EXHIBIT I
JOINT FILING AGREEMENT
In accordance with Rule 13d-1(k) under the Securities Exchange Act of
1934, as amended, the persons named below agree to the joint filing on behalf of
each of them of a statement on Schedule 13D dated April 13, 1999 with respect to
the Common Stock, par value $.01 per share, of American Mobile Satellite
Corporation, a Delaware corporation. This Joint Filing Agreement shall be
included as an Exhibit to such joint filing. In evidence thereof each of the
undersigned, being duly authorized, hereby executes this Agreement this 13th day
of April 1999.
SINGAPORE TELECOMMUNICATIONS LTD.
By: /s/ Hoh Wing Chee
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Name: Hoh Wing Chee
Title: VP (International Network)
TEMASEK HOLDINGS (PRIVATE) LTD.
By: /s/ Ng Xxx Xxxx
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Name: Ng Xxx Xxxx
Title: Senior Vice President/
Company Secretary
