SECURITIES AND EXCHANGE COMMISSION
                             WASHINGTON, D.C. 20549

                                    FORM 10-Q

        X        QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d)
                     OF THE SECURITIES EXCHANGE ACT OF 1934

                FOR THE QUARTERLY PERIOD ENDED SEPTEMBER 30, 2001

                                       OR

        _        TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d)
                     OF THE SECURITIES EXCHANGE ACT OF 1934

                          Commission file number 1-7933

                                 Aon Corporation
                                 ---------------
             (Exact Name of Registrant as Specified in its Charter)

           DELAWARE                                       36-3051915
           --------                                       ----------
(State or Other Jurisdiction of                          (IRS Employer
Incorporation or Organization)                            Identification No.)



200 E. RANDOLPH ST., CHICAGO, ILLINOIS                        60601
- --------------------------------------                        -----
(Address of Principal Executive Offices)                      (Zip Code)

             (312) 381-1000
             --------------
     (Registrant's Telephone Number)


Indicate  by check  mark  whether  the  Registrant:  (1) has filed  all  reports
required to be filed by Section 13 or 15(d) of the  Securities  and Exchange Act
of 1934  during the  preceding  3 months (or for such  shorter  period  that the
Registrant was required to file such reports),  and (2) has been subject to such
filing requirements for the past 90 days. YES X NO
                                              -    -

Number of shares of common stock outstanding:

                                                    No. Outstanding
                Class                                as of 9-30-01
                -----                                -------------

        $1.00 par value Common                        269,217,702





                                     PART 1
                              Financial Information
                                 Aon CORPORATION
             Condensed Consolidated Statements of Financial Position




 (millions)                                                      AS OF            AS OF
                                                            SEPT. 30, 2001    DEC. 31, 2000
                                                            --------------------------------
 ASSETS                                                         (Unaudited)
                                                                             

 Investments

   Fixed maturities at fair value                                 $  2,336         $  2,337

   Equity securities at fair value                                     416              492

   Short-term investments                                            2,899            2,325

   Other investments                                                   736              865

                                                            ---------------  ---------------
       TOTAL INVESTMENTS                                             6,387            6,019


 CASH                                                                  498            1,118


 RECEIVABLES

   Insurance brokerage and consulting
        services                                                     7,143            6,952

   Premiums and other                                                1,210            1,278

                                                            ---------------  ---------------
       TOTAL RECEIVABLES                                             8,353            8,230


 EXCESS OF COST OVER NET ASSETS PURCHASED                            3,626            3,427


 OTHER INTANGIBLE ASSETS                                               469              489


 OTHER ASSETS                                                        3,512            2,968

                                                            ---------------  ---------------
       TOTAL ASSETS                                               $ 22,845         $ 22,251
                                                            ===============  ===============


                                                                 AS OF            AS OF
                                                            SEPT. 30, 2001    DEC. 31, 2000
                                                            --------------------------------
 LIABILITIES AND STOCKHOLDERS' EQUITY                           (Unaudited)

 INSURANCE PREMIUMS PAYABLE                                       $  8,722         $  8,212

 POLICY LIABILITIES
   Future policy benefits                                            1,088            1,054
   Policy and contract claims                                        1,078              801
   Unearned and advance premiums                                     2,041            1,935
   Other policyholder funds                                            827            1,069
                                                            ---------------  ---------------
       TOTAL POLICY LIABILITIES                                      5,034            4,859

 GENERAL LIABILITIES
   General expenses                                                  1,685            1,619
   Short-term borrowings                                               193              309
   Notes payable                                                     1,660            1,798
   Other liabilities                                                 1,075            1,216
                                                            ---------------  ---------------
       TOTAL LIABILITIES                                            18,369           18,013


 COMMITMENTS AND CONTINGENT LIABILITIES

 REDEEMABLE PREFERRED STOCK                                             50               50

 COMPANY-OBLIGATED MANDATORILY REDEEMABLE
   PREFERRED CAPITAL SECURITIES OF SUBSIDIARY
   TRUST HOLDING SOLELY THE COMPANY'S JUNIOR
   SUBORDINATED DEBENTURES                                             800              800


 STOCKHOLDERS' EQUITY
   Common stock - $1 par value                                         292              264
   Paid-in additional capital                                        1,650              706
   Accumulated other comprehensive loss                               (377)            (377)
   Retained earnings                                                 3,060            3,127
   Less - Treasury stock at cost                                      (807)            (118)
          Deferred compensation                                       (192)            (214)
                                                            ---------------  ---------------
       TOTAL STOCKHOLDERS' EQUITY                                    3,626            3,388

                                                            ---------------  ---------------
       TOTAL LIABILITIES AND STOCKHOLDERS' EQUITY                 $ 22,845         $ 22,251
                                                            ===============  ===============


See the accompanying notes to the condensed consolidated financial statements.

                                     - 1 -



                                                            AON CORPORATION
                                               Condensed Consolidated Statements of Income
                                                             (Unaudited)

                                                                         THIRD QUARTER ENDED              NINE MONTHS ENDED
                                                                     ----------------------------    ---------------------------
 (millions except per share data)                                      SEPT. 30,      SEPT. 30,        SEPT. 30,      SEPT. 30,
                                                                          2001           2000             2001           2000
                                                                     -------------  -------------    ------------- -------------
                                                                                                            
 REVENUE
    Brokerage commissions and fees .................................      $ 1,297        $ 1,176          $ 3,925       $ 3,584
    Premiums and other .............................................          510            476            1,510         1,435
    Investment income ..............................................          105            133              205           395
                                                                     -------------  -------------    ------------- -------------
       TOTAL REVENUE ...............................................        1,912          1,785            5,640         5,414
                                                                     -------------  -------------    ------------- -------------

 EXPENSES
    General expenses ...............................................        1,384          1,208            4,303         3,741
    Benefits to policyholders ......................................          271            257              823           766
    Interest expense ...............................................           31             38               98           102
    Amortization of intangible assets ..............................           40             38              118           115
    Unusual expenses - World Trade Center (see note 2) ..............           53              -               53             -
                                                                     -------------  -------------    ------------- -------------
       TOTAL EXPENSES. .............................................        1,779          1,541            5,395         4,724
                                                                     -------------  -------------    ------------- -------------

 INCOME BEFORE INCOME TAX, MINORITY INTEREST AND ACCOUNTING CHANGE .          133            244              245           690
    Provision for income tax .......................................           51             95               95           269
                                                                     -------------  -------------    ------------- -------------
 INCOME BEFORE MINORITY INTEREST AND ACCOUNTING CHANGE .............           82            149              150           421
    Minority interest - 8.205% trust preferred capital securities ..          (10)           (10)             (30)          (30)
                                                                     -------------  -------------    ------------- -------------
 INCOME BEFORE ACCOUNTING CHANGE ...................................           72            139              120           391
    Cumulative effect of change in accounting principle, net of tax             -              -                -            (7)
                                                                     -------------  -------------    ------------- -------------
 NET INCOME ........................................................      $    72        $   139          $   120       $   384
                                                                     =============  =============    ============= =============
    Preferred stock dividends ......................................           (1)            (1)              (2)           (2)
                                                                     -------------  -------------    ------------- -------------
 NET INCOME AVAILABLE FOR COMMON STOCKHOLDERS ......................      $    71        $   138          $   118       $   382
                                                                     =============  =============    ============= =============

 BASIC NET INCOME PER SHARE:
    Before accounting change .......................................      $  0.26        $  0.53          $  0.44       $  1.50
    Cumulative effect of change in accounting principle ............            -              -                -         (0.03)
                                                                     -------------  -------------    ------------- -------------
                Basic net income per share .........................      $  0.26        $  0.53          $  0.44       $  1.47
                                                                     =============  =============    ============= =============

 DILUTIVE NET INCOME PER SHARE:
    Before accounting change .......................................      $  0.26        $  0.53          $  0.44       $  1.49
    Cumulative effect of change in accounting principle ............            -              -                -         (0.03)
                                                                     -------------  -------------    ------------- -------------
                Dilutive net income per share ......................      $  0.26        $  0.53          $  0.44       $  1.46
                                                                     =============  =============    ============= =============

 CASH DIVIDENDS PER SHARE PAID ON COMMON STOCK .....................      $ 0.225        $  0.22          $  0.67       $  0.65
                                                                     =============  =============    ============= =============

 Dilutive average common and common equivalent shares outstanding ..        275.4          262.8            271.0         261.7
                                                                     =============  =============    ============= =============


See the accompanying notes to the condensed consolidated financial statements.

                                     - 2 -






                                                                AON CORPORATION
                                                CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS
                                                                  (UNAUDITED)

                                                                                               NINE MONTHS ENDED
                                                                                     --------------------------------------
                                                                                         SEPT. 30,            SEPT. 30,
 (millions)                                                                                2001                 2000
                                                                                     -----------------    -----------------

                                                                                                               
 CASH FLOWS FROM OPERATING ACTIVITIES:
   Net income ......................................................................            $ 120                $ 384
   Adjustments to reconcile net income to cash provided by operating activities
        Cumulative effect of change in accounting principle, net of tax ............                -                    7
        Insurance operating assets and liabilities net of reinsurance ..............               90                   32
        Amortization of intangible assets ..........................................              118                  115
        Depreciation and amortization of property, equipment and software ..........              134                  131
        Income taxes ...............................................................              (93)                 125
        Special charge and purchase accounting liabilities .........................               86                  (90)
        Valuation changes on investments, income on disposals and impairments ......              101                  (72)
        Other receivables and liabilities - net ....................................              122                  (98)
                                                                                     -----------------    -----------------
            CASH PROVIDED BY OPERATING ACTIVITIES ..................................              678                  534
                                                                                     -----------------    -----------------

 CASH FLOWS FROM INVESTING ACTIVITIES:
   Sale of investments
        Fixed maturities
            Maturities .............................................................               93                   86
            Calls and prepayments ..................................................               73                  106
            Sales ..................................................................              712                  218
        Equity securities ..........................................................              257                  173
        Other investments ..........................................................               93                  253
   Purchase of investments
        Fixed maturities ...........................................................             (817)                (298)
        Equity securities ..........................................................             (178)                (130)
        Other investments ..........................................................              (58)                (433)
   Purchase of short-term investments - net ........................................             (558)                (156)
   Acquisition of subsidiaries .....................................................             (101)                 (60)
   Property and equipment and other - net ..........................................             (166)                (104)
                                                                                     -----------------    -----------------
            CASH USED IN INVESTING ACTIVITIES ......................................             (650)                (345)
                                                                                     -----------------    -----------------

 CASH FLOWS FROM FINANCING ACTIVITIES:
    Treasury stock transactions - net ..............................................               30                  (61)
    Issuance (payments) of short-term borrowings - net .............................             (116)                 178
    Issuance of long-term debt .....................................................                -                  250
    Repayment of long-term debt ....................................................             (136)                 (26)
    Interest sensitive, annuity and investment-type contracts
        Deposits ...................................................................               20                   65
        Withdrawals ................................................................             (265)                (275)
    Cash dividends to stockholders .................................................             (179)                (168)
                                                                                     -----------------    -----------------
            CASH USED IN FINANCING ACTIVITIES ......................................             (646)                 (37)
                                                                                     -----------------    -----------------

 EFFECT OF EXCHANGE RATE CHANGES ON CASH ...........................................               (2)                  (9)
                                                                                     -----------------    -----------------
 INCREASE (DECREASE) IN CASH .......................................................             (620)                 143
 CASH AT BEGINNING OF PERIOD .......................................................            1,118                  837
                                                                                     -----------------    -----------------
 CASH AT END OF PERIOD .............................................................            $ 498                $ 980
                                                                                     =================    =================



 See the accompanying notes to condensed consolidated financial statements.

