SUPPLEMENTAL NON-GAAP FINANCIAL INFORMATION

Non-GAAP – Adjusted IFRS SUMMARY RECONCILIATION

(in millions of Euro, except per share data, unaudited)

Readers are cautioned that the supplemental non-GAAP and adjusted IFRS information presented in this press release is subject to inherent limitations. It is not based on any comprehensive set of accounting rules or principles and should not be considered as a substitute for U.S. GAAP or IFRS measurements. Also, our supplemental non-GAAP and adjusted IFRS financial information may not be comparable to similarly titled non-GAAP and adjusted IFRS measures used by other companies. Further specific limitations for individual non-GAAP and adjusted IFRS measures, and the reasons for presenting non-GAAP and adjusted IFRS financial information, are set forth in today’s press release with respect to other operating income and expense, net and in the Company’s annual report for the year ended December 31, 2007 on Form 20-F filed with the SEC on April 4, 2008 and in the Document de Référence filed with the AMF on April 4, 2008 for the other non-GAAP and adjusted IFRS financial measures. To compensate for these limitations, the supplemental non-GAAP and adjusted IFRS financial information should be read not in isolation, but only in conjunction with our consolidated financial statements prepared in accordance with U.S. GAAP and IFRS.

DASSAULT SYSTEMES