<PAGE>   1



                                  EXHIBIT 11

                   COMPUTATION OF EARNINGS PER COMMON SHARE


<PAGE>   2



                                                                      EXHIBIT 11
                                                                     PAGE 1 OF 2


                 UNION PLANTERS CORPORATION AND SUBSIDIARIES
               COMPUTATION OF PRIMARY EARNINGS PER COMMON SHARE


<TABLE>
<CAPTION>
                                                      THREE MONTHS ENDED                           SIX MONTHS ENDED
                                                             JUNE 30,                                  JUNE 30,
                                                 -------------------------------          --------------------------------
                                                    1997                 1996                 1997                 1996
                                                 ----------          -----------          -----------           ----------
                                                               (DOLLARS IN THOUSANDS, EXCEPT PER SHARE DATA)
<S>                                             <C>                  <C>                  <C>                  <C>       
PRIMARY EARNINGS PER COMMON SHARE
Average shares outstanding                       66,445,025           63,305,728           65,906,067           63,076,952
Assumed exercise of options outstanding           1,284,968            1,212,197            1,343,215            1,223,343
                                                -----------          -----------          -----------          -----------
Primary average shares outstanding               67,729,993           64,517,925           67,249,282           64,300,295
                                                ===========          ===========          ===========          ===========

Net earnings                                    $    59,853          $    48,624          $   119,045          $    95,776
Less: Preferred stock dividends
        Series B                                          -                   43                    -                  (45)
        Series E                                     (1,213)              (1,748)              (2,709)              (3,496)
                                                -----------          -----------          -----------          -----------

Net earnings applicable to common shares        $    58,640          $    46,919          $   116,336          $    92,235
                                                ===========          ===========          ===========          ===========

Primary earnings per common share                      $.87                 $.72                $1.73                $1.42

</TABLE>



<PAGE>   3


                                                                      EXHIBIT 11
                                                                     PAGE 2 OF 2

                 UNION PLANTERS CORPORATION AND SUBSIDIARIES
            COMPUTATION OF FULLY DILUTED EARNINGS PER COMMON SHARE

<TABLE>
<CAPTION>
                                                       THREE MONTHS ENDED                         SIX MONTHS ENDED
                                                             JUNE 30,                                  JUNE 30,
                                                --------------------------------          --------------------------------
                                                    1997                  1996                1997                 1996
                                                -----------          -----------          -----------          -----------
                                                              (DOLLARS IN THOUSANDS, EXCEPT PER SHARE DATA)
<S>                                             <C>                  <C>                  <C>                  <C>        
FULLY DILUTED EARNINGS PER COMMON SHARE

Average shares outstanding                       66,445,025           63,305,728           65,906,067           63,076,952
Assumed exercise of options outstanding           1,472,711            1,213,108            1,437,953            1,249,906
Assumed conversion of preferred stock
 outstanding:
      Series B                                            -              108,278                    -              224,023
      Series E                                    3,311,195            4,365,076            3,683,533            4,367,800
                                                -----------          -----------          -----------          -----------
Fully diluted average shares outstanding         71,228,931           68,992,190           71,027,553           68,918,681
                                                ===========          ===========          ===========          ===========

Net earnings                                         59,853               48,624              119,045               95,776
Less: Preferred stock dividends                           -                    -                    -                    -
                                                -----------          -----------          -----------          -----------

Net earnings applicable to common shares        $    59,853          $    48,624          $   119,045          $    95,776
                                                ===========          ===========          ===========          ===========

Fully diluted earnings per common share         $       .84          $       .70          $      1.68          $      1.38

</TABLE>