                                     - 3 -


NOTES TO THE CONDENSED CONSOLIDATED FINANCIAL STATEMENTS


1.       Statement of Accounting Principles
         ----------------------------------

         The financial  results included in this report are stated in conformity
         with accounting  principles generally accepted in the United States and
         are unaudited but include all normal  recurring  adjustments  which the
         Registrant  ("Aon") considers  necessary for a fair presentation of the
         results for such  periods.  These interim  figures are not  necessarily
         indicative of results for a full year as further discussed below.

         Refer to the consolidated  financial statements and notes in the Annual
         Report  to  Stockholders  for the  year  ended  December  31,  2000 for
         additional  details  of  Aon's  financial   position,   as  well  as  a
         description  of the  accounting  policies  which  have  been  continued
         without  material  change.  The details  included in the notes have not
         changed  except as a result of normal  transactions  in the interim and
         the events mentioned in the footnotes below.


2.       Impact of September 11, 2001 / World Trade Center
         -------------------------------------------------

         On  September  11,  2001,  the World Trade  Center was  destroyed.  Aon
         occupied space on several floors of one of the towers,  where employees
         from insurance brokerage, human resource consulting,  claims servicing,
         other  specialty  operations,  and accident,  health and life insurance
         underwriting  worked and where one of our new client  service  business
         units was located.  Most regrettably,  176 of the employees are missing
         and presumed  dead or have been  confirmed  as  deceased.  All of Aon's
         normal processing systems are up and running.

         Aon has incurred  through  September 30, 2001, $251 million of expenses
         (before  insurance  recoveries)  related  to this  event.  These  costs
         include  $192  million as a result of our  Combined  Insurance  Company
         subsidiaries  directly underwriting the life insurance coverage for the
         benefit of missing  employees,  and is partially  offset by reinsurance
         receivables  of  $147  million.  As to  approximately  $90  million  of
         reinsurance  receivables  under a Business  Travel and Accident  policy
         issued  by  Combined  Insurance  Company  of  America  to  cover  Aon's
         employees,  reinsurers  have  declined  liability  via a  letter  dated
         November 12, 2001,  to Combined.  Legal actions have been taken by both
         parties. Other costs incurred were $29 million of depreciable assets at
         book value  destroyed  and $30 million for  salaries  and  benefits for
         missing  employees  and other  costs.  Offsetting  these  expenses  are
         estimated  insurance  recoveries  of $51  million.  Further  costs  and
         insurance  recoveries  including  estimated  proceeds from our business
         interruption  policies,  are  expected  to  occur  over  the  next  few
         quarters.  In the third quarter 2001,  Aon has recorded a pretax charge
         of $53 million  ($32  million  after-tax  or $0.12 per diluted  share),
         which is net of estimated insurance recoveries of $198 million.


3.       Accounting and Disclosure Changes
         ---------------------------------

         In December 1999, the Securities and Exchange  Commission  (SEC) issued
         Staff  Accounting  Bulletin (SAB) No. 101, which provides  guidance for
         applying  generally  accepted  accounting  principles  relating  to the
         timing of revenue  recognition in financial  statements  filed with the
         SEC.  Effective  January 1, 2000, in accordance  with the provisions of
         SAB 101, Aon established a provision for estimated returned commissions
         from policy  cancellations.  In 1999 and previous years, Aon recognized
         returned commissions when they occurred.  The cumulative effect of this
         accounting  change was an  after-tax  charge of $7 million or $0.03 per
         share in the first quarter of 2000.

                                     - 4 -

         In September  2000,  the Financial  Accounting  Standards  Board (FASB)
         issued  Statement  No. 140,  Accounting  for Transfers and Servicing of
         Financial Assets and Extinguishments of Liabilities.  Statement No. 140
         replaces Statement No. 125 and revises the standards for accounting for
         securitizations  and other transfers of financial assets and collateral
         and requires  certain  disclosures.  Statement No. 140 became effective
         for all transfers of financial  assets  occurring after March 31, 2001.
         Implementation  of Statement No. 140 did not have a material  impact on
         the consolidated financial statements.

         In July 2001, the FASB issued Statement No. 141, Business Combinations,
         and Statement No. 142, Goodwill and Other Intangible Assets.  Statement
         No. 141 supercedes  Accounting  Principles  Board (APB) Opinion No. 16,
         and amends or  supercedes  a number of  interpretations  of APB No. 16.
         Certain purchase  accounting guidance in APB No. 16, as well as certain
         of its amendments and  interpretations,  have been carried forward. The
         statement  eliminates the pooling of interests method of accounting for
         business  combinations.  It also  changes  the  criteria  to  recognize
         intangible  assets apart from goodwill.  The  requirements of Statement
         No. 141 are effective for any business combination accounted for by the
         purchase  method that is completed  after June 30, 2001.  Statement No.
         142  supercedes  APB  No.  17.  Under  this  statement,   goodwill  and
         indefinite  lived  intangible  assets are no longer  amortized  but are
         reviewed annually,  or more frequently if impairment  indicators arise,
         for impairment. Separable intangible assets that have finite lives will
         continue to be amortized  over their  useful  lives.  The  amortization
         provisions of Statement No. 142 apply to goodwill and intangible assets
         acquired after June 30, 2001.  With respect to goodwill  acquired prior
         to July 1, 2001,  amortization  will be  discontinued  effective  as of
         January 1, 2002. The full impact of applying these statements is yet to
         be  determined.  However,  reported  earnings  for Aon are  expected to
         increase by approximately  $120 million pre-tax on an annualized basis
         beginning in 2002.

         In August 2001, the FASB issued  Statement No. 144,  Accounting for the
         Impairment  or  Disposal  of  Long-Lived  Assets.   Statement  No.  144
         supercedes   Statement  No.  121,  Accounting  for  the  Impairment  of
         Long-Lived  Assets and for  Long-Lived  Assets to Be  Disposed  Of, and
         provides new rules on asset  impairment and a single  accounting  model
         for long-lived assets to be disposed of. Although retaining many of the
         fundamental  recognition  and  measurement  provisions of Statement No.
         121, the new rules significantly change the criteria that would have to
         be met to  classify  an  asset as  held-for-sale.  The new  rules  also
         supersede the  provisions  of APB Opinion 30,  Reporting the Results of
         Operations  -  Reporting  the  Effects  of  Disposal  of a Segment of a
         Business, and Extraordinary,  Unusual and Infrequently Occurring Events
         and Transactions, with regard to reporting the effects of a disposal of
         a segment of a business and require  expected future  operating  losses
         from discontinued operations to be displayed in discontinued operations
         in the period(s) in which the losses are incurred. Statement No. 144 is
         effective  January 1, 2002. Aon has not yet  determined the effect,  if
         any, this statement will have on the consolidated financial statements.


4.       Spin-Off of Underwriting Business
         ---------------------------------

         On April 20, 2001, Aon's Board of Directors approved,  in principle,  a
         plan to spin-off  its  current  underwriting  business to Aon's  common
         stockholders, creating two independent,  publicly-traded companies. The
         spin-off  would take the form of a  tax-free  stock  dividend  to Aon's
         common stockholders, pending a favorable Internal Revenue Service (IRS)
         ruling. The transaction is subject to final Board approval, a favorable
         IRS ruling, and certain insurance  regulatory  approvals.  The spin-off
         company  will  be  named  Combined  Specialty  Corporation  (CSC).  The
         spin-off is  currently  expected to be  completed  by Spring  2002.  In
         October 2001, Aon announced that it will

                                     - 5 -

         be expanding  its  insurance  underwriting  business to include  direct
         property and casualty  insurance  and  reinsurance  through its planned
         spin-off of CSC.


5.       Comprehensive Income
         --------------------

         The  components of  comprehensive  income,  net of related tax, for the
         third quarter and nine months ended  September 30, 2001 and 2000 are as
         follows:


                                                             Third Quarter Ended                          Nine Months Ended
                                                             -------------------                          -----------------
        (millions)                                      Sept. 30, 2001     Sept. 30, 2000          Sept. 30, 2001     Sept. 30, 2000
                                                        --------------     --------------          --------------     --------------

                                                                                                            
        Net income                                        $       72          $     139               $      120         $    384

        Net derivative gains (losses)                              7                  -                       (5)               -

        Net unrealized investment gains                           13                 16                       35               11

        Net foreign exchange gains
           (losses)                                               16                (31)                     (30)            (111)

                                                        --------------     --------------          --------------     --------------
        Comprehensive income                              $      108          $     124               $      120         $    284
                                                        ==============     ==============          ==============     ==============



         The components of accumulated other  comprehensive loss, net of related
         tax, at September 30, 2001 and December 31, 2000, are as follows:



        (millions)                                                      September 30, 2001           December 31, 2000
                                                                        ------------------           -----------------

                                                                                                       
        Net derivative gains                                                $        1                  $        6
        Net unrealized investment losses                                           (37)                        (72)
        Net foreign exchange losses                                               (297)                       (267)
        Net additional minimum pension liability                                   (44)                        (44)
                                                                            -----------                 -----------
        Accumulated other comprehensive loss                                $      (377)                $     (377)
                                                                            ============                ===========


6.       Business Segments
         -----------------

         Aon classifies its businesses  into three  operating  segments based on
         the types of services and/or products delivered. There is also a fourth
         non-operating segment, Corporate and Other. The Insurance Brokerage and
         Other Services segment consists primarily of Aon's retail,  reinsurance
         and  wholesale  brokerage  operations,  as  well  as  managing  general
         underwriting,   actuarial,  loss  control,  claims,   alternative  risk
         transfer and premium  financing  services.  Certain service  businesses
         related to insurance underwriting operations are also reflected in this
         segment.  The  Consulting  segment is Aon's  human  capital  consulting
         organization  which utilizes four practice groups:  employee  benefits,
         compensation,    management   consulting   and   employment   practices
         outsourcing.   The  Insurance  Underwriting  segment  is  comprised  of
         accident,   health  and  life  coverages,  and  extended  warranty  and
         specialty property and casualty insurance products. Corporate and Other
         segment  revenues  consist  primarily of investment  income from equity
         investments that are assets primarily of the underwriting subsidiaries.
         Revenues are derived from  valuation  changes in limited  partnerships,
         investment  income  from  certain  other  investments   (which  include
         non-income  producing  equities)  and income and losses on disposals of
         all securities,  including those pertaining to assets maintained by the
         operating  segments.  Corporate  and  Other  expenses  include  general
         expenses,  administrative  and certain  information  technology  costs,
         interest expense and goodwill amortization.

