EXHIBIT 11 Aon Corporation and Subsidiaries CONSOLIDATED NET INCOME PER SHARE COMPUTATION (millions except per share data) Third Quarter Ended Nine Months Ended -------------------------- -------------------------- Sept. 30, Sept. 30, Sept. 30, Sept. 30, 1996 1995 1996 1995 ------------ ------------ ------------ ------------ EARNINGS PER SHARE Net income ............................................. $ 83.8 $ 100.0 $ 289.0 $ 309.9 Preferred stock dividends .............................. 5.0 5.8 15.2 19.4 ------------ ------------ ------------ ------------ Net income available for common stockholders....... $ 78.8 $ 94.2 $ 273.8 $ 290.5 ============ ============ ============ ============ Average common shares issued ........................... 111.5 110.8 111.5 110.6 Net effect of treasury stock activity .................. (3.1) (3.4) (3.0) (2.8) Net effect of dilutive stock compensation plans based on the treasury stock method ..................... 1.0 0.7 1.2 0.7 ------------ ------------ ------------ ------------ Average common and common equivalent shares outstanding ............................... 109.4 108.1 109.7 108.5 ============ ============ ============ ============ Net income per share ........................................ $ 0.72 $ 0.87 $ 2.50 $ 2.68 ============ ============ ============ ============ - 18 -