<PAGE>

                                   EXHIBIT 11

                       OGDEN CORPORATION AND SUBSIDIARIES

     DETAIL OF COMPUTATION OF EARNINGS PER SHARE APPLICABLE TO COMMON STOCK


<TABLE>
<CAPTION>

                                              FOR THE SIX MONTHS ENDED JUNE 30,
                             ----------------------------------------------------------------------
                                           2000                                1999
                             ---------------------------------- -----------------------------------
                                Loss       Shares     Per-Share    Income       Shares    Per-Share
                             (Numerator)(Denominator)  Amount   (Numerator)  (Denominator)  Amount
                             ---------- -------------  ------   -----------  -------------  ------
                                         (In Thousands, Except per Share Amounts)

<S>                          <C>           <C>         <C>       <C>            <C>       <C>
Income (loss) from
continuing operations        $(14,588)                            $20,327
Less: preferred stock
dividends                          34                                  70
                             --------                             -------
Basic Earnings (Loss)
Per Share                     (14,622)      49,515      $(0.30)    20,257        49,043    $ 0.41
                              -------                   ------                             ------


Effect of Dilutive
Securities:

Stock options                                 (A)                                   498

Convertible preferred
stock                                         (A)                      70           250

6% convertible debentures                     (A)                                   (A)

5 3/4% convertible
debentures                                    (A)                                   (A)
                              --------      ------               --------        ------
Diluted Earnings (Loss)
Per Share                     $(14,622)     49,515      $(0.30)   $20,327        49,791    $ 0.41
                              --------      ------      ------   --------        ------    ------

</TABLE>


(A) Anti-dilutive


    Note:
      Basic earnings per common share was computed by dividing net income,
      reduced by preferred stock dividend requirements, by the weighted average
      of the number of shares of common stock outstanding during each period.

      Diluted earnings per common share was computed on the assumption that all
      convertible debentures, convertible preferred stock, and stock options
      converted or exercised during each period, or outstanding at the end of
      each period were converted at the beginning of each period or the date of
      issuance or grant, if dilutive. The computation provides for the
      elimination of related convertible debenture interest and preferred
      dividends.
<PAGE>

                                   EXHIBIT 11

                       OGDEN CORPORATION AND SUBSIDIARIES

                   DETAIL OF COMPUTATION OF EARNINGS PER SHARE





<TABLE>
<CAPTION>

                                               FOR THE THREE MONTHS ENDED JUNE 30,
                                             2000                               1999
                                -----------------------------------  --------------------------------
                                    Loss       Shares     Per-Share   Income      Shares    Per-Share
                                (Numerator) (Denominator)  Amount   (Numerator) (Denominator) Amount
                                ----------- -------------  ------   ----------- ------------- ------
                                                   (In Thousands, Except for Share Amounts)

<S>                               <C>          <C>            <C>       <C>        <C>         <C>
Income (loss) from
continuing operations              $(10,414)                            $16,268
Less: preferred stock
dividends                                17                                  35
                                   --------                             -------
Basic Earnings (Loss)
Per Share                           (10,431)    49,534        $(0.21)    16,233    49,126      $0.33
                                                              ------                           -----

Effect of Dilutive
Securities:
Stock options                                    (A)                                  503

Convertible preferred stock                      (A)                         35       249

6% convertible debentures                        (A)                                  (A)

5 3/4% convertible debentures                    (A)                                  (A)
                                  --------     ------                   -------    ------

Diluted Earnings (Loss)
Per Share                         $(10,431)    49,534         $(0.21)   $16,268    49,878      $0.33
                                  --------     ------         ------    -------    ------      -----
</TABLE>


(A)   Anti-dilutive

    Note:
      Basic earnings per common share was computed by dividing net income,
      reduced by preferred stock dividend requirements, by the weighted average
      of the number of shares of common stock outstanding during each period.

      Diluted earnings per common share was computed on the assumption that all
      convertible debentures, convertible preferred stock, and stock options
      converted or exercised during each period, or outstanding at the end of
      each period were converted at the beginning of each period or the date of
      issuance or grant, if dilutive. The computation provides for the
      elimination of related convertible debenture interest and preferred
      dividends.