SECURITIES AND EXCHANGE COMMISSION
                             WASHINGTON, D.C. 20549

                                    FORM 11-K





__X__    Annual Report Pursuant to Section 15(d) of the Securities
                  Exchange Act of 1934

                  For the fiscal year ended December 31, 2002

                                       OR

_____             Transition Report Pursuant to Section 15(d) of the
                  Securities Exchange Act of 1934



                  A.       Full  title of the plan and the  address of the plan,
                           if different from the issuer named below:

                                Aon Savings Plan


                  B.       Name of the issuer of the securities held pursuant to
                           the plan and the address of its  principal  executive
                           office:


                                 Aon Corporation
                              200 E. Randolph Drive
                             Chicago, Illinois 60601









                               S I G N A T U R E S

Pursuant to the  requirements of the Securities  Exchange Act of 1934, the Plan,
by the Plan  Administrator,  the Committee,  has caused this annual report to be
signed on its  behalf by the  undersigned,  thereunto  duly  authorized,  in the
County of Cook and the State of Illinois on the 25th day of June, 2003.

AON SAVINGS PLAN

BY THE COMMITTEE



/s/ THOMAS STACHURA                         /s/ JOHN A. RESCHKE
-------------------                         --------------------
Thomas Stachura                             John A. Reschke



                                      - 2 -


                 FINANCIAL STATEMENTS AND SUPPLEMENTAL SCHEDULE

                                AON SAVINGS PLAN

                     Years Ended December 31, 2002 and 2001

                       With Report of Independent Auditors

                    Employer Identification Number 36-3051915

                                   Plan # 020






                                AON SAVINGS PLAN

                 FINANCIAL STATEMENTS AND SUPPLEMENTAL SCHEDULE

                     Years ended December 31, 2002 and 2001


                                    CONTENTS



Report of Independent Auditors                                                 1

Financial Statements

         Statement of Assets Available for Benefits
         at December 31, 2002                                                  2

         Statement of Assets Available for Benefits
         at December 31, 2001                                                  3

         Statement of Changes in Assets Available for Benefits
         for the year ended December 31, 2002                                  4

         Statement of Changes in Assets Available for Benefits
         for the year ended December 31, 2001                                  5

Notes to Financial Statements                                                  6

Supplemental Schedule:

         Schedule H, Line 4i - Schedule of Assets (Held At
         End of Year)                                                         13






                         Report of Independent Auditors


The Participants and Administrative Committee
Aon Savings Plan


We have audited the accompanying  statements of assets available for benefits of
Aon Savings Plan as of December 31, 2002 and 2001, and the related statements of
changes  in assets  available  for  benefits  for the years  then  ended.  These
financial  statements  are the  responsibility  of the  Plan's  management.  Our
responsibility  is to express an opinion on these financial  statements based on
our audits.

We conducted our audits in accordance with auditing standards generally accepted
in the United States. Those standards require that we plan and perform the audit
to obtain reasonable  assurance about whether the financial  statements are free
of material misstatement. An audit includes examining, on a test basis, evidence
supporting  the amounts and  disclosures in the financial  statements.  An audit
also includes assessing the accounting principles used and significant estimates
made by  management,  as well as  evaluating  the  overall  financial  statement
presentation. We believe our audits provide a reasonable basis for our opinion.

In our opinion,  the financial  statements  referred to above present fairly, in
all material respects, the assets available for benefits of the Plan at December
31, 2002 and 2001, and the changes in its assets  available for benefits for the
years then ended, in conformity with accounting principles generally accepted in
the United States.

Our audits  were  performed  for the  purpose of forming an opinion on the basic
financial statements taken as a whole. The accompanying supplemental schedule of
assets (held at end of year) as of December 31, 2002,  is presented for purposes
of additional  analysis and is not a required part of the financial  statements,
but is supplementary information required by the Department of Labor's Rules and
Regulations for Reporting and Disclosure  under the Employee  Retirement  Income
Security Act of 1974. This  supplemental  schedule is the  responsibility of the
Plan's management.  The supplemental schedule has been subjected to the auditing
procedures  applied in our audits of the basic financial  statements and, in our
opinion,  is fairly  stated in all  material  respects  in relation to the basic
financial statements taken as a whole.