                                     - 6 -

         Amounts reported in the tables for the four segments,  when aggregated,
         total  to  the  amounts  in  the  accompanying  condensed  consolidated
         financial statements. Revenues are attributed to geographic areas based
         on the location of the resources  producing the revenues.  There are no
         material inter-segment amounts to be eliminated.

         Selected information reflecting Aon's operating segments follows.



  Third Quarter ended Sept.30:                  Insurance Brokerage                                               Insurance
  (millions)                                     and Other Services                 Consulting                  Underwriting
                                                 ------------------                 ----------                  ------------
                                                  2001          2000            2001         2000             2001         2000
                                                  ----          ----            ----         ----             ----         ----
                                                                                                       
  Revenue
     United States                              $   597       $   549          $ 161         $ 118           $ 409        $  384
     United Kingdom                                 227           231             37            35              75            74
     Continent of Europe                            149           134             15            13              30            25
     Rest of World                                  139           128             19            16              51            53
  ---------------------------------------------------------------------------------------------------------------------------------
  Total revenue                                 $ 1,112       $ 1,042          $ 232         $ 182           $ 565        $  536
  ---------------------------------------------------------------------------------------------------------------------------------
  Income before income taxes
     excluding unusual charges                  $   153       $   183          $  29         $  26           $  80        $    81
  Unusual charges - World Trade
      Center                                          8             -              -             -              45              -
  ---------------------------------------------------------------------------------------------------------------------------------
  Income before income taxes                    $   145       $   183          $  29         $  26           $  35        $    81
  ---------------------------------------------------------------------------------------------------------------------------------





Nine Months ended Sept. 30:                      Insurance Brokerage                                             Insurance
(millions)                                       and Other Services                 Consulting                 Underwriting
                                                 ------------------                 ----------                 ------------
                                                 2001           2000             2001         2000           2001         2000
                                                 ----           ----             ----         ----           ----         ----
                                                                                                      
Revenue
   United States                               $ 1,740        $  1,618         $  453       $  326          $ 1,208      $ 1,154
   United Kingdom                                  670             673            110          114              225          233
   Continent of Europe                             550             503             53           49               91           79
   Rest of World                                   423             387             57           49              156          152
- ----------------------------------------------------------------------------------------------------------------------------------
Total revenue                                  $ 3,383        $  3,181         $  673       $  538          $ 1,680      $ 1,618
- ----------------------------------------------------------------------------------------------------------------------------------
Income before taxes excluding
   unusual and special charges                 $   544        $    545         $   84       $   68          $   227      $   227
Unusual charges - World Trade
    Center                                           8               -              -            -               45            -
Special charges                                    187               -              7            -               24            -
- ----------------------------------------------------------------------------------------------------------------------------------
Income before income taxes                     $   349        $    545         $   77       $   68          $   158      $   227
- ----------------------------------------------------------------------------------------------------------------------------------


                                     - 7 -


Selected information for Aon's non-operating segment follows:



Corporate and Other                                      Third Quarter ended Sept. 30,            Nine Months ended Sept. 30,
                                                      -------------------------------------    -----------------------------------
(millions)                                                  2001               2000                 2001              2000
- ----------------------------------------------------------------------------------------------------------------------------------

                                                                                                      
Corporate and other revenue:
Change in valuation on private limited
    partnership investments                             $        7         $      15            $    (56)         $       75
Income from marketable equity securities
     and other investments                                       2                 2                   6                   6
                                                      ------------------ ------------------    ---------------- ------------------
Corporate and other revenue before gain
    (loss ) on disposals and related expenses                    9                17                 (50)                 81
Gain (loss) on disposals and related
     expenses*                                                  (6)                8                 (46)                 (4)
- ----------------------------------------------------------------------------------------------------------------------------------
Corporate and other revenue                            $         3         $      25            $    (96)         $       77
- ----------------------------------------------------------------------------------------------------------------------------------

Non-operating expenses:
   Amortization of goodwill                            $        30         $      29            $     88          $       85
   Interest expense                                             31                38                  98                 102
   General expenses                                             18                 4                  57                  40
- ----------------------------------------------------------------------------------------------------------------------------------
Loss before income taxes                               $       (76)        $     (46)           $   (339)         $     (150)
- ----------------------------------------------------------------------------------------------------------------------------------
<FN>
* Nine months 2001 includes impairment write-downs of $29 million.
</FN>



7.       Capital Stock
         -------------

         During the first nine months of 2001, Aon reissued  2,629,000 shares of
         common  stock from  treasury  for  employee  benefit  plans and 519,300
         shares in connection with the employee stock purchase plan.  During the
         first nine months of 2001,  Aon acquired  137,000  shares of its common
         stock at a total value of $4.7 million and obtained  approximately 22.4
         million  shares  of stock in  connection  with the  acquisition  of two
         entities  controlled by Aon's Chairman and Chief Executive Officer (see
         footnote  14).  The  acquisition  was  financed by the issuance of 22.4
         million new shares of Aon common  stock.  The  additional  22.4 million
         shares of treasury stock are restricted as to their  reissuance.  There
         were 23.1 million  shares of common stock held in treasury at September
         30, 2001.


8.       Capital Securities
         ------------------

         In 1997, Aon Capital A, a subsidiary  trust of Aon, issued $800 million
         of 8.205% mandatorily  redeemable preferred capital securities (capital
         securities).  The sole asset of Aon Capital A is $824 million aggregate
         principal  amount  of  Aon's  8.205%  Junior  Subordinated   Deferrable
         Interest Debentures due January 1, 2027.

                                     - 8 -


9.       Business Combinations
         ---------------------

         For the third quarter and nine months of 2001,  Aon made payments of $4
         million and $12 million,  respectively,  on  restructuring  charges and
         purchase accounting liabilities relating to business combinations.

         In 1996 and 1997, Aon recorded  pretax  special  charges of $60 million
         and $145 million, respectively, related to management's commitment to a
         formal plan of restructuring Aon's brokerage  operations as a result of
         the acquisition of Alexander & Alexander Services,  Inc. (A&A). Also in
         1997,   following   management's   commitment   to  a  formal  plan  of
         restructuring the A&A and Bain Hogg brokerage operations,  Aon recorded
         $264 million in costs to restructure those acquisitions.  These charges
         primarily  related  to  termination  benefits  of $152  million,  lease
         abandonments   and  other  exit  costs  of  $280  million,   and  asset
         impairments of $37 million.  As of December 31, 2000,  all  termination
         benefits have been paid. The remaining  liability of $68 million is for
         lease abandonments and other exit costs.

         The following table  demonstrates  recent activity  regarding the lease
         abandonments and other exit costs associated with the A&A and Bain Hogg
         acquisitions:



                  (millions)                                                    Lease Abandonments and Other
                                                                                         Exit Costs
                                                                              ----------------------------------
                                                                                
                  Balance at December 31, 1998                                           $        155
                  Cash payments in 1999 and 2000                                                  (77)
                  Charge to expense in 1999 and 2000                                                6
                  Cash payments in 2001                                                           (10)
                  Foreign currency revaluation                                                     (6)
                                                                                         -------------
                  Balance at September 30, 2001                                          $         68
                                                                                         =============


         The combination of 1998  acquisitions  and the finalization of purchase
         accounting  for the 1997 Jauch & Hubener  acquisition  resulted  in $70
         million of purchase accounting  liabilities.  In 1999, a charge of $120
         million was recorded for a plan to  restructure  Aon's  operations as a
         result  of  business  combination  activity.  These  charges  primarily
         related to termination  benefits of $107 million,  the related  pension
         expense of $32 million,  lease abandonments and other exit costs of $41
         million, and asset impairments of $10 million. As of September 30, 2001
         these  liabilities  have been  reduced to  termination  benefits  of $3
         million and lease abandonments of $3 million.

         All of Aon's unpaid liabilities  relating to acquisitions are reflected
         in general expense liabilities in the condensed consolidated statements
         of financial position.


10.      Business Transformation Plan
         ----------------------------

         In fourth quarter 2000, Aon commenced a business  transformation  plan.
         This plan has been  implemented  during the fourth  quarter of 2000 and
         the  first  nine  months  of 2001  and  will  continue  throughout  the
         remainder of 2001 and into 2002. Pretax special charges of $82 million,
         $72 million and $146 million were recorded in fourth  quarter 2000, and
         the first and second quarters of 2001,  respectively,  and are recorded
         in general expenses in the condensed consolidated statements of income.
         For the first nine months of 2001,  charges  included  costs related to
         termination  benefits of $109 million,  other costs to exit an activity
         of $21 million and other charges of $89 million  primarily

                                     - 9 -

         relating to costs for the  abandonment of systems and equipment as well
         as to end Aon's  involvement  in certain  joint  ventures  and  service
         partner relationships that did not meet profitability hurdles.

         Approximately  4,000  employees have been notified that their positions
         have  been or will be  eliminated  under the  plan.  Most have  already
         departed  Aon.  Most of these  positions  were related to the Insurance
         Brokerage and Other Services segment in the U.S. and the U.K.

         For the third quarter and first nine months of 2001,  Aon made payments
         of $31 million and $80 million,  respectively,  related to the business
         transformation plan.

         The following  demonstrates  the activity  related to the liability for
         termination  benefits  and  other  costs  to exit an  activity  for the
         business transformation plan.



