Inmarsat Makes New North American Team Appointments

LONDON, April 11, 2011 - Inmarsat (LSE: ISAT), the leading provider of global mobile satellite
communications services, today announced two new appointments to its North
American teams.

David Helfgott becomes President of Inmarsat, Inc and Head of Business
Development, Americas and Peter Hadinger joins Inmarsat Global XpressTM as
President of Inmarsat Government Services Inc (IGSI). Both will be based at
Inmarsat's Washington DC office.

David Helfgott will be responsible for external representation of
Inmarsat Inc, and will head strategy and business development in the
Americas.

Comments Rupert Pearce, SVP Inmarsat Enterprises: "I am delighted to
welcome David to the Inmarsat team and look forward to his contribution. With
Leo Mondale now leading our Global Xpress Ka-band programme after seven very
successful years at the helm of our North American business development
capability, David's arrival to our Washington DC office ensures that we
maintain the highest skills in business development. With David's exceptional
industry experience, particularly regarding US Government needs, I am sure we
will quickly benefit from his influence and extensive knowledge."

David Helfgott was previously President of Cobham Surveillance Group, CEO
of SES Americom Government Services, and President and CEO of Datapath Inc.
He holds a BA from the University of Virginia and an MBA from the Darden
School at University of Virginia.

Leo Mondale, Managing Director of Inmarsat GX welcomed the appointment of
Peter Hadinger:

"As a respected satellite engineer and business development executive at
Northrop Grumman and TRW, Peter has a deep understanding of satcom solutions
for a broad range of government missions. He has developed government markets
for technology and services for decades. Peter brings to Inmarsat extensive
experience in national security and a unique perspective as a government
contractor on how to better integrate our services into the government
systems of the future."

In his role at Northrop Grumman, Peter Hadinger led a number of
long-range technology and systems initiatives, supporting air-space
integration, cyber, international and regulatory efforts across the company.

He served as Vice-Chair of the FCC's WRC-07 Advisory Committee
and Vice-Chair of the Satellite Task Force for the US President's National
Security Telecom Advisory Commission. He is a member of the executive board
and past chairman of the Satellite Industry Association and served as a
Brookings Congressional Fellow in the U.S. Senate.

Peter Hadinger received his BSEEE from California State
Polytechnic University, an MBA with emphasis in finance and strategic
planning from George Mason University and serves on engineering advisory
boards at Virginia Tech.

About Inmarsat

Inmarsat plc (LSE: ISAT) is the leading provider of global
mobile satellite communications services. Since 1979, Inmarsat has been
providing reliable voice and high-speed data communications to governments,
enterprises and other organizations, with a range of services that can be
used on land, at sea or in the air. The company's services are delivered
through a global network of more than 400 distribution partners and service
providers operating in 100 countries. For the year ended 31 December 2010,
Inmarsat plc had total revenue of US$1,171.6 million (2009: US$1,038.1
million) with an EBITDA of US$696.1 million (2009: US$594.2 million). For
more information, please visit www.inmarsat.com.

Media Contacts: Chris McLaughlin, Vice President, External Affairs, Inmarsat, Tel No: +44(0)7796-276033, Email: chris_mclaughlin at inmarsat.com; Neville Rawlings, On behalf of Inmarsat, Bell Pottinger Public Relations, Tel: +44(0)20-7861-2502, Email: nrawlings at bell-pottinger.co.uk