EXHIBIT 12 NIAGARA MOHAWK POWER CORPORATION AND SUBSIDIARY COMPANIES Statement Showing Computation of Ratio of Earnings to Fixed Charges, Ratio of Earnings to Fixed Charges without AFC and Ratio of Earnings to Fixed Charges and Preferred Stock Dividends for the Twelve Months Ended June 30, 1998 (in thousands of dollars) A. Net Income . . . . . . . . . . . . . . . . . . . . $ (81,481) B. Taxes Based on Income or Profits . . . . . . . . . (23,101) ----------------- C. Earnings, Before Income Taxes. . . . . . . . . . . (104,582) D. Fixed Charges (a) . . . . . . . . . . . . . . . . 302,881 ----------------- E. Earnings Before Income Taxes and Fixed Charges . . 198,299 F. Allowance for Funds Used During Construction (AFC) 16,556 ----------------- G. Earnings Before Income Taxes and Fixed Charges without AFC. . . . . . . . . . . . . . . . . . $ 181,743 ================= Preferred Dividend Factor: H. Preferred Dividend Requirements. . . . . . . . . . $ 36,983 I. Ratio of Pre-tax Income to Net Income (C / A). . . (NOT APPLICABLE) ----------------- J. Preferred Dividend Factor (H x I). . . . . . . . . $ 36,983 K. Fixed Charges as Above (D) . . . . . . . . . . . . 302,881 ----------------- L. Fixed Charges and Preferred Dividends Combined . . $ 339,864 ================= M. Ratio of Earnings to Fixed Charges (E / D) . . . . 0.65 ================= N. Ratio of Earnings to Fixed Charges without AFC (G / D) . . . . . . . . . . . . . . 0.60 ================= O. Ratio of Earnings to Fixed Charges and Preferred Dividends Combined (E / L). . . . . . 0.58 ================= (a) Includes a portion of rentals deemed representative of the interest factor ($25,755).