EXHIBIT 99.8

SCHEDULE OF EXHIBITS OMITTED PURSUANT TO INSTRUCTION 2 TO ITEM 601 OF
REGULATION S-K

Guaranty dated as of June 28, 1996, made by Singapore Telecommunications Ltd. to
Toronto Dominion (Texas), Inc., as Administrative Agent (substantially identical
in all material  respects to Exhibit 10.58 to the Company's  Quarterly Report on
Form 10-Q for the period ending June 30, 1996)

Guaranty  dated as of June 28, 1996,  made by Baron  Capital  Partners,  L.P. to
Toronto Dominion (Texas), Inc., as Administrative Agent (substantially identical
in all material  respects to Exhibit 10.58 to the Company's  Quarterly Report on
Form 10-Q for the period ending June 30, 1996)

Warrant No. 2 for the  Purchase of 625,000  Shares  (subject to  adjustment)  of
Common  Stock of  American  Mobile  Satellite  Corporation  issued to  Singapore
Telecommunications  Ltd.,  dated June 28, 1996  (substantially  identical in all
material  respects to Exhibit  10.59 to the Company's  Quarterly  Report on Form
10-Q for the period ending June 30, 1996)

Warrant No. 3 for the  Purchase of 625,000  Shares  (subject to  adjustment)  of
Common Stock of American Mobile  Satellite  Corporation  issued to Baron Capital
Partners,  L.P.,  dated June 28, 1996  (substantially  identical in all material
respects to Exhibit 10.59 to the Company's Quarterly Report on Form 10-Q for the
period ending June 30, 1996)