June 4, 2003                                                Ernst & Young LLP
Chicago, Illinois

                                      - 1 -



                                                                                 Employer Plan Identification # 36-3051915
                                                                                 Plan # 020



                                                                                       AON SAVINGS PLAN
                                                                          STATEMENT OF ASSETS AVAILABLE FOR BENEFITS
                                                                                      DECEMBER 31, 2002
                                                                                        (in thousands)
                                                                   ------------------------------------------------------

                                                                                           ESOP
                                                                      SAVINGS            ALLOCATED
     ASSETS:                                                           PLAN               ACCOUNT              TOTAL
     ------                                                        ----------------    ----------------    --------------

                                                                                                
     Investments, at Fair Value:
          Aon Corporation Common Stock                           $       144,755     $       110,361     $       255,116
          Brokerage Accounts-Other Common and
             Preferred Stocks and Mutual Funds                             4,917                   -               4,917
          Investments held in Mutual Funds:
             AIM Liquid Asset Fund                                       248,777                   -             248,777
             Vanguard REIT Index Fund                                     32,568                   -              32,568
             Vanguard Admiral Intermediate Term Treasury Fund             85,778                   -              85,778
             INVESCO Dynamics Fund                                        16,124                   -              16,124
             Dodge & Cox Common Stock Fund                                50,682                   -              50,682
             PIMCO Total Return Fund                                      31,799                   -              31,799
             Montag & Caldwell Growth Fund                                 7,595                   -               7,595
             Managers Special Equity Fund                                 13,666                   -              13,666
             Templeton Emerging Markets Fund                               2,916                   -               2,916
          Investments held in Collective Trusts:
             INVESCO Asset Allocation Fund                               117,128                   -             117,128
             INVESCO 500 Index Fund                                      171,542                   -             171,542
             INVESCO International Equity Fund                            28,247                   -              28,247
          Short-Term Investment Funds                                      1,499                   -               1,499
          Participant Loans                                               18,957                   -              18,957
                                                                   ----------------    ----------------    --------------

                                                                         976,950             110,361           1,087,311


     Company Contribution Receivable                                      30,437              17,760              48,197

                                                                   ----------------    ----------------    --------------
     ASSETS AVAILABLE FOR BENEFITS                               $     1,007,387     $       128,121     $     1,135,508
                                                                   ================    ================    ==============



          See notes to financial statements.

                                     - 2 -



                                                                                 Employer Plan Identification # 36-3051915
                                                                                 Plan # 020


                                                                                       AON SAVINGS PLAN
                                                                         STATEMENT OF ASSETS AVAILABLE FOR BENEFITS
                                                                                       DECEMBER 31, 2001
                                                                                        (in thousands)
                                                                   ------------------------------------------------------

                                                                                           ESOP
                                                                      SAVINGS            ALLOCATED
     ASSETS:                                                           PLAN               ACCOUNT              TOTAL
     -------                                                       ----------------    ----------------    --------------

                                                                                                
     Investments, at Fair Value:
          Aon Corporation Common Stock                           $       262,108     $       202,435     $       464,543
          Brokerage Accounts-Other Common and
             Preferred Stocks and Mutual Funds                             6,200                   -               6,200
          Investments held in Mutual Funds:
             Aon Money Market Fund                                       264,987                   -             264,987
             Aon Government Securities Fund                               49,054                   -              49,054
             Aon Asset Allocation Fund                                   136,943                   -             136,943
             Vanguard REIT Index Fund                                     26,084                   -              26,084
             Vanguard Admiral Intermediate Term Treasury Fund             12,401                   -              12,401
             INVESCO Dynamics Fund                                        21,024                   -              21,024
             Dodge & Cox Common Stock Fund                                31,868                   -              31,868
             PIMCO Total Return Fund                                      14,638                   -              14,638
             Montag & Caldwell Growth Fund                                 7,387                   -               7,387
             Managers Special Equity Fund                                 13,151                   -              13,151
             Templeton Emerging Markets Fund                                 936                   -                 936
          Investments held in Collective Trusts:
             INVESCO 500 Index Fund                                      236,815                   -             236,815
             INVESCO Core-Balanced Fund                                    3,773                   -               3,773
             INVESCO International Equity Fund                            32,212                   -              32,212
          Short-Term Investment Funds                                      1,626                   -               1,626
          Participant Loans                                               19,269                   -              19,269
                                                                   ----------------    ----------------    --------------

                                                                       1,140,476             202,435           1,342,911


     Company Contribution Receivable                                      26,402              16,257              42,659

                                                                   ----------------    ----------------    --------------
     ASSETS AVAILABLE FOR BENEFITS                               $     1,166,878     $       218,692     $     1,385,570
                                                                   ================    ================    ==============



          See notes to financial statements.

