================================================================================ UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Form 13F Form 13F COVER PAGE Report for the Calendar Year or Quarter Ended: June 30, 2011 Check here if Amendment [X]; Amendment Number: 2 This Amendment (Check only one.): [_] is a restatement. [X] adds new holdings entries. Institutional Investment Manager Filing this Report: Name: Arthur J. Gallagher & Co. Address: Two Pierce Place Itasca, Illinois 60143 Form 13F File Number: 28-14530 The institutional investment manager filing this report and the person by whom it is signed hereby represent that the person signing the report is authorized to submit it, that all information contained herein is true, correct and complete, and that it is understood that all required items, statements, schedules, lists, and tables, are considered integral parts of this form. Person Signing this Report on Behalf of Reporting Manager: Name: April J. Hanes-Dowd Title: Assistant Secretary Phone: (630) 773-3800 Signature, Place, and Date of Signing: /s/ April J. Hanes-Dowd Itasca, Illinois September 8, 2011 ---------------------------- ----------------------- --------------------- [Signature] [City, State] [Date] Explanatory Note: Due to an inadvertent administrative error, the Form 13F filed by this reporting manager on August 12, 2011 did not contain the General Motors Company holdings listed below. Report Type (Check only one.): [X] 13F HOLDINGS REPORT. (Check here if all holdings of this reporting manager are reported in this report). [_] 13F NOTICE. (Check here if no holdings reported are in this report, and all holdings are reported by other reporting manager(s)). [_] 13F COMBINATION REPORT. (Check here if a portion of the holdings for this reporting manager are reported in this report and a portion are reported by other reporting manager(s)). List of Other Managers Reporting for this Manager: ================================================================================ Form 13F SUMMARY PAGE Report Summary: Number of Other Included Managers: 2 Form 13F Information Table Entry Total: 3 Form 13F Information Table Value Total: $ 230,043 (thousands) Provide a numbered list of the name(s) and Form 13F file number(s) of all institutional investment managers with respect to which this report is filed, other than the manager filing this report. No. Form 13F File Number Name 1 28-14533 Gallagher Fiduciary Advisors, LLC 2 28-14532 Gallagher Benefit Services, Inc. -2- COLUMN 1 COLUMN 2 COLUMN 3 COLUMN 4 COLUMN 5 COLUMN 6 COLUMN 7 COLUMN 8 SHRS NAME OF ISSUER TITLE OF VALUE OR PRN SH/ PUT/ INVESTMENT OTHER VOTING AUTHORITY CLASS CUSIP (x$1000) AMT PRN CALL DISCRETION MANAGERS SOLE SHARED NONE General Motors Company COM 37045V100 39671 1306685 SH DEFINED 1, 2 1055329 251356 General Motors W EXP Company 7/10/2016 37045V118 66104 2177350 SH DEFINED 1, 2 1758571 418779 General Motors W EXP Company 7/10/2019 37045V126 124268 3423350 SH DEFINED 1, 2 2764881 658469