EXHIBIT 12 COLUMBUS SOUTHERN POWER COMPANY Computation of Consolidated Ratios of Earnings to Fixed Charges (in thousands except ratio data) Twelve Months Year Ended December 31, Ended 1992 1993 1994 1995 1996 9/30/97 Fixed Charges: Interest on First Mortgage Bonds. . . . . . . . $ 75,866 $74,119 $68,471 $66,811 $59,711 $55,385 Interest on Other Long-term Debt. . . . . . . . 11,430 10,436 10,221 8,829 12,125 13,920 Interest on Short-term Debt . . . . . . . . . . 3,282 1,305 817 1,328 2,400 4,841 Miscellaneous Interest Charges. . . . . . . . . 3,158 4,036 4,566 4,657 4,374 4,782 Estimated Interest Element in Lease Rentals . . 4,100 3,700 3,700 4,100 4,600 4,600 Total Fixed Charges. . . . . . . . . . . . $97,836 $93,596 $87,775 $85,725 $83,210 $83,528 Earnings: Net Income (Loss) . . . . . . . . . . . . . . . $ 76,244 $(55,898) $109,845 $110,616 $107,108 $117,969 Plus Federal Income Taxes . . . . . . . . . . . 27,389 34,154 49,838 58,648 60,302 67,146 Plus State Income Taxes . . . . . . . . . . . . - - 1 7 11 11 Plus Fixed Charges (as above) . . . . . . . . . 97,836 93,596 87,775 85,725 83,210 83,528 Total Earnings . . . . . . . . . . . . . . $201,469 $ 71,852 $247,459 $254,996 $250,631 $268,654 Ratio of Earnings to Fixed Charges. . . . . . . . 2.05 0.76(a) 2.81 2.97 3.01 3.21 (a) Ratio includes the effect of the Loss from Zimmer Plant Disallowance of $144,533,000 (net of applicable income taxes of $14,534,000). As a result, earnings for the twelve months ended December 31, 1993 were inadequate to cover fixed charges by $21,744,000. If the effect of the Loss from Zimmer Plant Disallowance were excluded, the ratio would be 2.46 for the twelve months ended December 31, 1993.