                                      - 3 -



                                                                                      Employer Plan Identification # 36-3051915
                                                                                      Plan #020


                                                                               AON SAVINGS PLAN
                                                          STATEMENT OF CHANGES IN ASSETS AVAILABLE FOR BENEFITS
                                                                         YEAR ENDED DECEMBER 31, 2002
                                                                                   (in thousands)
                                                      ------------------------------------------------------------------------



                                                                                                 ESOP
                                                                             SAVINGS           ALLOCATED
                                                                              PLAN              ACCOUNT             TOTAL
                                                                          --------------     --------------     --------------

                                                                                                     
   NET INVESTMENT INCOME (LOSS)
      Interest Income                                                   $         1,529    $             1    $         1,530
      Net Realized and Unrealized Depreciation
        in Fair Value of Investments                                           (204,840)           (97,587)          (302,427)
      Aon Corporation Dividends                                                   5,933              4,788             10,721
      Other Dividends                                                            15,603                  -             15,603
      Management and Administrative Fees                                         (1,891)              (136)            (2,027)
                                                                          --------------     --------------     --------------

   TOTAL NET INVESTMENT LOSS                                                   (183,666)           (92,934)          (276,600)

   CONTRIBUTIONS
      Company                                                                    30,437             17,760             48,197
      Participants                                                               86,106                  -             86,106
      Rollovers                                                                  11,172                  -             11,172
                                                                          --------------     --------------     --------------

   TOTAL CONTRIBUTIONS                                                          127,715             17,760            145,475

   ALLOCATIONS

      ESOP Diversification                                                        1,352             (1,352)                 -
                                                                          --------------     --------------     --------------

   TOTAL ALLOCATIONS                                                              1,352             (1,352)                 -

   OTHER CHANGES

   Benefit Payments                                                            (106,506)           (14,045)          (120,551)
   Plan Mergers                                                                   1,614                  -              1,614

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

   TOTAL OTHER CHANGES                                                         (104,892)           (14,045)          (118,937)
                                                                          --------------     --------------     --------------

   NET DECREASE IN ASSETS AVAILABLE
       FOR BENEFITS                                                            (159,491)           (90,571)          (250,062)

   ASSETS AVAILABLE FOR BENEFITS
        AT BEGINNING OF YEAR                                                  1,166,878            218,692          1,385,570

                                                                          --------------     --------------     --------------
   ASSETS AVAILABLE FOR BENEFITS
        AT END OF YEAR                                                  $     1,007,387    $       128,121    $     1,135,508
                                                                          ==============     ==============     ==============


       See notes to financial statements.


                                      - 4 -





                                                                                      Employer Plan Identification # 36-3051915
                                                                                      Plan #020

                                                                               AON SAVINGS PLAN
                                                          STATEMENT OF CHANGES IN ASSETS AVAILABLE FOR BENEFITS
                                                                         YEAR ENDED DECEMBER 31, 2001
                                                                                   (in thousands)
                                                      ------------------------------------------------------------------------



                                                                                                 ESOP
                                                                             SAVINGS           ALLOCATED
                                                                              PLAN              ACCOUNT             TOTAL
                                                                          --------------     --------------     --------------

                                                                                                     
   NET INVESTMENT INCOME (LOSS)
      Interest Income                                                   $         1,760    $             2    $         1,762
      Net Realized and Unrealized Appreciation
       (Depreciation) in Fair Value of Investments                              (53,748)             6,396            (47,352)
      Aon Corporation Dividends                                                   7,231              5,212             12,443
      Other Dividends                                                            18,464                  -             18,464
      Management and Administrative Fees                                         (1,817)              (162)            (1,979)
                                                                          --------------     --------------     --------------

   TOTAL NET INVESTMENT INCOME (LOSS)                                           (28,110)            11,448            (16,662)

   CONTRIBUTIONS
      Company                                                                    26,402             16,257             42,659
      Participants                                                               75,186                  -             75,186
      Rollovers                                                                  15,045                  -             15,045
                                                                          --------------     --------------     --------------

