BBN CORPORATION EXHIBIT 11.1 COMPUTATION OF NET LOSS PER SHARE (000's except per-share data) Three Months Ended ____________________________________________ September 30, 1995 September 30, 1994 ___________________ ___________________ Fully Fully Primary Diluted Primary Diluted ________ _______ _______ _______ Weighted average shares outstanding 17,518 17,518 16,614 16,614 Incremental shares from use of treasury stock method for stock options (a) (a) (a) (a) ________ ________ ________ ________ Shares used in per-share calculations 17,518 17,518 16,614 16,614 ======== ======== ======== ======== Net loss $(8,651) $(8,651) $(1,808) $(1,808) ======== ======== ======== ======== Net loss per share $ (.49) $ (.49) $ (.11) $ (.11) ======== ======== ======== ======== (a) Incremental shares were not used as their effect would be antidilutive.