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                                                                    EXHIBIT 99.1

PRESS RELEASE                                     EMBARGO UNTIL JANUARY 27, 2000
                                                                    AT 7:00 A.M.

           TELEGLOBE AND ORBITAL STRENGTHEN COMMITMENT TO ORBCOMM WITH
                     NEW OWNERSHIP AND FINANCING AGREEMENT

   ORBCOMM PARTNERS AGREE TO PROVIDE NEW EQUITY TO FUND ORBCOMM'S OPERATIONS
                     AND IMPROVE ITS FINANCIAL FLEXIBILITY

(MONTREAL, QC AND DULLES, VA, JANUARY 27, 2000) - Teleglobe Inc. (NYSE, TSE:
TGO) and Orbital Sciences Corporation (NYSE: ORB) announced today that they have
agreed to restructure their partnership governing the financing and ownership of
ORBCOMM Global, L.P. (ORBCOMM), the world's first commercial provider of global
wireless data communications services through a network of 35 satellites
operating in low-Earth orbit.

As a result of this agreement and previous capital infusions, ORBCOMM's equity
will increase by over US$100 million, mostly due to the conversion of certain
payables to Orbital and Teleglobe. Also as a result of this agreement, which has
been approved by the companies' respective Boards of Directors, Teleglobe
becomes the majority owner and sole general partner of ORBCOMM.

"This agreement enables ORBCOMM to continue its rapid growth and capitalize on
the market leadership it has established at a time when significant progress is
being made in a significant number of industry segments worldwide. As a
strategic investor, Teleglobe intends to continue to provide equity financing to
ORBCOMM, which is also actively pursuing opportunities for third party equity in
the partnership," said Claude Seguin, Executive Vice President, Finance, and
Chief Financial Officer of Teleglobe. "While Teleglobe maintains its focus on
its Internet strategy and GlobeSystem investment, we believe this agreement will
allow Teleglobe to enhance the value of its investment in ORBCOMM," added Mr.
Seguin.

Mr. David W. Thompson, Orbital's Chairman and Chief Executive Officer, said,
"Orbital has been, and will continue to be, fully committed to the success of
ORBCOMM. We will continue to actively participate in ORBCOMM's business
activities, but without the need for further capital investments on our part if
we so choose. Through this agreement, we are carrying out our long-standing
strategy of maintaining a very significant ownership stake in the high-growth
and high-margin potential of ORBCOMM and our other satellite services ventures,
such as ORBIMAGE and ORBNAV. Our equity position in ORBCOMM and these other
start-up companies is complemented by our space and ground infrastructure and
satellite access products sectors that provide us with growing revenues and
earnings. By eliminating our share of the future capital requirements for
ORBCOMM, this agreement significantly eases our cash needs as we aim to generate
improved financial results in 2000," added Mr. Thompson. "I am delighted by the
partners' continuing commitment to ORBCOMM and the enhanced strength of the
business as a result of this agreement. We believe this agreement enables us to
accelerate our growth and deliver on the growing market demand for ORBCOMM
services," said Mr. Scott L. Webster, Chairman and Chief Executive Officer of
ORBCOMM.

ORBCOMM provides two-way monitoring, tracking and messaging services through the
world's first commercial low-Earth orbit satellite-based data communications
system. ORBCOMM applications include tracking of mobile assets such as trailers,
containers, rail cars, heavy equipment, fishing vessels, barges and government
assets; monitoring of fixed assets such as


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electric utility meters, oil and gas storage tanks, wells and pipelines and
environmental projects; and messaging services for consumers and commercial and
government entities. For more information, visit www.orbcomm.com.

Teleglobe is a leading global provider of broadband services with the most
extensive global Internet network. Delivering advanced broadband applications to
customers in more than 100 countries - matching global reach with global depth -
Teleglobe is the premier communications architecture for the digital economy.
Teleglobe is currently enhancing its leadership position through
GLOBESYSTEM(TM), a 5 year, US$5 billion strategic initiative providing 160
cities around the world with scalable broadband service platforms, and linking
them through a seamless data network. GLOBESYSTEM is the world's first globally
integrated Internet, voice, data and video network. For more information, visit
www.teleglobe.com.

Orbital is one of the largest space technology and satellite services companies
in the world, with 1999 revenues targeted to exceed $900 million. The company,
which is headquartered in Dulles, Virginia, employs over 5,200 people at its
major facilities in the United States, Canada and several overseas locations.
Orbital is the world's leading manufacturer of low-cost space systems and
products, including satellites, launch vehicles, electronics and sensors,
satellite ground systems and software, and satellite-based navigation and
communications products. Through its ORBCOMM and ORBIMAGE affiliates and ORBNAV
subsidiary, Orbital is also a pioneering operator of satellite-based networks
that provide data communications, high-resolution imagery and automotive
information services to customers around the world. For more information, visit
http://www.orbital.com.

For more information:



TELEGLOBE INC.                               ORBITAL SCIENCES CORPORATION
                                          

Michele Beaubien                             Barron Beneski
Vice President, Corporate Communications     Vice President, Corporate Communications
Tel. 514-868-7762                            Tel. 703-406-5528
Email. michele.beaubien@teleglobe.com        Email. beneski.barron@orbital.com

Nicole Blanchard                             Tim Perrott
Director, Investor Relations                 Vice President of Investor Relations
Tel. 514-868-8148                            Tel. 703-406-5997
Email. nicole.blanchard@teleglobe.com        Email. perrott.tim@orbital.com