Serco Group plc (Serco), the FTSE 100 international service company, has completed the acquisition of SI International, Inc., a provider of information services, technology, and network solutions to the U. S. government, following the receipt of all regulatory approvals and satisfaction of customary closing conditions.

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 approximately US$422 million.

The deal Includs 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 December 31, 2008 on February 26, 2009.