# The 30 largest multinational companies in Massy
Tamtam tracks 30 multinational companies headquartered in Massy. This list ranks all of them by number of employees on LinkedIn, led by Carrefour, R茅seau DEF and Orano DS. Their median headcount is 97. Half of them were founded in 1996 or later.
The companies based in Massy operate across diverse sectors, including retail, nuclear energy, software development, and security. Most are mid-sized to large firms, with a strong presence of established corporations. Carrefour, a major retailer, operates grocery formats globally. Orano DS provides expertise in nuclear industrial logistics and waste management. Infovista develops data-driven solutions for network optimization. Secours Islamique France offers emergency aid and development programs worldwide.
A notable pattern is the concentration of companies in sectors related to infrastructure and services, such as security, IT, and real estate management. This suggests a local economy that supports both large-scale operations and specialized technical services.
馃嚝馃嚪 Massy 路 30 companies 路 Updated Nov 11, 2026
| # | Company | Industry | Headquarters | Employees | Founded |
|---|---|---|---|---|---|
| 1 | [Carrefour](https://www.tamtam.ai/c/carrefour) (carrefour.fr)
Operates grocery retail formats: hypermarkets, supermarkets, cash & carry, convenience stores. Major employer and local supply chain partner in over 30 countries. | Retail | 馃嚝馃嚪 Massy | 107,234 | |
| 2 | [R茅seau DEF](https://www.tamtam.ai/c/reseau-def) (reseau-def.com)
International network of expert companies providing detection, extinguishing, smoke extraction, and exit management systems through manufacturing and research facilities across several countries. | Appliances, Electrical, and Electronics Manufacturing | 馃嚝馃嚪 Massy | 3,484 | 1958 |
| 3 | [Orano DS](https://www.tamtam.ai/c/orano-ds) (orano.group)
Provides expertise and solutions to nuclear operators in industrial logistics, specialized maintenance, radiological safety, decommissioning, and waste management. | Nuclear Electric Power Generation | 馃嚝馃嚪 Massy | 2,118 | 2018 |
| 4 | [Carrefour Property](https://www.tamtam.ai/c/carrefour-property) (carrefourproperty.fr)
Property owner for hypermarkets and supermarkets in France, Spain, and Italy, managing over 4 million square meters across 1,000 European sites, partnering with Carmila for commercial centers. | Real Estate | 馃嚝馃嚪 Massy | 901 | 2009 |
| 5 | [Infovista](https://www.tamtam.ai/c/infovista) (infovista.com)
Empowers service providers and enterprises with data-driven solutions for optimizing network performance, enhancing customer experience, and driving business success. | Software Development | 馃嚝馃嚪 Massy | 834 | 1995 |
| 6 | [Secours Islamique France](https://www.tamtam.ai/c/secours-islamique-france) (secours-islamique.org)
Provides emergency aid, development programs, and social support in water, food security, child protection, and vulnerable populations worldwide. | Non-profit Organizations | 馃嚝馃嚪 Massy | 658 | 1991 |
| 7 | [Sector Alarm France](https://www.tamtam.ai/c/sector-alarm-france) (sectoralarm.fr)
Provides advanced alarm solutions and 24/7 security monitoring for residential and business clients across Europe with a focus on high customer satisfaction. | Security and Investigations | 馃嚝馃嚪 Massy | 434 | 2019 |
| 8 | [Weesure](https://www.tamtam.ai/c/weesure) (weesure.com)
Surveillance, fire safety, and protection services through audits and electronic security for healthcare, military, industrial, and retail sectors to prevent various risks. | Security and Investigations | 馃嚝馃嚪 Massy | 374 | |
| 9 | [HTDS](https://www.tamtam.ai/c/htds) (htds.fr)
Specialized distribution and maintenance of advanced detection systems for various applications in France and international markets. | Wholesale Import and Export | 馃嚝馃嚪 Massy | 265 | 2002 |
| 10 | [CODRA](https://www.tamtam.ai/c/codra) (codra.net)
