Pennsylvania Manufacturers Corporation Exhibit 11 Computation of Earnings Per Share (Unaudited) Years ended December 31, (in thousands, except per share data) 1997 1996 1995 --------------------------------------------- Basic: Weighted average shares outstanding 23,855,031 23,800,791 23,816,088 Net income (loss) before extraordinary item $ 19,753 $ (135,334) $ 24,130 Extraordinary loss (4,734) -- -- --------------------------------------------- Net income (loss) $ 15,019 $ (135,334) $ 24,130 ============================================= Net income (loss) per common and equivalent share before extraordinary item $ 0.83 $ (5.68) $ 1.01 Extraordinary item (0.20) -- -- --------------------------------------------- Net income (loss) per common and equivalent share $ 0.63 $ (5.68) $ 1.01 ============================================= Diluted: Weighted average shares outstanding 23,855,031 23,800,791 23,816,088 Net effect of dilutive stock options - based on the treasury stock method using average market price 712,347 -- 965,861 --------------------------------------------- Total diluted common shares 24,567,378 23,800,791 24,781,949 ============================================= Net income (loss) before extraordinary item $ 19,753 $ (135,334) $ 24,130 Extraordinary loss (4,734) -- -- --------------------------------------------- Net income (loss) $ 15,019 $ (135,334) $ 24,130 ============================================= Net income (loss) per common and equivalent share before extraordinary item $ 0.80 $ (5.68) $ 0.97 Extraordinary item (0.19) -- -- --------------------------------------------- Net income (loss) per common and equivalent share $ 0.61 $ (5.68) $ 0.97 =============================================