Serco Completes Acquisition of SI International

Serco Completes Acquisition of SI International

30 December 2008

Acquisition Broadens Federal Government Customer Base and Service Offerings

Serco Group plc (Serco) today announces that it has completed the acquisition
of SI International, Inc. (NASDAQ:SINT), a provider of information services,
technology, and network solutions to the US government, following the receipt
of all regulatory approvals and satisfaction of customary closing conditions.

SI International will be combined with Serco's existing North American business
and will enhance Serco's ability to deliver integrated solutions to the US$290
billion US federal government services market, with:

  * Scale and increased resources to bid on larger US government contracts.
    Serco North America and SI International will have combined annual revenue
    of $1.3 billion and approximately 11,500 employees.
   
  * Depth of capabilities to enhance Serco North America's offerings,
    encompassing information technology, professional services, human capital
    management, engineering and logistics, national security, and intelligence.
   
  * Access to higher growth areas, such as improved information sharing, cyber
    security, systems engineering, program management, business process
    reengineering and homeland security.
   
  * New customer relationships. With Serco North America and SI International
    having highly complementary customer bases, the combined company now serves
    every branch of the military, numerous federal civilian agencies, and the
    intelligence community. Major customers include: US Army, US Air Force, US
    Navy, Department of Homeland Security, Department of State, US Federal
    Aviation Administration, Federal Retirement Thrift Investment Board, US
    Postal Service, and the intelligence community.
   
Under the terms of the definitive merger agreement, Serco acquired SI
International for $32 per share in cash, valuing its fully diluted share
capital at US$422 million. Including the assumption of SI International's net
debt, the consideration values SI International at US$524 million. The
acquisition, which was financed from multi-currency bank facilities, is
expected to be accretive to Serco's Adjusted earnings in its first full year of
ownership, and its returns are expected to meet Serco's cost of capital in the
third full year of ownership. Serco will announce its preliminary results for
the full year ending 31 December 2008 on 26 February 2009.

Serco Group Chief Executive Christopher Hyman said: "We are delighted to
welcome the employees of SI International to Serco. In the US, Serco is a
leading supplier to the substantial US federal services market. We now have a
stronger platform from which we will be able to offer our customers more
integrated solutions and deliver robust growth for our shareholders."

For further information please contact Serco Group plc: [phone]

Charles King, Head of Investor Relations

Marcus De Ville, Head of Media Relations

www.serco.com

Notes to Editors

About Serco

Serco is an international service company which combines commercial know-how
with a deep public service ethos. We improve services by managing people,
processes, technology and assets more effectively. We advise policy makers,
design innovative solutions, integrate systems and - most of all - deliver to
the public. Serco supports governments, agencies and companies who seek a
trusted partner with a solid track record of providing assured service
excellence. Our people offer operational, management and consulting expertise
in the aviation, defence, education, health, home affairs, local government,
science, technology, transport and the commercial sectors. More information can
be found at www.serco.com.

About Serco North America

Serco North America is a leading provider of professional, technology, and
management services focused on the federal government. We advise, define,
develop, integrate, deliver, and maintain solutions that transform how clients
achieve their missions. Our agility, customer-first approach, robust portfolio
of services, and global experience enable us to quickly respond with solutions
that achieve outcomes with value. Headquartered in Reston, Virginia, Serco
North America has approximately 11,500 employees and annual revenue of US$1.3
billion, and is part of Serco Group, a US$5 billion international business that
has helped transform government and public services around the world. More
information can be found at www.serco-na.com.