                                                                                              Other Costs
                                                                        Termination            to Exit an
           (millions)                                                      Benefits              Activity           Total
           --------------------------------------------------------------------------------------------------------------------

                                                                                                        
           Expense charged in 2000                                     $       54             $        6         $      60
           Cash payments in 2000                                              (13)                    (3)              (16)
           Expense charged in 2001                                            109                     21               130
           Cash payments in 2001                                              (58)                   (22)              (80)
           --------------------------------------------------------------------------------------------------------------------
           Balance at September 30, 2001                               $       92             $        2         $      94
           --------------------------------------------------------------------------------------------------------------------


         All of Aon's unpaid liabilities relating to the business transformation
         plan are  reflected in general  expense  liabilities  in the  condensed
         consolidated statements of financial position.


11.      Income Per Share
         ----------------

         Income per share is calculated as follows:



                                                        Third Quarter ended Sept. 30,          Nine Months ended Sept. 30,
                                                        -----------------------------          ---------------------------
    (millions)                                             2001               2000                2001               2000
    ------------------------------------------------   ------------       -------------       -------------      ------------

                                                                                                     
    Net income                                           $      72          $     139           $     120           $     384
    Redeemable preferred stock dividends                        (1)                (1)                 (2)                 (2)
                                                       ------------       -------------        ------------      -------------
    Net income for dilutive and basic                    $      71          $     138           $     118           $     382
                                                       ============       =============        ============      =============

    Basic shares outstanding                                   272                260                 268                 259
    Common stock equivalents                                     3                  3                   3                   3
                                                       ------------       -------------        ------------      -------------
    Dilutive potential common shares                           275                263                 271                 262
    ---------------------------------------            ------------       -------------        ------------      -------------
    Basic net income per share                          $    0.26           $    0.53           $    0.44           $    1.47
    Dilutive net income per share                       $    0.26           $    0.53           $    0.44           $    1.46
    ---------------------------------------            ------------       -------------        ------------      -------------


                                     - 10 -


12.      Alexander & Alexander Services Inc. (A&A) Discontinued Operations
         -----------------------------------------------------------------

         A&A  discontinued  its  property and  casualty  insurance  underwriting
         operations in 1985,  some of which were then placed into run-off,  with
         the  remainder  sold in 1987.  In  connection  with  those  sales,  A&A
         provided  indemnities  to the  purchasers  for  various  estimated  and
         potential  liabilities,  including  provisions  to cover future  losses
         attributable to insurance pooling arrangements, a stop-loss reinsurance
         agreement,  and actions or omissions by various  underwriting  agencies
         previously managed by an A&A subsidiary.  As of September 30, 2001, the
         liabilities  associated with the foregoing  indemnities and liabilities
         of insurance  underwriting  subsidiaries  that are currently in run-off
         were  included  in  other  liabilities  in the  accompanying  condensed
         consolidated   statements  of  financial  position.   Such  liabilities
         amounted to $117 million,  net of  reinsurance  recoverables  and other
         assets  of $152  million,  and  would  be  substantially  reduced  if a
         February,  2000 ruling from the Court of Appeal in England favorable to
         A&A, in respect of which right to appeal has been granted,  were upheld
         in a decision expected in or around 2002.


13.      Contingencies
         -------------

         Aon  and  its  subsidiaries   are  subject  to  numerous  claims,   tax
         assessments and lawsuits that arise in the ordinary course of business.
         The damages  that may be claimed  are  substantial,  including  in many
         instances  claims for punitive or extraordinary  damages.  Accruals for
         these  items have been  provided  to the extent  that losses are deemed
         probable and are estimable.

         In 1998, the Internal Revenue Service (IRS) proposed adjustments to the
         tax of certain Aon  subsidiaries  for the period of 1990 through  1993.
         Most  of  these   adjustments   should  be  resolved   through  factual
         substantiation  of certain  accounting  matters.  However,  the IRS has
         contended  that  retro-rated   extended   warranty   contracts  do  not
         constitute  insurance  for  tax  purposes.  Accordingly,  the  IRS  has
         proposed  a  deferral  of  deductions  for   obligations   under  those
         contracts. The effect of such deferral would be to increase the current
         tax  obligations  of certain  Aon  subsidiaries  by  approximately  $74
         million,  $3 million,  $5 million and $12 million  (plus  interest)  in
         years 1990, 1991, 1992, and 1993,  respectively.  Aon believes that the
         IRS's position is without merit and inconsistent with numerous previous
         IRS private letter rulings. Aon has commenced an administrative  appeal
         and intends to contest vigorously such treatment.  Aon believes that if
         the contracts  are deemed not to be insurance  for tax  purposes,  they
         would be recharacterized in such a way that the increased taxes for the
         years in question would be far less than the proposed assessments.

         In the second quarter of 1999,  Allianz Life Insurance Company of North
         America,  Inc.  ("Allianz")  filed an amended  complaint  in  Minnesota
         adding a brokerage  subsidiary of Aon as a defendant in an action which
         Allianz brought against three insurance  carriers reinsured by Allianz.
         These three carriers  provided  certain types of workers'  compensation
         reinsurance to a pool of insurers and to certain  facilities managed by
         Unicover  Managers,  Inc.  ("Unicover"),  a New Jersey  corporation not
         affiliated with Aon.  Allianz alleges that the Aon subsidiary  acted as
         an agent of the three  carriers  when placing  reinsurance  coverage on
         their behalf.  Allianz claims that the  reinsurance it issued should be
         rescinded  or that it  should  be  awarded  damages,  based on  alleged
         fraudulent,  negligent and innocent misrepresentations by the carriers,
         through  their  agents,  including the Aon  subsidiary  defendant.  Aon
         believes that the Aon subsidiary has  meritorious  defenses and the Aon
         subsidiary intends to vigorously defend this claim.

                                     - 11 -


         Except for an action  filed to compel Aon to produce  documents,  which
         has  been  settled,   the  Allianz  lawsuit  is  the  only  lawsuit  or
         arbitration  relating to Unicover  in which any  Aon-related  entity is
         currently a party.

         Certain U.K. subsidiaries of Aon have been required by their regulatory
         body, the Personal  Investment  Authority (PIA), to review advice given
         by those  subsidiaries  to individuals  who bought pension plans during
         the period from April 1988 to June 1994. These reviews have resulted in
         a requirement to pay compensation to clients based on guidelines issued
         by the PIA.  Aon's  ultimate  exposure  from the private  pension  plan
         review,  as  presently  calculated,  is subject to a number of variable
         factors including, among others, general level of pricing in the equity
         markets,  the  interest  rate  established  quarterly  for  calculating
         compensation,  and the precise scope,  duration and  methodology of the
         review,  including whether recent  regulatory  guidance will have to be
         applied to previously settled claims.

         As to  approximately  $90 million of  reinsurance  receivables  under a
         Business  Travel  and  Accident  policy  issued by  Combined  Insurance
         Company of America to cover Aon's  employees,  reinsurers have declined
         liability  via a letter dated  November 12,  2001,  to Combined.  Legal
         actions have been filed by both parties.

         Although the ultimate  outcome of all matters  referred to above cannot
         be ascertained and liabilities in indeterminate  amounts may be imposed
         on Aon or  its  subsidiaries,  on the  basis  of  present  information,
         amounts already provided, availability of insurance coverages and legal
         advice  received,  it is the opinion of management that the disposition
         or  ultimate  determination  of such  claims  will not have a  material
         adverse effect on the consolidated  financial position of Aon. However,
         it is possible that future  results of operations or cash flows for any
         particular  quarterly or annual period could be materially  affected by
         an unfavorable resolution of these matters.


14.      Acquisitions
         ------------

         Acquisitions  which  closed  in July  2001  were  disclosed  in Part I,
         Footnote  13 and 14 of  Aon's  Quarterly  Report  on  Form  10Q for the
         quarter ended June 30, 2001 and are incorporated herein by reference.


15.      Subsequent Event
         ----------------

         On November 7, 2001, Aon announced that, together with Zurich Financial
         Services,  Aon will be  sponsoring a new  Bermuda-based  insurance  and
         reinsurance  company to provide  much needed  underwriting  capacity to
         commercial property and casualty insurance and reinsurance clients. The
         new company will be named Endurance  Specialty Insurance Ltd. Plans for
         the new company include  capitalization  of approximately  $1.2 billion
         with  investments from several parties,  including  approximately  $200
         million by Aon.  Funding of this  investment  is  intended to come from
         Aon's  underwriting  subsidiaries and is available from operating cash.
         It is  anticipated  that,  after the  planned  spin-off of CSC from Aon
         Corporation (see footnote 4), CSC will be a minority owner in Endurance
         Specialty.

         As to  approximately  $90 million of  reinsurance  receivables  under a
         Business  Travel  and  Accident  policy  issued by  Combined  Insurance
         Company of America to cover Aon's  employees,  reinsurers have declined
         liability  via a letter dated  November 12,  2001,  to Combined.  Legal
         actions have been filed by both parties.

                                     - 12 -


                                 AON CORPORATION
                      MANAGEMENT'S DISCUSSION AND ANALYSIS
                OF FINANCIAL CONDITION AND RESULTS OF OPERATIONS

                     THIRD QUARTER ENDED SEPTEMBER 30, 2001


GENERAL
- -------

Aon has three  operating  segments:  Insurance  Brokerage  and  Other  Services,
Consulting and Insurance  Underwriting.  These segments are based on the type of
client and the services or products delivered.  Aon has a fourth,  non-operating
segment, Corporate and Other.

References  to  organic  revenue  growth  exclude  the  impact of  acquisitions,
dispositions,  transfers,  investment income, foreign exchange and other unusual
items. Within the Insurance Underwriting segment, written premiums are the basis
for the  measurement of organic  growth.  References to income before income tax
are before  minority  interest  related to the  issuance  of 8.205%  mandatorily
redeemable preferred capital securities and the cumulative effect of a change in
accounting principle. For purposes of operating segment discussions, comparisons
against 2000 results exclude unusual and special charges.

INFORMATION CONCERNING FORWARD-LOOKING STATEMENTS
- -------------------------------------------------

This quarterly report may contain certain statements relating to future results,
which are  forward-looking  statements  as that term is defined  in the  Private
Securities Litigation Reform Act of 1995. These  forward-looking  statements are
subject to certain risks and  uncertainties  that could cause actual  results to
differ materially from either historical or anticipated results,  depending on a
variety of factors.  Potential  factors  that could impact  results  include the
general   economic   conditions  in  different   countries   around  the  world,
fluctuations  in global equity and fixed income  markets,  changes in commercial
property and casualty  premium rates,  the competitive  environment,  the actual
cost of  resolution of  contingent  liabilities,  the final form of the business
transformation plan, the ultimate cost and timing of the implementation thereof,
the actual cost  savings and other  benefits  resulting  therefrom,  whether the
Company  ultimately   implements  the  proposed  spin-off  of  its  underwriting
operations,   and  the  timing  and  terms  associated  therewith,   and  events
surrounding  terrorist attacks of September 11, 2001,  including the timing and
resolution of related insurance and reinsurance issues.