   TOTAL CONTRIBUTIONS                                                          116,633             16,257            132,890

   ALLOCATIONS

      ESOP Diversification                                                          493               (493)                 -
                                                                          --------------     --------------     --------------

   TOTAL ALLOCATIONS                                                                493               (493)                 -

   OTHER CHANGES

   Benefit Payments                                                            (120,094)           (23,062)          (143,156)
   Plan Mergers                                                                  13,820                  -             13,820

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

   TOTAL OTHER CHANGES                                                         (106,274)           (23,062)          (129,336)
                                                                          --------------     --------------     --------------

   NET INCREASE (DECREASE) IN ASSETS AVAILABLE
       FOR BENEFITS                                                             (17,258)             4,150            (13,108)

   ASSETS AVAILABLE FOR BENEFITS
        AT BEGINNING OF YEAR                                                  1,184,136            214,542          1,398,678

                                                                          --------------     --------------     --------------
   ASSETS AVAILABLE FOR BENEFITS
        AT END OF YEAR                                                  $     1,166,878    $       218,692    $     1,385,570
                                                                          ==============     ==============     ==============


       See notes to financial statements.


                                      - 5 -


                                       Employer Plan Identification # 36-3051915
                                       Plan # 020




                                AON SAVINGS PLAN

                          NOTES TO FINANCIAL STATEMENTS

                     Years Ended December 31, 2002 and 2001

1.       DESCRIPTION OF PLAN

         GENERAL

         The Aon  Savings  Plan  (the  Plan)  was  authorized  by the  Board  of
         Directors of Aon  Corporation  (the Company or Plan  Sponsor).  It is a
         defined  contribution  plan  with  a  salary  deferral  feature  and an
         employee stock  ownership  (ESOP)  feature.  The Plan is subject to the
         provisions  of the  Employee  Retirement  Income  Security  Act of 1974
         (ERISA).  Effective January 1, 2002, participants in the ASI Solutions,
         Inc.  401(k)  Retirement Plan (ASI Plan) became eligible to participate
         in the Plan. Effective January 1, 2002, the FESC Employees Savings Plan
         (FESC Plan) merged into the Plan and as a result,  assets approximating
         $1.6 million were transferred into the Plan.  Effective August 1, 2001,
         participants  in the McLagan  Partners Inc.  401(k) Profit Sharing Plan
         (McLagan Plan) became  eligible to  participate in the Plan.  Effective
         March 31,  2001,  the ASA  Savings  Plan  merged into the Plan and as a
         result,  assets  approximating  $13.8 million were transferred into the
         Plan.

         Certain Plan assets are held by the Aon Funds, an affiliated,  open-end
         management investment company.  Assets in the Aon Funds were liquidated
         in 2002.  The  assets  of the  ESOP  portion  of the Plan are  invested
         primarily in common stock of the Company. Additionally,  certain assets
         are invested by the Trustees as deemed  advisable in order for the Plan
         to meet its cash flow needs.

         The   following   description   of  the  Plan   provides  only  general
         information.  Participants of the Plan should refer to the Summary Plan
         Description for a more complete description of the Plan.

         ELIGIBILITY AND PARTICIPATION

         Employees other than field sales agents or employees  scheduled to work
         less than 20 hours per week are  immediately  eligible to  participate.
         Field sales agents and  employees  scheduled to work less than 20 hours
         per week are  eligible  to  participate  after  completing  one year of
         service.  Participants must complete one year of service to be eligible
         for company matching contributions.

                                     - 6 -


1. DESCRIPTION OF PLAN (CONTINUED)

         CONTRIBUTIONS

         PARTICIPANT  - Participant  contributions  are made by means of regular
         payroll deductions.  Non-highly compensated participants, as defined by
         the  Internal  Revenue  Code  (IRC),  may  elect to make  contributions
         between  1% and 16% of their  compensation,  as  defined  by the  Plan.
         Highly  compensated  participants,  as defined by the IRC, may elect to
         make contributions between 1% and 8% of their compensation,  as defined
         by the Plan.  Participant  contributions are limited to amounts allowed
         by  the  Internal  Revenue  Service  (IRS).  Accordingly,  the  maximum
         participant  contribution  was $11,000 in 2002 and $10,500 in 2001.  In
         addition to regular participant  contributions,  catch-up contributions
         of up to $1,000 were allowed in 2002 for any  participants who were age
         50 or older during the Plan year.

