1 EXHIBIT 11. STATEMENT RE: COMPUTATION OF EARNINGS PER SHARE THREE-MONTH PERIOD ENDED DECEMBER 31, 1998 ASSUMING BASIC DILUTION (2) ----------------------- ------------------ Weighted average of outstanding shares 36,885,745 36,885,745 Common equivalent shares: Outstanding stock options N/A 1,094,486 Other potentially dilutive securities: Convertible Notes (1) N/A 3,571,429 ----------------------- ------------------ Shares used in computing net income per common share 36,885,745 41,551,660 ======================= ================== Net income $ (19,551,000) $(19,551,000) Adjustments assuming dilution: Interest expense adjustment, net of applicable taxes N/A 1,198,000 ----------------------- ------------------ Net income $ (19,551,000) $(18,353,000) ======================= ================== Net income per common share ($0.53) ($0.53) ======================= ================== YEAR ENDED DECEMBER 31, 1998 ASSUMING BASIC DILUTION (2) ------------------ ------------------ Weighted average of outstanding shares 35,624,888 35,624,888 Common equivalent shares: Outstanding stock options N/A 1,140,270 Other potentially dilutive securities: Convertible Notes (1) N/A 3,571,429 ------------------ ------------------ Shares used in computing net income per common share 35,624,888 40,336,587 ================== ================== Net income $ (6,372,000) $ (6,372,000) Adjustments assuming dilution: Interest expense adjustment, net of applicable taxes N/A 2,682,000 ------------------ ------------------ Net income $ (6,372,000) $ (3,690,000) ================== ================== Net income per common share $ (0.18) $ (0.18) ================== ================== Notes: (1)- On September 16, 1997, the company sold $100 million of 5% convertible subordinated notes due October 2002. The notes are convertible at the option of the holders into Orbital common stock at a conversion price of $28.00 per share. (2)- Subsidiary stock options that enable holders to obtain subsidiary's common stock pursuant to effective stock option plans are included in computing the subsidiary's earnings per share, to the extent dilutive. Those earnings per share data are included in the company's per share computations based on the company's holdings of the subsidiary's stock. For the three months and year ended December 31, 1998, all such subsidiary stock options were anti-dilutive.