SPIN-OFF OF UNDERWRITING BUSINESS
- ---------------------------------

As previously  disclosed,  on April 20, 2001, Aon's Board of Directors approved,
in  principle,  a plan to spin-off  its  underwriting  business to Aon's  common
stockholders,  creating two independent, publicly traded companies. The spin-off
would take the form of a tax-free stock  dividend to Aon's common  stockholders.
The transaction is subject to final Board approval, a favorable Internal Revenue
Service ruling, and certain insurance regulatory approvals. In October 2001, Aon
announced plans to expand its underwriting operations to include direct property
and casualty insurance and reinsurance  policies to meet clients' growing demand
for insurance coverage. These expanded operations are intended to be part of the
spin-off and may require the raising of additional  capital.  In November  2001,
Aon  announced  that  it  would  sponsor  a  new,  Bermuda-based  insurance  and
reinsurance company to provide underwriting  capacity to commercial property and
casualty  insurance and reinsurance  clients.  It is anticipated  that after the
spin-off of CSC, CSC will be a minority owner of this company.  The  transaction
is subject to final Board approval, a favorable Internal Revenue Service ruling,
and certain insurance regulatory approvals.

                                     - 13 -


WORLD TRADE CENTER
- ------------------

On September 11, 2001, the World Trade Center was destroyed.  Aon occupied space
on  several  floors  of  one of  the  towers,  where  employees  from  insurance
brokerage,   human  resource  consulting,   claims  servicing,  other  specialty
operations,  and accident,  health and life insurance underwriting worked. Most
regrettably, 176 of the employees are missing and either presumed  dead or have
been confirmed as deceased.

The  events  of  September  11 are  expected  to have an  unfavorable  impact on
near-term  financial  results  due in part to the loss of many  highly  talented
employees.   Other  factors  include  delayed  billings  resulting  from  policy
extensions  arranged  for  clients,  building  closures,  business  interruption
issues,  and benefits to families of deceased  employees.  The exact impact that
Aon will experience from these events is not currently  determinable  and future
insurance claims may act to offset some of these costs.

World Trade Center costs  identified thus far for inclusion in the third quarter
results total $53 million on a pre-tax  basis.  These  expenses are  principally
composed of life insurance  benefits of $45 million,  net of approximately  $147
million of reinsurance recoveries, provided under life insurance policies issued
by Aon's  Combined  Insurance  Company  subsidiaries  for Aon  employees.  As to
approximately $90 million of reinsurance receivables under a Business Travel and
Accident policy issued by Combined  Insurance  Company of America to cover Aon's
employees,  reinsurers  have declined  liability via a letter dated November 12,
2001, to Combined. Legal actions have been filed by both parties.  Expenses also
included $30 million for salaries and benefits for missing  employees  and other
costs and $29 million of depreciable  assets at book value which were destroyed,
offset by estimated insurance recoveries of $51 million.

Additional  costs  are  expected  to be  incurred  in the  fourth  quarter,  and
potentially into 2002. Currently, some known costs have been incurred and offset
by insurance  claims and many costs and  recoveries  remain to be identified and
quantified, including business interruption issues, current replacement value of
lost assets and other related  issues.  As our analysis of the issues  continues
into the fourth  quarter  and  additional  insurance  claims are  presented,  an
accounting gain could potentially be recognized in the fourth quarter 2001 or in
2002.


BUSINESS TRANSFORMATION PLAN
- ----------------------------

In November 2000,  Aon's Board of Directors  approved a  comprehensive  business
transformation  plan designed to enhance client service,  significantly  improve
the way Aon conducts  business,  improve  profitability  through  utilization of
technology and process redesign, and accelerate organic revenue growth.

Implementation of the business  transformation plan began in fourth quarter 2000
and will continue throughout 2001 and into 2002. Total plan costs, which include
transition expenses,  were originally expected to be less than $325 million on a
pretax  basis.  The  majority  of the plan costs and  savings are related to the
Insurance Brokerage and Other Services segment,  principally in the U.S. and the
United Kingdom, where most of Aon's offices and employees are located.  Slightly
more than half of the total charges involve cash outlays for severance  payments
related to job eliminations. The net reductions of approximately 3,000 positions
are in line with previous  announcements  after  considering new hires resulting
from Aon's  evaluation  of work  processes,  changing job  functions and service
center locations.

                                     - 14 -


In the U.S.  retail  brokerage unit, the business  transformation  plan entailed
process redesign following the rollout of a new policy management and accounting
system, job redesign based on functional  expertise and the creation of four new
client service business units (CSBUs). During the second quarter, implementation
steps taken included notifications of job eliminations,  hiring of new employees
at new job grades and locations,  the creation of specialized syndication groups
to handle the  placement of insurance  coverage  with  insurance  carriers,  the
establishment of new business  development and relationship  management  groups,
and the building of the four CSBUs.

However,  conversions  of client  account  servicing  into the CSBUs fell behind
schedule due to unexpected  challenges in handling  higher  volumes of transfers
between  field  operations  and the CSBUs and steps were  taken to  improve  the
conversion process. These delays not only increased costs in the short-term, but
also put pressure on regional  offices that had to maintain  parallel systems to
ensure  quality  client  services.  This also  adversely  affected  new business
production in the U.S. in the quarter as attention was diverted from  generating
new accounts to completing client conversions.

Aon's  largest and most  advanced  CSBU was  located in the World Trade  Center,
which was  destroyed on  September  11,  2001.  This CSBU has been  relocated to
mid-town  Manhattan  in New York City,  along with a majority of the World Trade
Center retail brokerage employees. A concerted effort is currently being made to
fully convert client servicing for U.S. retail brokerage  accounts to the CSBU's
by second  quarter 2002,  which will involve  unplanned,  one-time  costs in the
fourth  quarter  2001 and the first half of 2002.  Total  costs  including  both
special charges and transition costs related to the business transformation plan
will therefore exceed the $325 million upper range originally projected. Some of
these costs, however, may be recoverable as part of our insurance claims.

In connection with the plan, Aon recorded pretax special charges of $218 million
($133 million after tax or $0.49 per share) for the first nine months 2001.  Aon
does  not  anticipate  any   additional   special   charges  from  the  business
transformation  plan.  Year-to-date,  charges of $108  million  were taken which
related to termination  benefits and involved about 3,200 employees.  As part of
the business transformation,  Aon examined its marginal return non-core business
alliances  and took a pretax charge of $50 million to end Aon's  involvement  in
certain  joint  ventures  and service  partner  relationships  that did not meet
profitability hurdles. It also allowed Aon to further reduce headcounts. Charges
of $60 million were incurred for asset  impairments,  primarily  relating to the
abandonment  of systems and  equipment,  and other  charges.  Transition  costs,
primarily  related to our core  operating  businesses,  were  approximately  $13
million in the third  quarter and $18 million for the first nine months 2001 and
consisted of system conversion costs,  consulting fees and employee compensation
and benefits.

Annualized  pretax savings from the plan are estimated to be approximately  $150
million to $200  million and are  expected to be achieved in 2002 as  transition
and  other  one-time  costs  related  to the  business  transformation  plan are
eliminated.  Savings  generated to date in 2001 were offset by transition  costs
and lower revenues.  As Aon progresses  through the next several quarters,  more
business  process change and additional  position  eliminations  will drive cost
savings.  Temporary  revenue  growth rate declines,  particularly  in Aon's U.S.
retail  brokerage  operation,  occurred  related to the  transformation  and may
continue to occur during the remainder of the plan's implementation.

                                     - 15 -


CONSOLIDATED RESULTS
- --------------------

Total revenue  increased $127 million or 7% when compared to third quarter 2000.
Excluding  the effect of foreign  exchange  rates,  revenues  rose 9% over third
quarter 2000,  attributable to growth in brokerage  commissions and fees,  which
was partially offset by a decline in investment income. Consolidated revenue for
the operating segments grew approximately 7% on an organic basis over last year.
For the first  nine  months,  revenue  rose $226  million  or 4% over last year.
Excluding the effects of foreign exchange rates,  revenues increased 7% over the
comparable nine-month period.  Improvements in brokerage commissions and fees as
well as premiums earned were partially offset by a decline in investment  income
resulting from lower interest rates and higher losses on disposals.

Brokerage  commissions  and fees  increased $121 million or 10% in third quarter
2001 and $341  million or 10% on a  year-to-date  basis.  This  improvement  was
primarily  from  organic  growth,  business  combination  activity,   especially
Actuarial Sciences Associates,  Inc. (ASA) and ASI Solutions Incorporated (ASI),
increased new business and the impact of increased property and casualty premium
rates,  offset somewhat by unfavorable  results in U.S. retail brokerage related
to the business transformation.

Premiums and other is primarily  related to insurance  underwriting  operations.
Premiums and other  improved $34 million over third quarter 2000,  and increased
$75  million  or 5% in the first  nine  months of 2001,  compared  with the same
period last year. In the third quarter,  growth in the accident and health lines
as well as the impact of acquisitions,  including First Extended, Inc., acquired
in July 2001,  was somewhat  offset by the loss of some accounts in the warranty
business,  in addition to a general  slowdown  of the  market.  The  increase in
premiums  earned for the first nine months  primarily  reflects strong growth in
low margin new business initiatives, continued organic growth, and the impact of
acquisitions.

Investment  income,  which  includes  related  expenses  and  income  or loss on
disposals and impairments, decreased significantly in both the third quarter and
the first nine months of 2001 when compared to prior year,  primarily reflecting
reduced valuations on equity investments in limited  partnerships and reductions
in  short-term  interest  rates  for  both the  quarter  and  year-to-date.  The
nine-month comparison is also negatively impacted by the impairment recorded for
certain  directly owned equity  investments in the first quarter 2001.  Revenues
from private equity investments tend to fluctuate due to the inherent volatility
of equity  investments.  Investment  income from  Insurance  Brokerage and Other
Services  and  Consulting  segments,  primarily  relating  to  fiduciary  funds,
decreased  $2 million  and $5 million in third  quarter  and nine  months  2001,
respectively,  compared  to similar  periods in 2000,  primarily  as a result of
declines in rates.

