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                                    FORM T-1

                       SECURITIES AND EXCHANGE COMMISSION
                             Washington, D.C. 20549

                            STATEMENT OF ELIGIBILITY
                   UNDER THE TRUST INDENTURE ACT OF 1939 OF A
                    CORPORATION DESIGNATED TO ACT AS TRUSTEE

                      CHECK IF AN APPLICATION TO DETERMINE
                      ELIGIBILITY OF A TRUSTEE PURSUANT TO
                              SECTION 305(b)(2) / /

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

                              THE BANK OF NEW YORK

               (Exact name of trustee as specified in its charter)

New York                                                     13-5160382
(State of incorporation                                      (I.R.S. employer
if not a U.S. national bank)                                 identification no.)

One Wall Street, New York, N.Y.                              10286
(Address of principal executive offices)                     (Zip code)

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

                                 Aon CORPORATION
               (Exact name of obligor as specified in its charter)

Delaware                                                     36-3051915
(State or other jurisdiction of                              (I.R.S. employer
incorporation or organization)                               identification no.)

200 East Randolph Street
Chicago, Illinois                                            60601
(Address of principal executive offices)                     (Zip code)

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

                              6.20% Notes due 2007
                       (Title of the indenture securities)

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1.  GENERAL INFORMATION. FURNISH THE FOLLOWING INFORMATION AS TO THE TRUSTEE:

    (a)   NAME AND ADDRESS OF EACH EXAMINING OR SUPERVISING AUTHORITY TO WHICH
          IT IS SUBJECT.

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                Name                                        Address
- ----------------------------------------------------------------------------------
                                              
    Superintendent of Banks of the State of      2 Rector Street, New York, N.Y.
    New York                                     10006, and Albany, N.Y. 12203

    Federal Reserve Bank of New York             33 Liberty Plaza, New York, N.Y.
                                                 10045

    Federal Deposit Insurance Corporation        Washington, D.C.  20429

    New York Clearing House Association          New York, New York   10005
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    (b)   WHETHER IT IS AUTHORIZED TO EXERCISE CORPORATE TRUST POWERS.

    Yes.

2.  AFFILIATIONS WITH OBLIGOR.

    IF THE OBLIGOR IS AN AFFILIATE OF THE TRUSTEE, DESCRIBE EACH SUCH
    AFFILIATION.

    None.

16. LIST OF EXHIBITS.

    EXHIBITS IDENTIFIED IN PARENTHESES BELOW, ON FILE WITH THE COMMISSION,
    ARE INCORPORATED HEREIN BY REFERENCE AS AN EXHIBIT HERETO, PURSUANT TO
    RULE 7a-29 UNDER THE TRUST INDENTURE ACT OF 1939 (THE "ACT") AND 17
    C.F.R. 229.10(d).

    1.    A copy of the Organization Certificate of The Bank of New York
          (formerly Irving Trust Company) as now in effect, which contains the
          authority to commence business and a grant of powers to exercise
          corporate trust powers. (Exhibit 1 to Amendment No. 1 to Form T-1
          filed with Registration Statement No. 33-6215, Exhibits 1a and 1b to
          Form T-1 filed with Registration Statement No. 33-21672 and Exhibit 1
          to Form T-1 filed with Registration Statement No. 33-29637.)

    4.    A copy of the existing By-laws of the Trustee. (Exhibit 4 to Form T-1
          filed with Registration Statement No. 33-31019.)

                                       -2-
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    6.    The consent of the Trustee required by Section 321(b) of the Act.
          (Exhibit 6 to Form T-1 filed with Registration Statement No.
          33-44051.)

    7.    A copy of the latest report of condition of the Trustee published
          pursuant to law or to the requirements of its supervising or examining
          authority.

                                       -3-
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                                    SIGNATURE

    Pursuant to the requirements of the Act, the Trustee, The Bank of New
York, a corporation organized and existing under the laws of the State of New
York, has duly caused this statement of eligibility to be signed on its behalf
by the undersigned, thereunto duly authorized, all in The City of New York, and
State of New York, on the 4th day of October, 2002.

