MDA Adopts Shareholder Rights Plan

Richmond, B.C. - MacDonald, Dettwiler and Associates Ltd. (TSX: MDA), a provider of essential information solutions, announced today that its Board of Directors has adopted a Shareholder Rights Plan (the 'Rights Plan'). The Rights Plan, which takes effect today, has been adopted to ensure the fair treatment of shareholders in the event of any take-over offer for the company's common shares.

The Rights Plan is not intended to prevent take-over bids that treat shareholders fairly. Bids that meet certain requirements intended to protect the interests of all shareholders are deemed to be 'Permitted Bids' under the Rights Plan. Permitted Bids are offers to acquire common shares of the company made by way of a take-over circular and which must, among other requirements described in the Rights Plan, remain open for at least 60 days.

The company is not adopting the Rights Plan in response to, or in anticipation of, any specific take-over bid or proposal to acquire control of the company. The Rights Plan is similar to plans adopted by other Canadian companies. The full text of the Rights Plan is available on the SEDAR website at http://www.sedar.com

The Rights Plan has conditionally been approved by the Toronto Stock Exchange and is subject to ratification by the company's shareholders at the next meeting of shareholders. If ratified by shareholders, the Rights Plan will expire at the termination of the company's annual meeting in 2011, unless extended upon reconfirmation by shareholders at that meeting. Subsequently, the Rights Plan must be reconfirmed by shareholders at every third annual meeting of the company thereafter.

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 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 Statements

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.