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                                                                     EXHIBIT 11A


                        GATX CORPORATION AND SUBSIDIARIES

            COMPUTATION OF BASIC 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
                                                                -------------------------------    ------------------------------
                                                                    1999              1998             1999             1998
                                                                -------------      ------------    --------------    ------------

<S>                                                             <C>                <C>             <C>               <C>
Average number of shares of common stock
    outstanding                                                      49.5              49.2            49.4              49.1

Net income                                                        $  38.1           $  30.8         $  77.3           $  68.2

Deduct - Dividends paid and accrued on preferred
   stock                                                               --                --              --                --
                                                                -------------      ------------    --------------    ------------

Net income, as adjusted                                           $  38.1           $  30.8         $  77.3           $  68.2
                                                                =============      ============    ==============    ============

Basic net income per share                                        $   .77           $   .63         $  1.56           $  1.39
                                                                =============      ============    ==============    ============
</TABLE>



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