EXHIBIT 5.1
[LETTERHEAD OF SIDLEY & AUSTIN APPEARS HERE]
February 5, 1997
The Board of Directors
Aon Corporation
123 North Wacker Drive
Chicago, Illinois 60606
Re: Aon Corporation
Registration Statement on Form S-4
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Ladies and Gentlemen:
We refer to the Registration Statement on Form S-4 (the "Registration
Statement") being filed by Aon Corporation, a Delaware corporation (the
"Company"), and Aon Capital A, a special purpose statutory business trust
created under the laws of the State of Delaware (the "Trust"), with the
Securities and Exchange Commission under the Securities Act of 1933, as amended
(the "Securities Act"), relating to: (i) the exchange offer by the Trust of
$800,000,000 aggregate Liquidation Amount of the 8.205% Capital Securities
(liquidation amount $1,000 per Capital Security) of the Trust (the "New Capital
Securities") for up to $800,000,000 aggregate Liquidation Amount of the
outstanding 8.205% Capital Securities (liquidation amount $1,000 per Capital
Security) of the Trust (the "Old Capital Securities"); (ii) the exchange by the
Company with the Trust of $824,000,000 aggregate principal amount of the
Company's 8.205% Junior Subordinated Deferrable Interest Debentures due January
1, 2027 (the "New Debentures") for $824,000,000 aggregate principal amount of
the Company's outstanding 8.205% Junior Subordinated Deferrable Interest
Debentures due January 1, 2027 (the "Old Debentures"); and (iii) the guarantee
(the "New Guarantee") by the Company of the payment of Distributions on, and
payments on liquidation or redemption of, the New Capital Securities pursuant to
the Capital Securities Guarantee Agreement (the "New Guarantee Agreement") to be
entered into between the Company and The Bank of New York, as Trustee (the
"Guarantee Trustee"), which is to be exchanged for the guarantee (the "Old
Guarantee") by the Company of the payment of the Distributions on, and payments
on liquidation or redemption of, the Old Capital Securities pursuant to the
Capital Securities Guarantee Agreement dated as of January 13, 1997 between the
Company and The Bank of New York, as Trustee. The New Capital Securities are to
be issued under the Amended and Restated Trust Agreement dated as of January 13,
1997 (the "Trust Agreement") among the Company, as Depositor, The Bank of New
York, as Property
CHICAGO
SIDLEY & AUSTIN
The Board of Directors
Aon Corporation
February 5, 1997
Page 2
Trustee, The Bank of New York (Delaware), as Delaware Trustee, the
Administrative Trustees named therein and the holders, from time to time, of
undivided beneficial interests in the assets of the Trust. The New Debentures
are to be issued under the Junior Subordinated Indenture dated as of January 13,
1997 between the Company and The Bank of New York, as Debenture Trustee, as
supplemented by the First Supplemental Indenture thereto dated as of January 13,
1997 (collectively, the "Indenture"). Capitalized terms not defined herein have
the meanings specified in the Registration Statement.
We are familiar with the proceedings to date with respect to the
proposed issuance of the New Capital Securities, the New Debentures and the New
Guarantee and have examined such records, documents and questions of law, and
have satisfied ourselves as to such matters of fact, as we have considered
relevant and necessary as a basis for the opinions expressed below.
Based on the foregoing, we are of the opinion that:
1. All necessary corporate action has been taken to authorize and
issue the New Debentures and the New Guarantee.
2. The New Debentures will be legally issued and binding obligations
of the Company (except to the extent enforceability may be limited by applicable
bankruptcy, insolvency, reorganization, moratorium, fraudulent transfer or other
similar laws relating to or affecting the enforcement of creditors' rights
generally and by the effect of general principles of equity, regardless of
whether enforceability is considered in a proceeding in equity or at law) when
(i) the Registration Statement, as finally amended, shall have become effective
under the Securities Act and the Indenture shall have been qualified under the
Trust Indenture Act of 1939, as amended (the "Trust Indenture Act"), and (ii)
the New Debentures shall have been duly executed and authenticated as provided
in the Indenture and shall have been duly delivered against surrender and
cancellation of a like principal amount of the Old Debentures in the manner
described in the Registration Statement.
3. The New Guarantee will be a legally issued and binding obligation
of the Company (except to the extent enforceability may be limited by applicable
bankruptcy, insolvency, reorganization, moratorium, fraudulent transfer or other
similar laws relating to or affecting the enforcement of creditors' rights
generally and by the effect of general principles of equity, regardless of
whether enforceability is considered in a proceeding in equity or at law) when
(i) the Registration Statement, as finally amended, shall have become effective
under the Securities Act and the New Guarantee Agreement shall have been
qualified under the Trust Indenture Act and (ii) the New Guarantee Agreement
shall have been duly executed and delivered by the Company and the Guarantee
Trustee.
CHICAGO
SIDLEY & AUSTIN
The Board of Directors
Aon Corporation
February 5, 1997
Page 3
For purposes of rendering the foregoing opinions, we have relied, as
to various questions of fact material to such opinions, upon certificates of
officers of the Company. We have also examined originals, or copies of
originals certified to our satisfaction, of such agreements, documents,
certificates and other statements of government officials and other instruments,
have examined such questions of law and have satisfied ourselves as to such
matters of fact as we have considered relevant and necessary as a basis for such
opinions. We have assumed the authenticity of all documents submitted to us as
originals, the genuineness of all signatures, the legal capacity of all natural
persons and the conformity with the original documents of any copies thereof
submitted to us for our examination.
The opinions expressed above are limited to the General Corporate Law
of the State of Delaware, the laws of the State of New York and the federal laws
of the United States of America.
We do not find it necessary for the purposes of this opinion to cover,
and accordingly we express no opinion as to, the application of the securities
or blue sky laws of the various states to the issuance of the New Debentures in
exchange for the Old Debentures or to the issuance of the New Guarantee in
exchange for the Old Guarantee.
We hereby consent to the filing of this opinion as an exhibit to the
Registration Statement and to all references to our firm included in or made a
part of the Registration Statement.
Very truly yours,
/s/ Sidley & Austin