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                                                                   EXHIBIT 23(b)

            CONSENT OF ERNST & YOUNG LLP, INDEPENDENT AUDITORS

          We consent to the reference to our firm under the caption "Experts"
in the Registration Statement (Form S-4) and related Prospectus of Aon
Corporation for the registration of $250,000,000 of 6.20% Notes due 2007 and
to the incorporation by reference therein of our report dated February 12,
2002 (except for Note 1, as to which the date is August 14, 2002), with
respect to the consolidated financial statements and the related financial
statement schedules (as restated) of Aon Corporation included in its Annual
Report (Form 10-K/A) for the year ended December 31, 2001 filed with the
Securities and Exchange Commission.

                                                 /s/ ERNST & YOUNG LLP

Chicago, Illinois
October 8, 2002