EXHIBIT 11 COMPUTATION OF PRIMARY AND FULLY DILUTED NET INCOME PER COMMON SHARE Three Months Ended March 31 --------------------------- (Dollars in Millions, Except Per Share Data) 1997 1996 - -------------------------------------------------------------------------------- PRIMARY: Average shares outstanding ....................... 133,387,042 134,586,125 Net effect of the assumed purchase of stock under the stock option and stock purchase plans--based on the treasury stock method using average market price ...................... 2,138,297 2,434,786 ------------------------ 135,525,339 137,020,911 ======================== Net income ....................................... $171.8 $176.8 Preferred dividends .............................. -- (1.7) ------------------------ Net income applicable to common equity ........... $171.8 $175.1 ======================== Net income per common share ...................... $ 1.27 $ 1.28 ======================== FULLY DILUTED:* Average shares outstanding ....................... 133,387,042 134,586,125 Net effect of the assumed purchase of stock under the stock option and stock purchase plans--based on the treasury stock method using average market price or period-end market price, whichever is higher ............... 2,150,128 2,693,688 Assumed conversion of Series 1991A Preferred Stock -- 3,443,702 ------------------------ 135,537,170 140,723,515 ======================== Net income........................................ $171.8 $176.8 Preferred dividends, excluding 1991A Preferred Stock ................................. -- -- ------------------------ Net income applicable to common equity ........... $171.8 $176.8 ======================== Net income per common share ...................... $ 1.27 $ 1.26 ================================================================================ * This calculation is submitted in accordance with Regulation S-K item 601(b)(11) although not required by footnote 2 to paragraph 17 of APB Opinion No. 15 because it results in dilution of less than 3%.