         COMPANY - The Company  contributes an amount equal to 100% of the first
         3% of a participant's  compensation  that a participant  contributes to
         the Plan (75% of a participant's compensation up to 4% for employees of
         Aon Human Capital  Services,  LLC in 2002). The Company makes a further
         contribution  to the ESOP  portion  of the  Plan  equal to 75% (50% for
         field sales agents) of the next 3% of a participant's compensation that
         is contributed to the Plan. In 2002 and 2001, the ESOP contribution was
         made in shares of common stock of the  Company.  Employees of Aon Human
         Capital  Services,  LLC are not eligible for this contribution in 2002.
         The Plan  requires that a  participant  be actively  employed as of the
         last day of the Plan year and they must have been employed for one year
         in order to receive a Company contribution.

         Contributions  to the  ESOP  portion  of  the  Plan  are  automatically
         invested in common stock of the Company.

         INVESTMENT OPTIONS

         Contributions  to the Plan,  other  than for the ESOP  portion,  may be
         invested in any of the various investment  alternatives  offered by the
         Plan in any whole percentages.  Additionally, a Self-Managed Account is
         offered   whereby   participants   can   invest   their   self-directed
         contributions in various stock, mutual funds and other investments.

         PARTICIPANT ACCOUNTS

         Each   participant's   account  is  credited  with  the   participant's
         contribution and allocations of a) the Company's contributions, b) Plan
         earnings(losses),   and  c)  forfeitures  of  terminated  participants'
         non-vested accounts.  The benefit to which a participant is entitled is
         the benefit that can be provided from the participant's account.

                                     - 7 -


1. DESCRIPTION OF PLAN (CONTINUED)

         VESTING

         For the ESOP portion of the Plan, a participant vests in 20% increments
         per year and becomes 100% vested after completion of five years of plan
         service.  Forfeitures  of  non-vested  accounts  are  allocated  to the
         remaining  participants.  In 2002,  forfeitures  are only  allocated to
         those participants who received a company  contribution.  The amount of
         forfeitures  allocated to participants was $432,000 and $673,000 of the
         Company's common stock in 2002 and 2001, respectively.

         For the non-ESOP portion of the Plan,  participants are fully vested in
         their  contributions plus actual earnings thereon.  Participants become
         100% vested in the remainder of their account  balance after five years
         of  plan  service,  according  to a  graded  schedule.  Forfeitures  of
         non-vested  accounts are allocated to the remaining  participants.  The
         amount of  forfeitures  allocated  to  participants  was  $617,000  and
         $833,000 for 2002 and 2001, respectively.

         BENEFIT PAYMENTS

         For the ESOP portion of the Plan, a participant's  entire account shall
         be paid to the participant or designated beneficiary in a lump sum upon
         normal retirement,  permanent  disability or death. The participant may
         elect payment in the form of Company common stock or cash.

         For the non-ESOP portion,  on termination of service, a participant may
         elect to receive  either a lump sum amount equal to the value of his or
         her  account  or monthly  installments  over a period not to exceed ten
         years.

         PLAN TERMINATION

         Although it has not  expressed any intent to do so, the Company has the
         right under the Plan to discontinue its  contributions  at any time and
         to terminate the Plan subject to the provisions of ERISA.  In the event
         of Plan  termination,  participants  will  become  100% vested in their
         accounts.

         PARTICIPANT LOANS

         Under the loan provision of the Plan, each participant is permitted one
         loan in a twelve month period and the outstanding  balance of all loans
         made to a  participant  may not  exceed the lesser of $50,000 or 50% of
         the vested  portion of the  participant's  account,  excluding the ESOP
         portion of the account.  The interest rate for each loan is equal to 1%
         plus the prime rate as quoted in The Wall  Street  Journal for the last
                                          -------------------------
         day of the  month  preceding  the loan  request.  Loans  are made for a
         period of up to five years,  except for  residential  loans that have a
         fixed repayment period of ten years.


                                     - 8 -


2.       SIGNIFICANT ACCOUNTING POLICIES

         BASIS OF ACCOUNTING

         The  financial  statements of the Plan are prepared on an accrual basis
         in accordance  with  accounting  principles  generally  accepted in the
         United States.

