<TABLE>
Exhibit 12a

                      STATEMENT SETTING FORTH COMPUTATIONS OF RATIOS OF
                                 EARNINGS TO FIXED CHARGES
                                   (Dollars in Thousands)
<CAPTION>
                                12 Months
                                   Ending                Year Ended December 31
                                    March  ------------------------------------------------
                                 31, 1998      1997      1996      1995     1994      1993
                                ---------  ------------------------------------------------
<S>                             <C>        <C>       <C>       <C>       <C>      <C>
EARNINGS AVAILABLE FOR
 FIXED CHARGES
  Pre-tax income:
    Income from continuing
      operations per statement
      of income                  $159,093  $125,698  $167,351  $128,382  $79,312  $163,812
    Federal income taxes          103,664    47,725   107,747    91,519   74,816    93,702
    Federal income taxes charged
      to other income - net         9,754    11,876    (1,608)  (12,068)  22,687      (418)
    Capitalized interest             (334)     (360)     (600)     (660)    (400)     (791)
    Undistributed (earnings) or
      losses of less-than-
      fifty-percent-owned
      entities                        165      (608)      460     8,325      743        --
                                 --------  ------------------------------------------------
      Total                      $272,342  $184,331  $273,350  $215,498 $177,158  $256,305

  Fixed charges:
    Interest expense             $129,076  $123,439  $122,635  $131,346 $126,555  $120,962
    Other interest                    334       360       600       660      400       791
    Portion of rentals
      representative of the
      interest factor               3,137     3,143     4,187     5,150    5,555     5,570
                                 --------  ------------------------------------------------
      Total                      $132,547  $126,942  $127,422  $137,156 $132,510  $127,323

  Earnings available for
    combined fixed charges       $404,889  $311,273  $400,772  $352,654 $309,668  $383,628
                                 ========  ================================================
RATIO OF EARNINGS TO
  FIXED CHARGES                     3.05x     2.45x     3.15x     2.57x    2.34x     3.01x
</TABLE>
<PAGE>
<TABLE>
Exhibit 12b

                     STATEMENT SETTING FORTH COMPUTATIONS OF RATIOS OF
             EARNINGS TO COMBINED FIXED CHARGES AND PREFERRED STOCK DIVIDENDS
                                   (Dollars in Thousands)
<CAPTION>
                                12 Months
                                   Ending                Year Ended December 31
                                    March  ------------------------------------------------
                                 31, 1998      1997      1996      1995     1994      1993
                                ---------  ------------------------------------------------
<S>                             <C>        <C>       <C>       <C>       <C>      <C>                                        
EARNINGS AVAILABLE FOR COMBINED
 FIXED CHARGES AND PREFERRED
 DIVIDEND REQUIREMENTS

  Pretax income:
    Income from continuing
      operations per statement
      of income                  $159,093  $125,698  $167,351  $128,382  $79,312  $163,812
    Federal income taxes          103,664    47,725   107,747    91,519   74,816    93,702
    Federal income taxes charged
      to other income - net         9,754    11,876    (1,608)  (12,068)  22,687      (418)
                                 --------  ------------------------------------------------
      Subtotal                    272,511   185,299   273,490   207,833  176,815   257,096
  Capitalized interest               (334)     (360)     (600)     (660)    (400)     (791)
  Undistributed (earnings) or
    losses of less-than-fifty-
    percent-owned entities            165      (608)      460     8,325      743        --
                                 --------  ------------------------------------------------
      Total                      $272,342  $184,331  $273,350  $215,498 $177,158  $256,305

  Fixed charges:
    Interest expense             $129,076  $123,439  $122,635  $131,346 $126,555  $120,962
    Other interest                    334       360       600       660      400       791
    Portion of rentals
      representative of the
      interest factor               3,137     3,143     4,187     5,150    5,555     5,570
                                 --------  ------------------------------------------------
      Total                      $132,547  $126,942  $127,422  $137,156 $132,510  $127,323

Earnings available for
  combined fixed charges
  and preferred dividend
  requirements                   $404,889  $311,273  $400,772  $352,654 $309,668  $383,628
                                 ========  ================================================

DIVIDEND REQUIREMENT:
  Fixed charges above            $132,547  $126,942  $127,422  $137,156 $132,510  $127,323
  Preferred dividend
    requirements below             26,661    26,250    36,249    36,674   45,441    29,904
                                 --------  ------------------------------------------------
      Total                      $159,208  $153,192  $163,671  $173,830 $177,951  $157,227
                                 ========  ================================================
</TABLE>
<PAGE>
<TABLE>
<CAPTION>

                                12 Months
                                   Ending                Year Ended December 31
                                    March  ------------------------------------------------
                                 31, 1998      1997      1996      1995     1994      1993
                                ---------  ------------------------------------------------
<S>                             <C>        <C>        <C>      <C>       <C>       <C>  
RATIO OF EARNINGS TO COMBINED
  FIXED CHARGES AND PREFERRED
  DIVIDEND REQUIREMENTS              2.54      2.03      2.45      2.03     1.74      2.44

COMPUTATION OF PREFERRED
  DIVIDEND REQUIREMENTS:
  (a) Pre-tax income             $272,511  $185,299  $273,490  $207,833  $176,815  $257,096
  (b) Income from continuing
        operations               $159,093  $125,698  $167,351  $128,382  $ 79,312  $163,812
  (c) Ratio of (a) to (b)          1.7129    1.4742    1.6342    1.6189    2.2294    1.5695
  (d) Preferred dividends        $ 15,565  $ 17,806  $ 22,181  $ 22,654  $ 20,383  $ 19,054
  Preferred dividend
    requirements
      [(d) multiplied by (c)]    $ 26,661  $ 26,250  $ 36,249  $ 36,674  $ 45,441  $ 29,904
                                 ========  ================================================
</TABLE>