UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Form 13F Form 13F COVER PAGE Report for the Calendar Year or Quarter Ended: September 30, 2011 Check here if Amendment; Amendment Number: [ ] This Amendment (Check only one.): [ ] is a restatement. [ ] 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 November 8, 2011 ----------------------- ------------------ ---------------- [Signature] [City, State] [Date] 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: None. Form 13F SUMMARY PAGE Report Summary: Number of Other Included Managers: 2 ----------------- Form 13F Information Table Entry Total: 9 ----------------- Form 13F Information Table Value Total: $ 422,498 ---------------- (thousands) List of Other Included Managers: 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- September 30, 2011 FORM 13F INFORMATION TABLE Voting Authority ---------------- Title of Value Shares/ Sh/ Put/ Investment Other Name of Issuer Class CUSIP (x$1000) Prn Amt Prn Call Discretion Managers Sole Shared None -------------- ----- ----- -------- ------- --- ---- ----------- -------- ---- ------ ---- General Motors Company COM 37045V100 15448 765523 SH DEFINED 1, 2 618207 147316 General Motors Company W EXP 37045V118 20203 1735648 SH DEFINED 1, 2 1401898 333750 7/10/2016 General Motors Company W EXP 37045V126 27888 3516748 SH DEFINED 1, 2 2840388 676360 7/10/2019 Franklin Resources Inc. COM 354613101 84134 879698 SH DEFINED 1, 2 879698 Kaiser Aluminum Corporation COM 483007704 82898 2202495 SH DEFINED 1, 2 2202495 Kaman Corp. COM 483548103 19537 701509 SH DEFINED 701509 PPG Industries Inc. COM 693506107 127492 1804305 SH DEFINED 1, 2 1804305 Solutia Inc. COM 834376501 13582 1056992 SH DEFINED 1, 2 1056992 Windstream Corp. COM 97381W104 31316 2688100 SH DEFINED 1, 2 2688100 REPORT SUMMARY 9 DATA RECORDS $422,498 ALL OTHER MANAGERS ON WHOSE BEHALF REPORT IS FILED - 2