Exhibit 11 UNISOURCE ENERGY CORPORATION COMPUTATION OF EARNINGS PER SHARE Years Ended December 31, 1998 1997 1996 ------ ------ ------ - Thousands of Dollars - (except per share data) Basic Earnings Per Share: Numerator: Net Income $28,032 $83,572 $120,852 Denominator: Average Shares of Common Stock - Outstanding 32,178 32,138 32,136 ------ ------ ------- Basic Earnings Per Share $ 0.87 $ 2.60 $ 3.76 ====== ====== ======= Diluted Earnings Per Share: Numerator: Net Income $28,032 $83,572 $120,852 Denominator: Average Shares of Common Stock - Outstanding 32,178 32,138 32,136 Effect of Dilutive Securities: Warrants 79 53 81 Options 90 87 36 ------ ------ ------- Total Shares 32,347 32,278 32,253 ------ ------ ------- Diluted Earnings Per Share $ 0.87 $ 2.59 $ 3.75 ====== ====== ======= Options to purchase 460,000 shares of common stock at $16.25 per share were outstanding at the end of the year 1998 but were not included in the computation of diluted EPS because the options' exercise price was greater than the average market price of the common shares. 4.6 million of the 7.6 million warrants outstanding are exercisable into TEP common stock. See Note 13. However, the dilutive effect is the same as it would be if the warrants were exercisable into UniSource Energy Common Stock.