Total  expenses  increased  $238  million  or 15% over  third  quarter  2000 due
partially to  acquisitions,  the inclusion of charges related to the World Trade
Center tragedy in the quarter and additional unanticipated costs to run parallel
systems.  Total expenses,  excluding the World Trade Center  charges,  rose 12%.
General expenses  increased $176 million or 15% in the quarter reflecting growth
of our  businesses,  higher  costs in the U.S.  retail  brokerage  business  and
increased   business   transformation    implementation   costs.   Benefits   to
policyholders  rose $14 million or 5%. Interest  expense  declined $7 million or
18%, driven by lower short-term interest rates and lower average debt levels.

For nine  months,  total  expenses  increased  $671  million  or 14% over  2000,
partially  driven by the  inclusion  of unusual and special  charges  this year.
Excluding  these  charges,  total  expenses  rose $400  million  or 9%.  General
expenses grew $562 million or 15%,  reflecting  special charges of $218 million,
along with  expenditures  to grow the  brokerage  business  and higher  business
transformation  costs.  Benefits  to  policyholders  rose $57 million or 7% as a
result of new  underwriting  initiatives  and an unusual  increase  in  warranty
claims  during the first  quarter 2001 related to an isolated  program that will

                                     - 16 -


not affect future quarters.  Interest expense declined $4 million or 4% compared
to prior year  attributed  to decreases in short-term  interest  rates and lower
average debt balances.

For the  quarter,  income  before  income tax declined  significantly  from $244
million in 2000 to $133 million in 2001,  due partially to the inclusion in 2001
of  expenses  related  to the  events  of  September  11 ($53  million)  with no
comparable  amount in the third  quarter of 2000.  In addition,  slower  revenue
growth in the U.S. retail brokerage  business due to the  implementation  of the
business  transformation plan and slower  organic  revenue  growth  in  the
consulting  segment  negatively  impacted  results.  Similarly,  nine month 2001
results  declined from 2000 by 64% to $245 million from $690 million due to 2001
business  transformation  special  charges of $218  million,  World Trade Center
charges of $53 million and a decline in consolidated  investment  income of $190
million.

As a result of these  factors,  third  quarter  2001 net income  declined to $72
million ($0.26 per dilutive  share) compared to $139 million ($0.53 per dilutive
share) in 2000.  Basic net income per share was $0.26 and $0.53 in third quarter
2001 and 2000, respectively.  For the first nine months 2001 net income declined
to $120 million ($0.44 per dilutive  share)  compared to $384 million ($1.46 per
dilutive  share) in 2000.  In 2000,  the  company  adopted  the  Securities  and
Exchange  Commission's  Staff  Accounting  Bulletin  101,  which  resulted  in a
one-time  cumulative  non-cash charge of $7 million after-tax ($0.03 per share).
Basic net income per share was $0.44 and $1.47 for the first nine months of 2001
and 2000,  respectively.  Dividends on the redeemable  preferred stock have been
deducted from net income to compute income per share. The effective tax rate was
39% for both third quarter and nine months 2001 and 2000, respectively.


OPERATING SEGMENTS
- ------------------

INSURANCE BROKERAGE AND OTHER SERVICES
- --------------------------------------

The Insurance Brokerage and Other Services segment consists principally of Aon's
retail,  reinsurance  and  wholesale  brokerage  operations  as well as managing
underwriting,  actuarial,  loss control,  claims,  alternative risk transfer and
premium financing services.  This segment represented 58% and 60% of Aon's total
revenues for the third quarter and first nine months of 2001, respectively.

Third  quarter 2001  Insurance  Brokerage  and Other  Services  revenue was $1.1
billion,  up 7% over last year.  Excluding foreign  exchange,  revenues rose 8%.
Year-to-date,  revenues  of $3.4  billion  improved 6% over the  previous  year.
Eliminating the effect of foreign  exchange,  revenues  increased by 9%. Organic
revenue growth was 6% in the quarter, principally reflecting slower new business
growth in U.S.  retail  brokerage  due in part to unexpected  complications  and
delays in the implementation of the business  transformation plan and the events
of September  11. Claims  services and  international  and  wholesale  brokerage
posted solid revenue growth for both the quarter and year-to-date periods.

U.S.  revenue of $597 million for the quarter was up 9% from 2000. For the first
nine months, revenues climbed 8% to $1.7 billion. For both periods, the increase
reflects growth in U.S. specialty operations, improved pricing and acquisitions,
all of which more than  offset the direct and  indirect  impact of the  business
transformation  plan on the U.S.  retail  operation  and the World Trade  Center
tragedy.  U.S. retail new account  generation  during 2001 grew at a slower rate
than anticipated in certain U.S. retail  brokerage units as operational  changes
were implemented to achieve  long-term  benefits of the business  transformation
plan.  Commercial  property and casualty premium rate increases were evident for
most  lines of  coverage  and  client  demand for risk  retention  programs  and
services  has risen  along with the upward  trend in  premium  rates.  U. K. and
Continent  of Europe  revenues of $376  million  for the third  quarter and $1.2
billion for the first nine

                                     - 17 -


months of 2001 increased 3% and 4%,  respectively,  from 2000,  primarily due to
organic growth and  acquisitions.  The reported  revenue growth was  unfavorably
impacted  by the  effect  of  foreign  exchange  rates.  Rest of  world  revenue
increased  $11 million or 9% over third  quarter 2000 and $36 million or 9% over
the first nine months 2000  reflecting  solid organic growth  resulting from new
business and good renewal rates and the positive  impact of hardening  insurance
markets, in addition to new business and the impact of acquisitions.

Pretax income,  including unusual charges related to the World Trade Center, was
$145 million for the third quarter 2001. Excluding these charges,  pretax income
of $153 million declined 16% over 2000.  Pretax margins,  excluding the charges,
were 13.8% in the quarter compared to 17.6% in 2000. Year-to-date, pretax income
was $349 million. Excluding unusual and special charges, nine months 2001 pretax
income was  essentially  flat at $544  million.  Pretax  margins  excluding  the
charges were 16.1% for 2001 versus 17.1% last year. For both periods, the margin
decline was  principally  driven by slower new  business  growth and higher lost
business in the U.S. retail brokerage operations.  In addition,  higher costs in
certain parts of the U.S. retail  business,  due to the business  transformation
process,  including expense to run parallel systems longer than expected,  along
with significant growth in our claims service business,  which has lower margins
also  contributed to the margin  decline.  These items more than offset business
transformation savings.


CONSULTING
- ----------

The  consulting  segment  provides  a full  range  of  services  related  to the
management of human capital, benefits and business processes. These services are
delivered to a predominately corporate clientele utilizing four practice groups:
employee  benefits,  compensation,  management  consulting and outsourcing.  The
acquisition  of ASI further  strengthened  Aon's  outsourcing  and  compensation
consulting services.  This segment accounted for 12% of Aon's total revenues for
both the quarter and first nine months of 2001.

Third quarter 2001 revenue increased 27% to $232 million.  Excluding the foreign
exchange impact,  revenues grew 29%. For the first nine months, revenues of $673
million  represent a 25%  increase  over 2000.  Excluding  the impact of foreign
exchange  rates,  the growth rate was 28%. For the third quarter  2001,  revenue
grew 4% on an  organic  basis  reflecting  a  slowdown  on hiring by some of our
clients and the impact of September 11. On a global basis,  the  improvement  in
revenue for both periods was influenced by acquisition activity,  especially the
inclusion of ASA acquired in fourth quarter 2000,  and to a lesser extent,  ASI,
acquired in the second  quarter 2001, as well as organic  growth.  Client demand
for  solutions  that enhance  workforce  productivity  continued.  However,  the
worsening economy has put some pressure on organic revenue growth.

For the  quarter,  U.S.  revenue of $161  million  was up 36% from  2000,  while
year-to-date revenue of $453 million represents a 39% increase. In both periods,
the  improvement  reflects the impacts of  acquisitions  and for the nine months
strong fundamental operating performance,  particularly in the employee benefits
area.  U.S.  organic growth was flat for the quarter due to the slowing  economy
and the World Trade Center disaster.  U.K. revenue increased by 6% for the third
quarter over the prior year. U.K. revenue for the nine-month  period declined 4%
compared with 2000,  reflecting  the sale of the financial  planning  consulting
business last year, along with unfavorable foreign exchange rates.  Continent of
Europe  revenue  rose $2 million  for the quarter and $4 million for nine months
compared to 2000.

Pretax  income was $29 million for the quarter,  a 12% increase  over last year.
Year-to-date,  pretax income was $77 million.  Excluding special charges, pretax
income of $84 million was 24% better than 2000.  Pretax  margins in this segment
were 12.5% in the quarter  compared to 14.3% in 2000.  For nine  months,  pretax

                                     - 18 -


margins  before  special  charges were 12.5% in 2001  compared to 12.6% in 2000.
Margin deterioration in the quarter is primarily due to lower levels of employee
hiring on the part of Aon/ASI  outsourcing  clients  and the impact of the World
Trade Center disaster.

INSURANCE UNDERWRITING
- ----------------------

The  Insurance  Underwriting  segment  provides  accident  and  health  and life
insurance  coverage through  distribution  networks,  most of which are directly
owned by Aon's  subsidiaries,  and  extended  warranty and property and casualty
insurance  products.  This segment  represented  30% of Aon's total revenues for
both the third quarter and first nine months of 2001.

Revenue was $565 million in the third quarter 2001, an increase of 5% from 2000.
Year-to-date,  revenues of $1.7  billion in 2001  represented  an increase of 4%
over 2000. Excluding the impact of exchange rates, revenues rose 7% for both the
quarter and nine months. For both periods, improvement over last year was driven
by the development of new product initiatives and a higher volume of business in
accident and health  products,  which continued to expand  distribution  through
worksite marketing programs.

U.S.  revenue  increased  $25 million in the third quarter 2001 to $409 million.
For nine  months  2001,  revenues  rose 5% from 2000 to $1.2  billion.  For both
periods,  higher revenues reflect new product initiatives and increased revenues
for accident and health products,  due in part to acquired business,  which more
than  offset a decline in  electronic  warranty  products.  United  Kingdom  and
Continent  of Europe  revenue of $105  million  increased 6% during the quarter,
while year-to-date,  revenues increased 1% to $316 million.  Unfavorable foreign
exchange  rates and the slowdown of business in the warranty area offset organic
growth in the accident and health sector.  Rest of world revenue was $51 million
for the third  quarter,  down $2 million from 2000. For the first nine months of
2001,  revenue was up 3% to $156  million,  due  principally  to growth in Latin
America.