         INVESTMENT VALUATION AND INCOME RECOGNITION

         Investments are carried at fair value, which for marketable  securities
         is based on quotations obtained from national securities  exchanges and
         various  other   sources.   Participant   loans  are  valued  at  their
         outstanding balances which approximates fair value.

         Interest  income is recorded as earned.  Dividend income is recorded on
         the ex-dividend  date.  Realized gains or losses on investments are the
         difference  between the proceeds  received and the cost of  investments
         sold as determined on a first-in,  first-out  basis.  The change in the
         difference  between fair value and the cost of  investments is reported
         as unrealized appreciation or depreciation of investments.

         ADMINISTRATIVE EXPENSES

         Administrative   expenses  of  the  Plan,  including  expenses  of  the
         Trustees,  are paid from the Plan assets, except to the extent that the
         Company,  at its  discretion,  may  decide  to pay such  expenses.  The
         Company did not pay any Plan expenses in 2002 or 2001.

         USE OF ESTIMATES

         The  preparation  of  the  financial   statements  in  conformity  with
         accounting  principles generally accepted in the United States requires
         management to make  estimates and  assumptions  that affect the amounts
         reported in the financial  statements and  accompanying  notes.  Actual
         results could differ from those estimates.

         RECLASSIFICATIONS

         Certain amounts in the 2001 financial statements have been reclassified
         to conform with the 2002 presentation.

3.       INVESTMENTS

         Institutional  Trust  Company (ITC) is custodian of the Plan assets and
         Trustee  for all  Plan  assets  except  the ESOP  shares.  For the ESOP
         shares,  State  Street  Bank and  Trust  Company  is the  Trustee.  The
         Trustees are named  fiduciaries  under ERISA.  As used herein,  Trustee
         refers to the ITC and State Street Bank and Trust Company  individually
         and collectively.

                                     - 9 -


3. INVESTMENTS (CONTINUED)

         During  2002 and 2001 the  Plan's  investments  (including  investments
         bought,  sold and held during the year)  appreciated  (depreciated)  in
         fair value as follows (in thousands):




                                                                                 December 31
                                                                       2002                       2001
                                              --------------------------------------------------------------------
                                                                  Net Realized                      Net Realized
                                                                and Unrealized                    and Unrealized
                                                                  Appreciation                      Appreciation
                                                                (Depreciation)                    (Depreciation)
                                                                 in Fair Value                     in Fair Value
                                                                of Investments                    of Investments
                                                     Fair               During           Fair             During
                                                     Value            the Year           Value          the Year
                                              --------------------------------------------------------------------
                                                                                     
Investments, at fair value:
Aon Corporation Common Stock                  $        255,116 $      (215,483) $        464,543 $         20,634
Brokerage Accounts-Other
  Common and Preferred Stocks
  and Mutual Funds                                       4,917          (2,298)            6,200          (1,790)
Investments in Mutual Funds:
  Aon Money Market Fund                                      -                -          264,987                -
  Aon Government Securities Fund                             -            1,618           49,054            (163)
  Aon Asset Allocation Fund                                  -          (4,877)          136,943         (19,660)
  Aon REIT Index Fund                                        -                -                -            1,645
  AIM Liquid Asset Fund                                248,777                -                -                -
  Vanguard REIT Index Fund                              32,568          (1,430)           26,084              595
  INVESCO Dynamics Fund                                 16,124          (8,044)           21,024          (7,776)
  Dodge & Cox Stock Fund                                50,682          (7,024)           31,868              316
  PIMCO Total Return Fund                               31,799              284           14,638            (168)
  Montag & Caldwell Growth Fund                          7,595          (2,151)            7,387            (375)
  Managers Special Equity Fund                          13,666          (3,992)           13,151            (734)
  Templeton Emerging Markets
      Fund                                               2,916            (326)              936             (56)
  Vanguard Admiral Intermediate
      Term Treasury Fund                                85,778            1,443           12,401               52
Investments in Collective Trusts
  INVESCO Asset Allocation Fund                        117,128          (3,644)                -                -
  INVESCO 500 Index Fund                               171,542         (52,658)          236,815         (33,867)
  INVESCO Core-Balanced Fund                                 -            (550)            3,773            (169)
  INVESCO International
        Equity Fund                                     28,247          (3,295)           32,212          (5,836)
Short-Term Investment Funds                              1,499                -            1,626                -
                                              --------------------------------------------------------------------
  Total                                       $      1,068,354 $      (302,427) $      1,323,642 $       (47,352)
                                              --------------------------------------------------------------------


