MDA Provides Update On Home Information Pack Sign-Up By Independent Estate Agents In UK

Richmond, B.C. - MacDonald, Dettwiler and Associates Ltd. (TSX: MDA), a provider of essential information solutions, announced today that the average sign-up rate for MDA's Home Information Pack (HIP) service by independent estate agent offices has accelerated recently, as the June 1, 2007 compulsion date is drawing closer.

In the first half of 2006, MDA announced that it had entered into alliances with three large Estate Agent Associations who were seeking to offer a white label HIP service to their members: National Homes Network, Homelink Network of the National Association of Estate Agents, and The Guild of Professional Estate Agents.

As of March 20, 2007 MDA has entered into agreements with 474 independent estate agency offices belonging to these associations. The average sign-up rate has been around 30 offices per week recently, representing a major acceleration since January. Of those offices signing with MDA, approximately 65% are committing all or the majority of their HIP volumes to MDA. The remainder represents registrations without specified volume commitment levels.

These sign-ups represent predominantly independent estate agent offices that do not belong to the top-50 estate agencies and who have decided to buy HIPs through their association's membership services.

About MDA

MDA provides advanced information solutions that capture and process vast amounts of data, produce essential information, and improve the decision making and operational performance of business and government organizations worldwide.

Focused on markets and customers with strong repeat business potential, MDA delivers a broad spectrum of earth and space based information solutions, ranging from complex operational systems, to tailored information services, to electronic information products.

MDA employs more than 3,000 people in locations across the United States, the United Kingdom, and Canada. The Company's common shares trade on the Toronto Stock Exchange under the symbol TSX:MDA.

Related Websites:
www.mdacorporation.com

Forward-Looking Statement

This release contains forward-looking statements and information, which reflect the current view of MacDonald, Dettwiler and Associates Ltd. with respect to future events and financial performance. Any such forward-looking statements are subject to risks and uncertainties and MDA's actual results of operations could differ materially from historical results or current expectations. Additional information on these and other potential factors that could affect MDA's financial results are detailed in documents filed from time to time with the applicable Canadian securities regulatory authorities.

The Toronto Stock Exchange has neither approved nor disapproved the form or content of this release.