Pretax  income was $35 million for the  quarter.  Excluding  this year's  charge
related to the World Trade  Center,  pretax income was  relatively  flat to last
year at $80 million.  Year-to-date,  pretax income was $158  million.  Excluding
both  unusual  and  special  charges,  pretax  income of $227  million  was flat
compared  to 2000.  Pretax  margins in this  segment  were 14.2% in the  quarter
before  unusual  charges  compared  to 15.1% in 2000.  A decline  in  investment
income, due in part to lower interest rates,  affected margin comparisons in the
quarter. For nine months, pretax margins before unusual and special charges fell
from 14.0% in 2000 to 13.5% in 2001. For both periods in 2001, new  underwriting
initiatives  drove  premium  growth but also  resulted in increased  benefits to
policyholders.  For the year-to-date comparison, an unusual increase in warranty
claims  occurred  during the first  quarter 2001 related to an isolated  program
that will not affect subsequent quarters.

NON-OPERATING SEGMENT
- ---------------------

CORPORATE AND OTHER
- -------------------

Revenue in this  category  consists  primarily of investment  income  (including
income  or loss  on  disposals,  along  with  impairment  losses)  which  is not
otherwise  reflected in the results of the operating  segments.  Invested assets
and related  investment  income not directly  required to support the  insurance
brokerage and consulting  businesses,  together with the assets in excess of net
policyholder  liabilities of the underwriting businesses and related income, are
allocated to the  Corporate  and Other  segment.  Corporate  and Other  expenses
include general  expenses,  administrative  and certain  information  technology
costs, interest expense and goodwill amortization.

                                     - 19 -


Corporate and Other  revenue for the third  quarter 2001 was $3 million,  versus
$25  million in the third  quarter  2000.  For nine months  2001,  revenue was a
negative  $96 million,  versus  positive  revenue of $77 million last year.  The
falloff in revenue in both periods  primarily  reflects  reduced  valuations for
equity investments in limited partnerships.  The year-to-date comparison is also
affected by the write-down of certain  directly owned equity  investments in the
first quarter 2001.  Revenues from private equity  investments  fluctuate due to
the inherent volatility of equity investments.  Limited partnership  investments
often require longer time horizons to generate income.

Corporate  and Other  expenses for the quarter  were $79 million,  up $8 million
from the same period last year. For the first nine months of 2001, expenses were
$243  million,  an increase of $16 million from the  comparable  period in 2000.
Interest  expense  declined  $7 million  for the  quarter and $4 million for the
first nine months  compared to prior year,  reflecting  lower  interest rates as
well as lower debt levels. General expenses, which were at levels similar to the
first two  quarters of 2001,  rose $14  million  and $17  million  over what was
reported for the quarter and nine months of 2000,  respectively,  due in part to
duplicate  occupancy costs  involving  major moves to new office space.  General
expenses in 2000 benefited  from the gain on sale of a non-core  business in the
U.K. Goodwill amortization  increased as a result of new acquisitions made prior
to July 1, 2001.

The revenue and expense  comparisons  discussed above contributed to the overall
Corporate  and Other pretax loss of $76 million in the quarter  versus a loss of
$46 million last year.  The  year-to-date  loss of $339 million is compared to a
$150 million loss in 2000.

                                     - 20 -


                        CASH FLOW AND FINANCIAL POSITION
                         AT THE END OF NINE MONTHS 2001

Cash flows from operating  activities  represent the net income earned by Aon in
the reported  periods adjusted for non-cash charges as well as changes in assets
and liabilities.  Cash flows provided by operating activities for the first nine
months 2001 were $678 million,  a $144 million  increase over the same period in
2000. Other receivables and liabilities  increased $122 million during the year,
driven by higher deferred  compensation  and other accruals of $61 million and a
$29 million impairment write-off of fixed assets lost in the World Trade Center
tragedy.  This was  partially  offset by the timing of income tax  payments  and
refunds.  The  non-cash  effect of lower  valuations  on the  company's  limited
partnership  portfolio,  coupled with  impairments  on  investments  and loss on
disposals, was partially offset by lower net income.

Investing  activities  used cash of $650  million.  The net sale of  investments
provided  cash of $175  million  during the first nine months of 2001.  This was
offset by the net purchase of short-term  investments of $558 million. Cash used
for  acquisition  activity  during the first nine months 2001 was $101  million,
reflecting both brokerage and consulting acquisitions.

Cash of $646  million was used  during the first nine months 2001 for  financing
activities,  which was $609 million  more than was utilized in 2000.  The higher
usage of cash from last year is primarily  due to a reduction of both short- and
long-term  borrowings in 2001 compared to short-term debt increases  during last
year.  In  addition,  $250  million of  long-term  debt was issued in the second
quarter 2000 with no  corresponding  amount issued in 2001. Cash was used to pay
dividends of $177 million on common stock and $2 million on redeemable preferred
stock during the first nine months of 2001.

Aon's operating subsidiaries anticipate that there will be adequate liquidity to
meet their needs in the foreseeable future.  Aon's liquidity needs are primarily
for  servicing  its debt and for the payment of  dividends  on stock  issues and
capital securities.  The businesses of Aon's operating  subsidiaries continue to
provide  substantial  positive  cash  flow.  Brokerage  cash  flow has been used
primarily  for  business  reinvestment,  acquisition  financing  and payments of
special charge and purchase accounting liabilities. Aon anticipates continuation
of the  company's  positive  cash flow and the ability of the parent  company to
access  adequate  short-term  lines of credit.  In November  2001, Aon announced
that, along with Zurich Financial Services,  it will sponsor a new Bermuda-based
insurance  and  reinsurance  company  and will  invest  $200  million in the new
company. Aon has adequate operating cash to fund this commitment.

Due to the contractual nature of its insurance policyholder  liabilities,  which
are primarily intermediate to long-term in nature, Aon has invested primarily in
fixed  maturities.  With a carrying  value of $2.3  billion,  Aon's  total fixed
maturity  portfolio is invested primarily in investment grade holdings (95%) and
has a fair value that is 100% of amortized cost at September 30, 2001.

Total  assets  increased  $594 million to $22.8  billion  since  year-end  2000.
Invested  assets at September  30, 2001  increased  $368  million from  year-end
levels as higher levels of short-term  investments more than offset lower equity
securities  as  well  as  lower  valuations  and  impairment  charges  in  other
investments.  The amortized  cost and fair value of less than  investment  grade
fixed  maturity  investments  at  September  30, 2001 were $131 million and $119
million, respectively. The carrying value of non-income producing investments in
Aon's portfolio at September 30, 2001 was $48 million, or 0.8% of total invested
assets.

Short-term borrowings decreased at the end of third quarter 2001 by $116 million
when  compared to year-end  2000. At the end of third quarter 2001 notes payable
decreased by $138 million when compared to year-end 2000,  primarily  reflecting
the repayment of foreign debt.

                                     - 21 -


Stockholders'  equity  increased  $238  million  during the first nine months of
2001,  reflecting an increase in paid-in additional capital of $944 million,  of
which  $782  million  was a result of  shares  issued to  acquire  two  entities
controlled  by Aon's  Chairman and Chief  Executive  Officer.  This  increase is
offset with a  corresponding  increase in Treasury Stock.  Paid-in-capital  also
rose as a result of shares  issued for the ASI  acquisition  in May 2001 and the
First  Extended,  Inc.  acquisition  in July 2001.  Net income before  preferred
dividends  for the  first  nine  months  of 2001  was  $120  million.  Partially
offsetting  the equity  increase were  dividends  paid to  stockholders  of $179
million.  Unrealized  investment gains and losses and foreign exchange gains and
losses   fluctuations  from  period  to  period  are  largely  based  on  market
conditions.

At September 30, 2001 stockholders'  equity per share was $13.47, up from $13.02
at December 31, 2000 as the higher equity balance more than offset the increased
number of shares outstanding since year-end.


REVIEW BY INDEPENDENT AUDITORS
- ------------------------------

The condensed  consolidated  financial statements at September 30, 2001, and for
the nine months then ended have been reviewed, prior to filing, by Ernst & Young
LLP, Aon's independent auditors, and their report is included herein.

                                     - 22 -

INDEPENDENT ACCOUNTANTS' REVIEW REPORT



Board of Directors and Stockholders
Aon Corporation

We have reviewed the accompanying  condensed consolidated statement of financial
position of Aon Corporation as of September 30, 2001, and the related  condensed
consolidated  statements of income for the  three-month  and nine-month  periods
ended September 30, 2001 and 2000, and the condensed consolidated  statements of
cash flows for the nine-month  periods ended September 30, 2001 and 2000.  These
financial statements are the responsibility of the Company's management.

We  conducted  our  reviews in  accordance  with  standards  established  by the
American  Institute  of  Certified  Public  Accountants.  A  review  of  interim
financial  information consists principally of applying analytical procedures to
financial  data, and making  inquiries of persons  responsible for financial and
accounting matters. It is substantially less in scope than an audit conducted in
accordance  with auditing  standards  generally  accepted in the United  States,
which will be performed  for the full year with the  objective of  expressing an
opinion regarding the financial statements taken as a whole. Accordingly,  we do
not express such an opinion.

Based on our reviews, we are not aware of any material modifications that should
be made to the accompanying condensed consolidated financial statements referred
to above  for them to be in  conformity  with  accounting  principles  generally
accepted in the United States.

We have  previously  audited,  in accordance with auditing  standards  generally
accepted in the United States, the consolidated  statement of financial position
of Aon  Corporation  as of  December  31,  2000,  and the  related  consolidated
statements  of income,  stockholders'  equity,  and cash flows for the year then
ended,  not  presented  herein,  and in our report  dated  February 8, 2001,  we
expressed an unqualified opinion on those consolidated financial statements.  In
our  opinion,   the  information  set  forth  in  the   accompanying   condensed
consolidated  statement of financial position as of December 31, 2000, is fairly
stated, in all material respects,  in relation to the consolidated  statement of
financial position from which it has been derived.



