LETTER 1 filename1.txt December 13, 2005 Mail Stop 4561 By U.S. Mail William A. Osborn Chief Executive Officer Northern Trust Corporation Fifty South LaSalle Street Chicago, IL 60675 Re: Northern Trust Corporation Form 10-K for Fiscal Year Ended December 31, 2004 Filed March 14, 2005 File No. 0-05965 Dear Mr. Osborn: We have completed our review of your Form 10-K and have no further comments at this time. Sincerely, Angela Connell Senior Accountant