                                         THE BANK OF NEW YORK


                                         By: /s/ MARY BETH LEWICKI
                                             -----------------------------------
                                             Name:  MARY BETH LEWICKI
                                             Title: VICE PRESIDENT

                                       -4-
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                                                                       EXHIBIT 7

                       Consolidated Report of Condition of

                              THE BANK OF NEW YORK

                    of One Wall Street, New York, N.Y. 10286
                     And Foreign and Domestic Subsidiaries,
a member of the Federal Reserve System, at the close of business June 30, 2002,
published in accordance with a call made by the Federal Reserve Bank of this
District pursuant to the provisions of the Federal Reserve Act.

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                                                                               Dollar Amounts
                                                                                In Thousands
                                                                             
ASSETS
Cash and balances due from depository institutions:
   Noninterest-bearing balances and currency and coin..                         $   2,850,111
   Interest-bearing balances...........................                             6,917,898
Securities:
   Held-to-maturity securities.........................                             1,201,319
   Available-for-sale securities.......................                            13,227,788
Federal funds sold in domestic offices.................                             1,748,562
Securities purchased under agreements to resell........                               808,241
Loans and lease financing receivables:
   Loans and leases held for sale......................                               974,505
   Loans and leases, net of unearned
     income............................................              36,544,957
   LESS: Allowance for loan and
     lease losses......................................                 578,710
   Loans and leases, net of unearned
     income and allowance..............................                            35,966,247
Trading Assets.........................................                             6,292,280
Premises and fixed assets (including
   capitalized leases).................................                               860,071
Other real estate owned................................                                   660
Investments in unconsolidated subsidiaries and
   associated companies................................                               272,214
Customers' liability to this bank on acceptances
   outstanding.........................................                               467,259
Intangible assets......................................
   Goodwill............................................                             1,804,922
   Other intangible assets.............................                                70,679
Other assets...........................................                             4,639,158
                                                                                -------------
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Total assets...........................................                         $  78,101,914
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LIABILITIES
Deposits:
   In domestic offices.................................                         $  29,456,619
   Noninterest-bearing.................................              11,393,028
   Interest-bearing....................................              18,063,591
   In foreign offices, Edge and Agreement
     subsidiaries, and IBFs............................                            26,667,608
   Noninterest-bearing.................................                 297,347
   Interest-bearing....................................              26,370,261
Federal funds purchased in domestic offices............                             1,422,522
Securities sold under agreements to repurchase.........                               466,965
Trading liabilities....................................                             2,946,403
Other borrowed money:
   (includes mortgage indebtedness and obligations
   under capitalized leases)...........................                             1,844,526
Bank's liability on acceptances executed and
   outstanding.........................................                               469,319
Subordinated notes and debentures......................                             1,840,000
Other liabilities......................................                             5,998,479
                                                                                -------------
Total liabilities......................................                         $  71,112,441
                                                                                =============

Minority interest in consolidated
   subsidiaries........................................                               500,154

EQUITY CAPITAL
Perpetual preferred stock and related
   surplus.............................................                                     0
Common stock...........................................                             1,135,284
Surplus................................................                             1,055,509
Retained earnings......................................                             4,244,963
Accumulated other comprehensive income.................                               (53,563)
Other equity capital components........................                                     0
Total equity capital...................................                             6,489,319
                                                                                -------------
Total liabilities minority interest and
   equity capital......................................                         $  78,101,914
                                                                                =============
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     I, Thomas J. Mastro, Senior Vice President and Comptroller of the
above-named bank do hereby declare that this Report of Condition is true and
correct to the best of my knowledge and belief.

                                                           Thomas J. Mastro,
                                       Senior Vice President and Comptroller

     We, the undersigned directors, attest to the correctness of this
statement of resources and liabilities. We declare that it has been  examined
by us, and to the best of our knowledge and belief has been prepared in
conformance with the instructions and is true and correct.

Thomas A. Renyi
Gerald L. Hassell
Alan R. Griffith                       Directors