                                                               ERNST & YOUNG LLP

Chicago, Illinois
November 13, 2001

                                     - 23 -


                                     PART II
                                     -------

                                OTHER INFORMATION
                                -----------------



ITEM 2.     CHANGED IN SECURITIES AND USE OF PROCEEDS

      (a)   Pursuant to a Plan and  Agreement of Merger dated May 3, 2001 by and
            among Aon, Merger  Acquisition  Company,  a Delaware  corporation (a
            wholly owned  subsidiary of Aon)  ("Merger  Sub"),  First  Extended,
            Inc.,  a  Delaware  corporation,   and  the  stockholders  of  First
            Extended,  Inc.  ("Sellers"),  Merger Sub  merged  with and into the
            Company  on July  24,  2001  with  the  result  that  the  surviving
            corporation became a wholly owned subsidiary of Aon and the stock of
            First Extended, Inc. outstanding immediately prior to the merger was
            converted  into an aggregate  2,000,000  shares of Aon Common Stock.
            The merger did not involve any underwriters,  underwriting discounts
            or  commissions,  and Aon believes that the  transaction  was exempt
            from the registration  requirements of the Securities Act of 1933 by
            virtue of Section 4(2) thereof regarding  transactions not involving
            a  public   offering  and  Rule  506  of  Regulation  D  promulgated
            thereunder.  Aon  filed a  Registration  Statement  on  Form  S-3 in
            connection  with the  resale of the  2,000,000  shares of Aon Common
            Stock  by the  Sellers  of  First  Extended.  The  Sellers  of First
            Extended, Inc. will receive all of the proceeds from any sale of the
            Aon Common Stock  offered under the  Registration  Statement on Form
            S-3, and Aon will not receive any proceeds  from the sale of the Aon
            Common Stock offered thereunder.

      (b)   Securities  issued pursuant to an acquisition were disclosed in Part
            II,  Item 2 of Aon's  Quarterly  Report on Form 10Q for the  quarter
            ended June 30, 2001, which is incorporated herein by reference.


ITEM 6.     EXHIBITS AND REPORTS ON FORM 8-K

      (a)   Exhibits - The  exhibits  filed  with this  report are listed on the
            --------
            attached Exhibit Index.

      (b)   Reports on Form 8-K -
            -------------------
            (i)   No  Current  Reports  on Form 8-K were  filed for the  quarter
                  ended  September  30,  2001.

            (ii)  The  Registrant  filed  one  Current  Report on Form 8-K dated
                  November 8, 2001.  The  following  exhibit was included in the
                  report: Exhibit 99 - Earnings Press Release issued on November
                  7, 2001.

                                     - 24 -

SIGNATURE

Pursuant  to the  requirements  of the  Securities  Exchange  Act of  1934,  the
Registrant  has duly  caused  this  report  to be  signed  on its  behalf by the
undersigned thereunto duly authorized.


                                Aon Corporation
                                ---------------
                                (Registrant)


November 14, 2001               /s/ Harvey N. Medvin
                                --------------------------
                                HARVEY N. MEDVIN
                                EXECUTIVE VICE PRESIDENT AND
                                CHIEF FINANCIAL OFFICER
                                (Principal Financial and Accounting Officer and
                                 authorized signatory on behalf of Registrant)


                                     - 25 -


Aon CORPORATION
- ---------------

Exhibit Number
In Regulation S-K


Item 601 Exhibit Table
- ----------------------


(12) Statements regarding Computation of Ratios.

            (a)   Statement regarding  Computation of Ratio of Earnings to Fixed
                  Charges.

            (b)   Statement  regarding  Computation  of  Ratio  of  Earnings  to
                  Combined Fixed Charges and Preferred Stock Dividends.


(15) Letter re: Unaudited Interim Financial Information

                                     - 26 -



                                                                                                                    EXHIBIT 12(a)

                                            AON CORPORATION AND CONSOLIDATED SUBSIDIARIES
                                              COMBINED WITH UNCONSOLIDATED SUBSIDIARIES
                                          COMPUTATION OF RATIO OF EARNINGS TO FIXED CHARGES


                                                 NINE MONTHS ENDED
                                                   SEPTEMBER 30,                    YEARS ENDED DECEMBER 31,
                                               --------------------- --------------------------------------------------------
 (millions except ratios)                        2001        2000       2000       1999        1998       1997        1996
                                               ---------  ---------- ----------  ---------  ----------  ---------  ----------

                                                                                                  
 Income from continuing operations
    before provision for income taxes
     and minority interest (1)                    $ 245       $ 690    $   854      $ 635     $   931      $ 542       $ 446

 ADD BACK FIXED CHARGES:

    Interest on indebtedness                         98         102        140        105          87         70          45

    Interest on ESOP                                  -           -          -          1           2          3           4

    Portion of rents representative of
      interest factor                                39          37         54         49          51         44          29

                                               ---------  ---------- ----------  ---------  ----------  ---------  ----------
         INCOME AS ADJUSTED                       $ 382       $ 829    $ 1,048      $ 790     $ 1,071      $ 659       $ 524
                                               =========  ========== ==========  =========  ==========  =========  ==========


 FIXED CHARGES:

    Interest on indebtedness                      $  98       $ 102    $   140      $ 105     $    87      $  70       $  45

    Interest on ESOP                                  -           -          -          1           2          3           4

    Portion of rents representative of
       interest factor                               39          37         54         49          51         44          29

                                               ---------  ---------- ----------  ---------  ----------  ---------  ----------
         TOTAL FIXED CHARGES                      $ 137       $ 139    $   194      $ 155     $   140      $ 117       $  78
                                               =========  ========== ==========  =========  ==========  =========  ==========

 RATIO OF EARNINGS TO FIXED CHARGES                 2.8         6.0        5.4        5.1         7.6        5.6         6.7
                                               =========  ========== ==========  =========  ==========  =========  ==========
<FN>

(1)      Income from continuing operations before provision for income taxes and
         minority  interest  includes  unusual charges of $53 million related to
         the World Trade Center tragedy and special  charges of $218 million for
         the nine months  ended  September  30,  2001.  Income  from  continuing
         operations  before  provision  for income taxes and  minority  interest
         includes special charges of $82 million, $313 million, $172 million and
         $90 million for the years ended December 31, 2000, 1999, 1997 and 1996,
         respectively.
</FN>






                                                                                                                       EXHIBIT 12(b)

                                       AON CORPORATION AND CONSOLIDATED SUBSIDIARIES
                                         COMBINED WITH UNCONSOLIDATED SUBSIDIARIES
                                 COMPUTATION OF RATIO OF EARNINGS TO COMBINED FIXED CHARGES
                                             AND PREFERRED STOCK DIVIDENDS


                                                   NINE MONTHS ENDED
                                                     SEPTEMBER 30,                       YEARS ENDED DECEMBER 31,
                                                ---------------------- ----------------------------------------------------------
 (millions except ratios)                          2001        2000       2000        1999        1998        1997       1996
                                                ----------  ---------- ----------- ----------  ----------  ---------- -----------

                                                                                                      
 Income from continuing operations
    before provision for income taxes
     and minority interest (1)                      $ 245       $ 690     $   854      $ 635     $   931       $ 542       $ 446

 ADD BACK FIXED CHARGES:

    Interest on indebtedness                           98         102         140        105          87          70          45

    Interest on ESOP                                    -           -           -          1           2           3           4

    Portion of rents representative of
      interest factor                                  39          37          54         49          51          44          29

                                                ----------  ---------- ----------- ----------  ----------  ---------- -----------
         INCOME AS ADJUSTED                         $ 382       $ 829     $ 1,048      $ 790     $ 1,071       $ 659       $ 524
                                                ==========  ========== =========== ==========  ==========  ========== ===========


 FIXED CHARGES AND PREFERRED STOCK DIVIDENDS:

    Interest on indebtedness                        $  98       $ 102     $   140      $ 105     $    87       $  70       $  45

    Preferred stock dividends                          52          52          70         70          70          82          29

                                                ----------  ---------- ----------- ----------  ----------  ---------- -----------
         INTEREST AND DIVIDENDS                       150         154         210        175         157         152          74

    Interest on ESOP                                    -           -           -          1           2           3           4

    Portion of rents representative of
       interest factor                                 39          37          54         49          51          44          29

                                                ----------  ---------- ----------- ----------  ----------  ---------- -----------
         TOTAL FIXED CHARGES AND PREFERRED
             STOCK DIVIDENDS                        $ 189       $ 191     $   264      $ 225     $   210       $ 199       $ 107
                                                ==========  ========== =========== ==========  ==========  ========== ===========

 RATIO OF EARNINGS TO COMBINED FIXED
   CHARGES AND PREFERRED STOCK DIVIDENDS (2)          2.0         4.3         4.0        3.5         5.1         3.3         4.9
                                                ==========  ========== =========== ==========  ==========  ========== ===========
<FN>
(1)      Income from continuing operations before provision for income taxes and
         minority  interest  includes  unusual charges of $53 million related to
         the World Trade Center tragedy and special  charges of $218 million for
         the nine months  ended  September  30,  2001.  Income  from  continuing
         operations  before  provision  for income taxes and  minority  interest
         includes special charges of $82 million, $313 million, $172 million and
         $90 million for the years ended December 31, 2000, 1999, 1997 and 1996,
         respectively.

(2)      Included in total fixed charges and preferred  stock  dividends are $49
         million  for the nine months  ended  September  30, 2001 and 2000,  $66
         million for the years ended  December 31, 2000,  1999 and 1998, and $64
         million for the year ended  December 31, 1997, of pretax  distributions
         on the 8.205% mandatorily redeemable preferred capital securities which
         are  classified as "minority  interest" on the  condensed  consolidated
         statements of income.
</FN>



                                                                      Exhibit 15




Board of Directors and Stockholders
Aon Corporation


We are aware of the incorporation by reference in the Registration Statements of
Aon  Corporation  ("Aon")  described in the following  table of our report dated
November  8, 2001  relating  to the  unaudited  condensed  consolidated  interim
financial  statements of Aon Corporation  that are included in its Form 10-Q for
the quarter ended September 30, 2001:

Registration Statement
Form            Number                               Purpose

S-8          33-27984          Pertaining to Aon's savings plan
S-8          33-42575          Pertaining to Aon's stock award plan and stock
                                 option plan
S-8          33-59037          Pertaining to Aon's stock award plan and stock
                                 option plan
S-4          333-21237         Offer to exchange Capital Securities of Aon
                                 Capital A
S-3          333-50607         Pertaining to the registration of 369,000 shares
                                 of common stock
S-8          333-55773         Pertaining to Aon's stock award plan, stock
                                 option plan and employee  stock purchase plan
S-3          333-78723         Pertaining to the registration of debt
                                 securities, preferred stock and common stock
S-3          333-49300         Pertaining to the registration of 3,864,
                                 824 shares of common stock
S-4          333-57706         Pertaining to the registration of up to
                                 3,852,184 shares of common stock
S-3          333-65624         Pertaining to the registration of 2,000,000
                                 shares of common stock

Pursuant to Rule 436(c) of the  Securities Act of 1933, our report is not a part
of the registration  statements  prepared or certified by accountants within the
meaning of Section 7 or 11 of the Securities Act of 1933.


                                                               ERNST & YOUNG LLP



Chicago, Illinois
November 13, 2001