EXHIBIT 11 Aon Corporation and Subsidiaries CONSOLIDATED NET INCOME PER SHARE COMPUTATION (millions except per share data) Second Quarter Ended Six Months Ended --------------------------- --------------------------- June 30, June 30, June 30, June 30, 1997 1996 1997 1996 ------------ ------------ ------------ ------------ EARNINGS PER SHARE (1) Net income ................................................. $ 84.2 $ 86.3 $ 84.9 $ 205.2 Preferred stock dividends .................................. 3.3 5.1 6.7 10.2 ------------ ------------ ------------ ------------ Net income available for common stockholders .......... $ 80.9 $ 81.2 $ 78.2 $ 195.0 ============ ============ ============ ============ Average common shares issued ............................... 171.2 167.3 171.2 167.3 Net effect of treasury stock activity and dilutive stock compensation plans based on the treasury stock method . (1.9) (2.6) (2.0) (2.6) ------------ ------------ ------------ ------------ Average common and common equivalent shares outstanding ...................................... 169.3 164.7 169.2 164.7 ============ ============ ============ ============ Net income per share ............................................ $ 0.48 $ 0.49 $ 0.46 $ 1.18 ============ ============ ============ ============ <FN> (1) Adjusted to reflect the three-for-two stock split on May 14, 1997 </FN>