1
EXHIBIT 11B
GATX CORPORATION AND SUBSIDIARIES
COMPUTATION OF DILUTED NET INCOME PER SHARE OF COMMON STOCK
(IN MILLIONS, EXCEPT PER SHARE AMOUNTS)
<Table>
<Caption>
THREE MONTHS ENDED SIX MONTHS ENDED
JUNE 30 JUNE 30
------------------------------- ------------------------------
2001 2000 2001 2000
------------- ------------ -------------- ------------
Average number of shares of common stock
outstanding 48.5 47.6 48.4 48.0
Shares issuable upon assumed exercise of stock
options, reduced by the number of shares which
could have been purchased with the proceeds from
exercise of such options .7 .9 .8 .8
Common stock issuable upon assumed
conversion of preferred stock .1 .1 .1 .1
------------- ------------ -------------- ------------
Total 49.3 48.6 49.3 48.9
============= ============ ============== ============
Net income, as adjusted per basic computation $ 21.6 $ 41.5 $ 192.3 $ 82.1
Add - dividends paid and accrued on preferred
stock -- -- -- -
------------- ------------ -------------- ------------
Net income, as adjusted $ 21.6 $ 41.5 $ 192.3 $ 82.1
============= ============ ============== ============
Diluted net income per share:
Income from continuing operations $ .46 $ .67 $ .55 $ 1.43
(Loss) income from discontinued operations (.02) .19 3.35 .25
------------- ------------ -------------- ------------
Total diluted net income per share $ .44 $ .86 $ 3.90 $ 1.68
============= ============ ============== ============
</Table>
18