June 8, 2005, Detroit, MI, USA

Fluent Inc., the worldwide leader in Computational Fluid Dynamics (CFD) software and services, previewed its new CFD software "FLUENT for CATIA" to attendees at the annual CFD Summit in Detroit, Michigan today. The product is scheduled for release in late 2005, with final prototypes to be demonstrated at the European CATIA Forum on October 4 - 6th in Frankfurt, Germany. Additional demonstrations of FLUENT for CATIA will be made at the European Automotive CFD Conference (EACC) on June 29 - 30th in Frankfurt, Germany, where Fluent and Dassault Systèmes will jointly present the benefits of integrated analysis in the automotive PLM environment.

"We want to make it easier for our customers to predict product performance," said Severin Lafranchi, Dassault Systemes' R&D Director for CATIA Simulation. "The open SIMULIA scientific platform, based on CAA V5 architecture, enables focused applications like FLUENT to be used much earlier in the engineering process by many more engineers. Fluent has created a fully PLM-integrated CFD solution that reveals the effects of fluid dynamics during product design. The result will be better performing, more cost effective products in less time. We are excited to team with Fluent, among the industry leaders in CFD, to bring this unique and innovative product to market."

Commenting on this major step forward for the CFD Industry, Paul Bemis, Vice President of Marketing at Fluent Inc said, "In contrast to other approaches, the FLUENT for CATIA solution operates completely within the native CATIA data structures. The key benefit of this unique implementation is full associativity with all upstream operations allowing functionality such as analysis driven design optimization to be utilized in the first release. By embedding FLUENT, a major analysis CFD code into the popular CATIA V5 infrastructure, we allow users the ability and flexibility to carry out Product Lifecycle Management all within one workflow."

Fully embedded in CATIA V5, FLUENT for CATIA combines the worlds most widely used and powerful CFD code, FLUENT 6.2, with the leading CATIA V5 PLM software environment from Dassault Systèmes. Fully associative to the PLM data structures, FLUENT for CATIA provides fluid flow analysis in the CATIA working environment and is a dramatic step forward for the use of CFD in the design process. It will allow engineers, especially in the automotive and aerospace industries, to achieve significant product design improvements and cost savings. The software will help engineers test conceptual designs at the earliest possible stages of the product development cycle in a PLM workflow environment. The unified design and analysis process provided by FLUENT for CATIA leads to improved product quality, faster time to market, and reductions in large downstream manufacturing costs.

The FLUENT for CATIA product provides automated tools for geometry conditioning, flow volume creation, meshing, the CFD solution process, and report generation. The product exposes the CFD analysis process within the familiar environment of the CATIA interface. FLUENT for CATIA is fully upwardly compatible with the vast array of turbulence, physics, chemistry, and multiphase models in FLUENT V6.2. FLUENT for CATIA V1.0 will handle steady state, single-phase, laminar and turbulent non-reacting flows, with a range of heat transfer options for incompressible or mildly compressible flow physics. The software will therefore model flows in ducts, pipes and manifolds, external aerodynamics, heat exchangers and HVAC systems, architectural designs and cabin ventilation models, as well as engine cooling and automotive powertrain applications.

FLUENT for CATIA is being beta tested currently and is planned to be available by the end of 2005 from local Fluent Offices and Distributors worldwide. The software is owned, supported and managed by Fluent Inc.

2005 European Automotive CFD Conference (EACC): http://www.eacc.fluent.com

2005 European CATIA Forum: http://www.ecforum.com

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About Fluent

Fluent is the world's largest provider of computational fluid dynamics (CFD) software and consulting services. Fluent's software is used for simulation, visualization, and analysis of fluid flow, heat and mass transfer, and chemical reactions. It is a vital part of the computer-aided engineering (CAE) process for companies around the world and is deployed in nearly every manufacturing industry. Using Fluent's software, product development, design and research engineers build virtual prototypes and simulate the performance of proposed and existing designs, allowing them to improve design quality while reducing cost and speeding time to market. Fluent's corporate headquarters are located in Lebanon, New Hampshire, USA, with offices in Belgium, England, France, Germany, India, Italy, China, Japan and Sweden. Its CFD software is also available around the world through joint ventures, partnerships, and distributors in Korea, Australia, Brazil, China, Taiwan, the Czech Republic, Middle East, and most European countries.

FLUENT® is a registered trademark of Fluent Inc.

For more information, contact:

Jennifer Correa Fluent Inc. 10 Cavendish Court Lebanon, NH 03766 (603) 643-2600 Ext. 668 jrc@fluent.com

About Dassault Systèmes

(NASDAQ: DASTY; Euronext Paris: #13065, DSY.PA)

As world leader in three-dimensional product lifecycle management (PLM) solutions, the Dassault Systemes group brings value to more than 55,000 customers in 80 countries. A pioneer in the 3D software market since 1981, Dassault Systemes develops and markets 3D PLM application software and services that support industrial processes and provide a 3D vision of the entire life cycle of products from conception to retirement. Its offering includes 3D PLM integrated solutions for product development (CATIA, ENOVIA, DELMIA, SMARTEAM), general-use 3D solutions (SolidWorks), and 3D components (SPATIAL). Dassault Systemes is listed on the Nasdaq (DASTY) and Euronext Paris (#13065, DSY.PA) stock exchanges. Information about Dassault Systemes is available at http://www.3ds.com.

For more information, contact:

Press Contacts: Anthony Maréchal + 33 (0)1 55 49 84 21 anthony_marechal@ds-fr.com

Investor Contacts: Emma Rutherford, Harriet Keen Financial Dynamics + 44 207 831 3113