Inmarsat Introduces Data Capability for IsatPhone Pro

Handheld Satellite Phone Offers up to 20kbps Data Globally

WASHINGTON, DC, March 16, 2011 - Inmarsat (LSE:ISAT), the leading provider of global mobile satellite
communications services, today announced the availability of a data service
on its global handheld satellite phone, IsatPhone Pro.

The new circuit-switched data capability, offering an effective data rate
of up to 20kbps, will be provided in the next firmware upgrade to the handset
on 31st March 2011.

"IsatPhone Pro is ideally suited for use as a data service," said Drew
Brandy, Director of Land Services at Inmarsat. "The handset design means the
IsatPhone Pro can be simply placed on its side with the antenna deployed for
connection to the satellite while a micro USB cable connects it to a laptop.
And the Inmarsat-4 satellites on which the service runs are, of course,
designed specifically to handle data communications.

"We are very pleased with the performance of IsatPhone Pro's data
capability. It is proving to be very robust whether using generic or
customised applications. In testing we have actually exceeded 20kbps
throughput with plain text email on several occasions. It's ideal for those
people wanting to access emails, jpegs, documents or PDFs," he said.

In addition to the data capability, the next firmware upgrade for
IsatPhone Pro will feature a number of service enhancements.

"IsatPhone Pro has achieved a great deal since it was launched barely
nine months ago: winning an award for innovation, gathering fantastic reviews
and being used in every single country in which satellite communications is
authorised," said Drew. "But, as today's announcement shows, we don't stop
looking for ways to enhance the service for our end users. We expect this new
data capability to be very well received."

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: John Warehand, PR Manager, Inmarsat, Tel: +44(0)20-7728-1579, Mob: +44(0)7739-778-128, Email: john_warehand at inmarsat.com