                                     - 10 -



3. INVESTMENTS (CONTINUED)

         The fair value of individual  investments  that represent 5% or more of
         the Plan's assets is as follows (in thousands):




                                                                           December 31
                                                               ------------------------------------

                                                                    2002                    2001
                                                                    ----                    ----
                                                                                  
         Aon Corporation, Common Stock                         $   255,116*             $  464,899*
         Investments held in Mutual Funds:
           Aon Money Market Fund                                         -                 264,987
           AIM Liquid Asset Fund                                   248,777                       -
           Aon Asset Allocation Fund                                     -                 136,943
           Vanguard Admiral Intermediate Term
              Treasury Fund                                         85,778                      **

         Investments in Collective Trusts:
           INVESCO 500 Index Fund                                  171,542                 236,815
           INVESCO Asset Allocation Fund                           117,128                       -


         *Includes $110,361 and $202,435 of non-participant directed investments
           in 2002 and 2001, respectively.

         **Below 5% threshold.




4.       INCOME TAX STATUS

         The Plan has received a  determination  letter from the IRS dated April
         10, 1995,  stating that the Plan is qualified  under section  401(a) of
         the IRC and,  therefore,  the related  trust is exempt  from  taxation.
         Subsequent to this issuance of the determination  letter,  the Plan was
         amended and restated.  Once qualified,  the Plan is required to operate
         in  conformity  with the IRC to maintain  its  qualification.  The Plan
         Administrative  Committee  believes  the  Plan  is  being  operated  in
         compliance with the applicable  requirements of the IRC and, therefore,
         believes that the Plan, as amended,  is qualified and the related trust
         is tax exempt.

5.       SUBSEQUENT EVENTS

         Effective  January 1, 2003, the Aon Common Stock Fund and the ESOP Fund
         were  merged  into a single  fund  called  the Aon Common  Stock  ESOP.
         Participants have the option to reinvest dividends in additional shares
         of Aon Stock in the Plan or receive  dividends  in cash.  Additionally,
         effective  January 1, 2003,  participants  are  allowed to  immediately
         diversify  any  company  matching  contributions  allocated  to the Aon
         Common Stock ESOP Fund. As a result,  the ESOP Allocated  Account is no
         longer considered a non-participant directed investment.

                                     - 11 -


5.       SUBSEQUENT EVENTS (CONTINUED)

         On January 1, 2003,  the ASI Plan and the McLagan Plan were merged into
         the Plan and as a result,  assets  approximating $3.2 million and $2.9,
         respectively, were transferred into the Plan.

                                     - 12 -



                                                                               Employer Identification # 36-3051915
                                                                               Plan #  020
                                                  AON SAVINGS PLAN
                           Schedule H, Line 4i - SCHEDULE OF ASSETS (HELD AT END OF YEAR)
                                                 December 31, 2002

                                                             Number of Shares                      Current Value
                                                             ----------------
Identity of Issuer                                           Principal Amount                        (thousands)
------------------------------------------------------------------------------------------------------------------
                                                                                           
AON COMMON STOCK FUND
---------------------

COMMON STOCK

     Aon Corporation
     Common Stock, 1.00 par*                                   7,677,592                         $        144,568
                                                                                                    ==============


MONEY MARKET FUND
-----------------

MUTUAL FUND

     Investments held in the AIM
     Liquid Asset Fund                                       248,777,408                         $        248,777
                                                                                                    ==============


TOTAL RETURN FUND
-----------------

COLLECTIVE TRUST

     Investments held in the INVESCO
     Asset Allocation Fund*                                   12,075,097                         $        117,128
                                                                                                    ==============


COMMON STOCK INDEX FUND
-----------------------

COLLECTIVE TRUST

     Investments held in the INVESCO
     500 Index Fund*                                           7,890,595                         $        171,542
                                                                                                    ==============


REAL ESTATE SECURITIES FUND
---------------------------

MUTUAL FUND

     Investments held in the Vanguard
     REIT Index Fund                                           2,750,713                         $         32,568
                                                                                                    ==============





