EXHIBIT NUMBER (11) TO 3/31/96 FORM 10-Q NORTHERN TRUST CORPORATION COMPUTATION OF PER SHARE EARNINGS First Quarter Ended March 31 ------------------------------------------ 1996 1995 ------------ ------------- Computations Required by - ------------------------ Regulation S-K - -------------- Primary Earnings Per Share - -------------------------- Net Income Applicable to Common Shares $60,245,569 $47,181,699 ============ ============ Weighted Average Number of Common and Common Equivalent Shares Outstanding Common Shares 56,258,183 54,250,684 Dilutive Effect of Common Equivalent Shares (A) Stock Options 924,273 586,299 Long Term Performance Stock Plan 263,698 323,123 Other 44,783 8,213 ------------ ------------ 57,490,937 55,168,319 ============ ============ Net Income Per Common and Common Equivalent Share $1.05 $0.86 ============ ============ (A) Determined by application of the treasury stock method. EXHIBIT NUMBER (11) TO 3/31/96 FORM 10-Q NORTHERN TRUST CORPORATION COMPUTATION OF PER SHARE EARNINGS First Quarter Ended March 31 ------------------------------------------ 1996 1995 ------------ ------------ Computations Required by - ------------------------ Regulation S-K - -------------- Fully Diluted Earnings Per Share - -------------------------------- Net Income Applicable to Common Shares $60,245,569 $47,181,699 Add Back: Dividend on Series E Convertible Preferred Stock 14,756 777,147 ------------ ------------ $60,260,325 $47,958,846 ============ ============ Weighted Average Number of Common and Common Equivalent Shares Outstanding Common Shares 56,258,183 54,250,684 Dilutive Effect of Common Equivalent Shares (A) Stock Options 962,193 604,437 Long Term Performance Stock Plan 270,220 326,028 Other 47,860 8,846 Other Potentially Dilutive Securities Equivalent Shares Assuming Conversion of Series E Convertible Preferred Stock 383,954 1,204,820 ------------ ------------ 57,922,410 56,394,815 ============ ============ Net Income Per Common and Common Equivalent Share $1.04 $0.85 ============ ============ (A) Determined by application of the treasury stock method.