EXHIBIT 11.0 KIRBY CORPORATION AND CONSOLIDATED SUBSIDIARIES COMPUTATION OF EARNINGS PER COMMON SHARE Three months ended Nine months ended September 30, September 30, ------------------ ----------------- 1998 1997 1998 1997 ------- ------- ------- ------- (in thousands, except per share amounts) Net earnings (loss) from continuing operations $(6,571) $ 5,873 $ 5,144 $16,186 Net earnings from discontinued operations -- 76 -- 2,607 ------ ------ ------ ------ Net earnings (loss) $(6,571) $ 5,949 $ 5,144 $18,793 ====== ====== ====== ====== Basic earnings per share: Weighted average number of common shares outstanding 21,175 24,313 22,181 24,405 ====== ====== ====== ====== Basic earnings (loss) per share from continuing operations $ (.31) $ .24 $ .23 $ .66 Basic earnings per share from discontinued operations -- -- -- .11 ------ ------ ------ ------ Basic earnings (loss) per share $ (.31) $ .24 $ .23 $ .77 ====== ====== ====== ====== Diluted earnings per share: Weighted average number of common shares outstanding 21,175 24,313 22,181 24,405 Dilutive shares applicable to stock options -- 223 306 211 ------ ------ ------ ------ Shares applicable to diluted earnings 21,175 24,536 22,487 24,616 ====== ====== ====== ====== Diluted earnings (loss) per share from continuing operations $ (.31) $ .24 $ .23 $ .66 Diluted earnings per share from discontinued operations -- -- -- .10 ------ ------ ------ ------ Diluted earnings (loss) per share $ (.31) $ .24 $ .23 $ .76 ====== ====== ====== ======