Revised Prospectus Supplement #11

EXPLANATORY NOTE

This prospectus supplement is being filed to correct a typographical error in the name of one of the Selling Stockholders in Prospectus Supplement #11 (to the prospectus dated May 5, 2010) filed on May 25, 2011. No other changes have been made to the prospectus supplement.

Filed Pursuant to Rules 424(b)(7) and 424(c)

Registration Number: 333-166533

PROSPECTUS SUPPLEMENT #11

(to prospectus dated May 5, 2010)

LOGO

SHARES OF COMMON STOCK

The information in this document supplements the information set forth in the prospectus dated May 5, 2010 relating to the registration of our common stock under our Registration Statement on Form S-3 (SEC Registration No. 333-166533). We incorporate this prospectus supplement by reference into the prospectus.

This prospectus supplement relates to 81,492 shares of our common stock issued by us, in a transaction not requiring registration under the Securities Act of 1933, as amended, as partial consideration to acquire all of the insurance brokerage business of the persons named under the heading “Selling Stockholders.” This prospectus supplement and the related prospectus may be used to resell shares of our common stock only by the persons named under the heading “Selling Stockholders.” You should read this supplement together with the prospectus.

We are not offering or selling any securities pursuant to this prospectus supplement. We will not receive any of the proceeds from the sale of these shares by the selling stockholders.

Our common stock is traded on the New York Stock Exchange under the symbol “AJG”. Investing in our common stock involves a high degree of risk. See the discussion under “Risk Factors” beginning on page 2 of the prospectus dated May 5, 2010 and those risk factors contained in the documents we incorporate by reference into such prospectus, to learn about factors you should consider before buying shares of our common stock.

NEITHER THE SECURITIES AND EXCHANGE COMMISSION NOR ANY STATE

SECURITIES COMMISSION HAS APPROVED OR DISAPPROVED OF THESE SECURITIES

OR DETERMINED IF THIS PROSPECTUS IS TRUTHFUL OR COMPLETE. ANY

REPRESENTATION TO THE CONTRARY IS A CRIMINAL OFFENSE.

This prospectus supplement is dated May 25, 2011.


SELLING STOCKHOLDERS

The table below sets forth, for the selling stockholders named herein, to the extent known by us, the number of shares of our common stock beneficially owned, the number of shares of common stock offered hereby and the number of shares and percentage of outstanding common stock to be owned after the completion of this offering.

None of the selling stockholders named herein has held any position or office or had any other material relationship with us or any of our predecessors or affiliates within the past three years other than in connection with our arms-length purchase of their business and as a result of their ownership of our securities.

All information contained in the table below is based upon information provided to us by the selling stockholders, and we have not independently verified this information. Selling stockholders may at any time trade all or some of their shares of our common stock without providing notice to us. Therefore, the table set forth below and comparable tables set forth in previous supplements may not reflect the number of shares of our common stock held by the selling stockholders listed below as of the date of this supplement.

The percentage of shares beneficially owned is based on 110,464,839 shares of our common stock issued and outstanding as of April 30, 2011.

 

Name of Selling

Stockholder

   Number of Shares
Beneficially Owned
Prior to the
Completion
of the Offering
   Number of
Shares
Registered for
Sale Hereby
   Shares Owned After
the Completion of the
Offering
         Number    Percent

John Fish, Jr.

   43,552    43,552    0    *

Eric J. Olson

   29,034    29,034    0    *

Fish & Schulkamp, Inc.

   8,906    8,906    0    *

 

 

* Less than 1%

VALIDITY OF THE SECURITIES

The validity of the shares of common stock offered hereby has been passed upon for us by Seth Diehl, Esq., Senior Counsel, Corporate & Securities of our Company.

Estimated Expenses of Issuance and Distribution

 

Securities and Exchange Commission filing fee      $267   
Accounting fees and expenses        
Legal fees and expenses        
Printing fees      $400   
Miscellaneous        
        

Total expenses

   $ 667   

All of the above fees and expenses will be paid by us. Other than the SEC filing fee, all fees and expenses are estimated.