                                     - 13 -



                                                                               Employer Identification # 36-3051915
                                                                               Plan #  020
                                                  AON SAVINGS PLAN
                           Schedule H, Line 4i - SCHEDULE OF ASSETS (HELD AT END OF YEAR)
                                                 December 31, 2002
                                                    (continued)

                                                             Number of Shares                      Current Value
                                                             ----------------
Identity of Issuer                                           Principal Amount                        (thousands)
------------------------------------------------------------------------------------------------------------------
                                                                                           
INVESCO DYNAMICS FUND
---------------------

MUTUAL FUND

     Investments held in the INVESCO
     Dynamics Fund*                                            1,512,539                         $         16,124
                                                                                                    ==============


DODGE & COX COMMON STOCK FUND
-----------------------------

MUTUAL FUND

     Investments held in the Dodge & Cox
     Common Stock Fund                                           575,601                         $         50,682
                                                                                                    ==============


PIMCO TOTAL RETURN FUND
-----------------------

MUTUAL FUND

     Investments held in the PIMCO
     Total Return Fund                                         2,980,263                         $         31,799
                                                                                                    ==============


MONTAG & CALDWELL GROWTH FUND
-----------------------------

MUTUAL FUND

     Investments held in the Montag & Caldwell
     Growth Fund                                                 405,268                         $          7,595
                                                                                                    ==============


MANAGERS SPECIAL EQUITY FUND
----------------------------

MUTUAL FUND

     Investments held in the Managers
     Special Equity Fund                                         248,109                         $         13,666
                                                                                                    ==============



                                     - 14 -



                                                                               Employer Identification # 36-3051915
                                                                               Plan #  020
                                                  AON SAVINGS PLAN
                           Schedule H, Line 4i - SCHEDULE OF ASSETS (HELD AT END OF YEAR)
                                                 December 31, 2002
                                                    (continued)

                                                             Number of Shares        Cost          Current Value
                                                             ----------------        ----
Identity of Issuer                                           Principal Amount     (thousands)       (thousands)
------------------------------------------------------------------------------------------------------------------
                                                                                           
TEMPLETON EMERGING MARKETS FUND
-------------------------------

MUTUAL FUND

     Investments held in the Templeton
     Emerging Markets Fund                                       359,995                         $          2,916
                                                                                                    ==============


VANGUARD ADMIRAL INTERMEDIATE TERM
----------------------------------
    TREASURY FUND
    -------------

MUTUAL FUND

     Investments held in the Vanguard Admiral
     Intermediate Term Treasury Fund                           7,275,535                         $         85,778
                                                                                                    ==============

INVESCO INTERNATIONAL EQUITY FUND
---------------------------------

COLLECTIVE TRUST

     Investments held in the INVESCO
     International Equity Fund*                                1,757,753                         $         28,247
                                                                                                    ==============

ESOP ALLOCATED  FUND
--------------------

COMMON STOCK

     Aon Corporation
     Common Stock, 1.00 par*                                   5,726,374     $        89,864     $        110,361
                                                                                =============       ==============

OTHER COMMON AND PREFERRED STOCKS AND MUTUAL FUNDS (SELF-MANAGED FUNDS)
-----------------------------------------------------------------------

BROKERAGE ACCOUNTS

     Investments held in other common and preferred
     stocks and mutual funds and other investments             4,916,865                         $          4,917
                                                                                                    ==============

    Investments held in Aon Corporation
    Common Stock*                                              9,913                             $            187
                                                                                                    ==============



                                     - 15 -



                                                                               Employer Identification # 36-3051915
                                                                               Plan #  020
                                                  AON SAVINGS PLAN
                           Schedule H, Line 4i - SCHEDULE OF ASSETS (HELD AT END OF YEAR)
                                                 December 31, 2002
                                                    (continued)

                                                             Number of Shares                      Current Value
                                                             ----------------
Identity of Issuer                                           Principal Amount                        (thousands)
------------------------------------------------------------------------------------------------------------------
                                                                                           
    Investment held in the State Street
    Short-Term Investment Fund                                 1,498,625                         $          1,499
                                                                                                    ==============


     PARTICIPANT LOANS (5.25%-10.5%)                                   -                         $         18,957
                                                                                                    ==============

                                                                                                 $      1,087,311
                                                                                                    ==============


    *Party in interest transaction not prohibited by ERISA.


                                     - 16 -