                             Daniel T. Cox
                                             Executive Vice President

                                     - 10 -

                                   APPENDIX A

                               AON SEVERANCE PLAN
                               ------------------

                          WAIVER AND RELEASE OF CLAIMS
                          ----------------------------


In exchange for benefits to be provided to me under the Aon Severance  Plan (the
"Plan") , which I acknowledge I am not otherwise  entitled to receive,  I freely
and voluntarily agree to this WAIVER AND RELEASE OF CLAIMS.


1.       In signing  this  WAIVER AND  RELEASE  OF  CLAIMS,  I hereby  waive and
         release  any and all claims that I may ever have had or that I now have
         against the following persons and organizations:

         a.       Aon Corporation, its affiliates,  successors and subsidiaries;
                  and,
         b.       Any and all officers, directors,  employees,  shareholders and
                  agents of Aon  Corporation,  its  affiliates,  successors  and
                  subsidiaries.

2.       I understand and agree that, in signing this document, I am waiving and
         releasing  any and all claims of  whatever  nature that I may ever have
         had or now  have  against  the  persons  and  organizations  listed  in
         paragraph  1. I  understand  and agree that among the claims  that I am
         waiving and releasing are the following:

         a.       Claims of age  discrimination  in employment under the federal
                  Age Discrimination in Employment Act of 1967;
         b.       Claims of race,  color,  sex,  national  origin and  religious
                  discrimination  or harassment in employment under Title VII of
                  the Civil Rights Act of 1964, as amended, and the Civil Rights
                  Act of 1866, 42 U.S.C. ss. 1981, as amended;
         c.       Claims of disability  discrimination  under the Americans With
                  Disabilities Act;
         d.       Claims  of   discrimination  in  employment  under  any  other
                  federal,  state or local  statute,  ordinance,  regulation  or
                  constitution;
         e.       Claims under any employment  agreement or any claims of breach
                  of contract; and,
         f.       Any common law or statutory  claims of wrongful  discharge and
                  any other common law tort or statutory claims.

         I  understand  and agree that I am waiving  and  releasing  any and all
         claims that I may ever have had or that I now have, regardless of their
         nature or  origin,  and that the fact that such  claim is not listed in
         subparagraphs  (a) through (f) above,  does not mean that such claim is
         not included in this WAIVER AND RELEASE OF CLAIMS.


3.       I agree  that I will  never  sue any of the  persons  or  organizations
         listed in  paragraph  1 and I further  agree  that I will never seek or
         receive  damages for any claim or charge of employment  discrimination,
         for any claim  released by this  WAIVER AND  RELEASE OF CLAIMS.  I also
         agree to  withdraw  any pending  lawsuit I may have  against any of the

                                     - 11 -

         persons  or  organizations  listed in  paragraph  1  arising  out of my
         employment, including the termination of my employment.


4.       In signing this agreement,  I agree and understand that this WAIVER AND
         RELEASE OF CLAIMS  will be binding not only on me but also on my heirs,
         administrators  and assigns with respect to the claims  covered by this
         agreement.  As of the date of my signing of this agreement, I have made
         no assignment of any claims against any of the persons or organizations
         described in paragraph 1.

5.       I hereby  acknowledge  that,  at the time I was given  this  WAIVER AND
         RELEASE OF CLAIMS,  I was  informed  in writing  that I had at least 45
         days  from  the  date I  received  all  the  information  described  in
         paragraph  below in which to consider  whether I would sign this WAIVER
         AND RELEASE OF CLAIMS. I also acknowledge that, at the time I was given
         this WAIVER AND  RELEASE OF CLAIMS,  I was  informed in writing  that I
         should consult with an attorney before signing this  agreement.  I have
         had an opportunity to consult with an attorney and have either had such
         consultations or have decided of my own free will that I will sign this
         agreement without consulting with legal counsel.

6.       I acknowledge  that, at the time I was given this WAIVER AND RELEASE OF
         CLAIMS,  I was given a complete  description  of the Plan,  including a
         description  of the group of persons who are  covered by this  program,
         the  rules  of  eligibility  and any  time  limits  applicable  to such
         program. Finally, I acknowledge that I have received a list of ages and
         job  titles  of all  individuals  in my  organizational  unit  who  are
         eligible or were selected to receive benefits under the Plan as well as
         the ages and job titles of  individuals in my  organizational  unit who
         are not  eligible or were not  selected to receive  benefits  under the
         Plan.

7.       I acknowledge that I have been informed that I may revoke my acceptance
         of this  WAIVER  AND  RELEASE OF CLAIMS by  delivering  a letter to the
         Corporate Human Resources Department (see address below),  within seven
         days of the date I have signed this  agreement.  I understand that this
         WAIVER AND RELEASE OF CLAIMS will not become effective until the eighth
         day  following my signing of this  agreement.  I understand  and intend
         that,  in the event I do not  revoke my  acceptance  of this  agreement
         within the seven-day  period  described in this paragraph,  this WAIVER
         AND RELEASE OF CLAIMS will be legally binding and enforceable on me, my
         heirs, administrators and assigns.

8.       I agree to continue to respect the trade secrets and other confidential
         information  to which I have had access  while  employed.  Insofar as I
         have already  signed any written  agreement or  agreements  not to deal
         with  customers  or clients or not to hire  employees  of my  employing
         company or its  affiliates  for any period of time after  cessation  of
         employment,  I confirm that I shall fulfill the terms of such agreement
         or agreements.

                                     - 12 -

9.       This  WAIVER AND  RELEASE OF CLAIMS will be  interpreted  and  enforced
         according  to the laws of the  state of  Illinois.  If any part of this
         WAIVER  AND  RELEASE  OF  CLAIMS  is  judged  by a court  of  competent
         jurisdiction to be illegal, invalid or inoperable,  then that part only
         will  be  stricken.   A  suitable  and  equitable   provision  will  be
         substituted  in order to carry out,  so far as may be  enforceable  and
         valid,  the intent and purpose of the  stricken  part,  and the rest of
         this  WAIVER AND  RELEASE  OF CLAIMS  will  continue  in full force and
         effect.


I  acknowledge  that the number of years of service used to calculate my benefit
under the Aon Severance Plan is ____, based on my hire date of , 19__.


___________________________                  _____________________________
NAME (Please Print)                          SIGNATURE


___________________________                  _____________________________
DATE                                         SOCIAL SECURITY NUMBER


Return the original signed copy of this form on or before the 45th day after you
have received all the information described in paragraph 6 (above) to:



                  Corporate Human Resources
                  ____________________________

                  ____________________________
                  123 North Wacker Drive
                  Chicago, IL   60606



                                     - 13 -