Specializing in industrial IT, our company offers automation and test system services while also developing and distributing software solutions for various industries | Software Development | 馃嚝馃嚪 Massy | 181 | 1986 |
| 11 | [iObeya](https://www.tamtam.ai/c/iobeya) (iobeya.com)
Transforms physical workspaces into immersive, collaborative digital environments for sharing KPIs, plans, and ideas, fostering collective intelligence and quick decision-making. | Software Development | 馃嚝馃嚪 Massy | 156 | 2011 |
| 12 | [CA CONSUMER FINANCE](https://www.tamtam.ai/c/ca-consumer-finance) (ca-cf.fr)
A financial services company based in France, specializing in consumer finance solutions | Financial Services | 馃嚝馃嚪 Massy | 123 | |
| 13 | [KYOCERA Document Solutions France](https://www.tamtam.ai/c/kyocera-document-solutions-france) (kyoceradocumentsolutions.fr)
Provide comprehensive document management solutions including software, hardware, and professional services to support digital transformation and reduce environmental impact. | IT Services and IT Consulting | 馃嚝馃嚪 Massy | 113 | 1959 |
| 14 | [GSDI - Expert en Cosm茅tique Urbaine](https://www.tamtam.ai/c/gsdi-expert-en-cosmetique-urbaine) (gsdi.fr)
Provides innovative, eco-friendly urban surface treatments including adhesive films, protective coatings, and decorative solutions for various industries. | Retail Office Equipment | 馃嚝馃嚪 Massy | 98 | 1993 |
| 15 | [HTDS S没ret茅 & D茅tection](https://www.tamtam.ai/c/htds-surete-and-detection) (htds.fr)
A multinational company specializing in high-tech security and product inspection equipment for airports, ports, law enforcement, industries, and other organizations | Wholesale Import and Export | 馃嚝馃嚪 Massy | 97 | 2002 |
| 16 | [CERC (Cardiovascular European Research Center)](https://www.tamtam.ai/c/cerc-cardiovascular-european-research-center) (cerc-europe.org)
A leading European CRO founded by experienced physicians, specializing in clinical research, innovative techniques, and supporting young scientific leaders globally | Research Services | 馃嚝馃嚪 Massy | 84 | 2008 |
| 17 | [L枚wenstein Medical France](https://www.tamtam.ai/c/lowenstein-medical-france) (loewensteinmedical.com)
Development and supply of reliable respiratory assistance devices for hospitals and home care, focusing on patient quality of life and support. | Medical Equipment Manufacturing | 馃嚝馃嚪 Massy | 72 | 1996 |
| 18 | [APDRA Pisciculture Paysanne](https://www.tamtam.ai/c/apdra-pisciculture-paysanne) (apdra.org)
A French NGO promoting sustainable fish farming in developing countries, enhancing food security, resource diversification, and empowering rural communities through training and awareness | Civic and Social Organizations | 馃嚝馃嚪 Massy | 65 | 1996 |
| 19 | [Gewiss France](https://www.tamtam.ai/c/gewiss-france) (gewiss.com)
An international leader in low-voltage electrical systems and components for residential, commercial, and industrial sectors, offering lighting solutions and EV charging infrastructure | Appliances, Electrical, and Electronics Manufacturing | 馃嚝馃嚪 Massy | 58 | 1970 |
| 20 | [SCP Europe](https://www.tamtam.ai/c/scp-europe) (scpeurope.com)
Distribution of pool, spa, sauna, and leisure products across Europe with extensive inventory and customer-focused service for business growth. | Wholesale | 馃嚝馃嚪 Massy | 55 | |
| 21 | [Hamamatsu Photonics France](https://www.tamtam.ai/c/hamamatsu-photonics-france) (hamamatsu.com)
Manufactures optoelectronic components, modules, and systems covering the entire optical spectrum for demanding applications in medical, automotive, science, environmental, analytical, and industrial processes. | Semiconductor Manufacturing | 馃嚝馃嚪 Massy | 49 | 1985 |
| 22 | [Cuenod](https://www.tamtam.ai/c/cuenod) (cuenod.com)
With over 120 years of experience, this European burner manufacturer offers a wide range of environmentally-friendly heating solutions for residential, commercial, and industrial applications | Machinery Manufacturing | 馃嚝馃嚪 Massy | 46 | 1899 |
| 23 | [Aryason Consulting](https://www.tamtam.ai/c/aryason-consulting) (aryason.fr)
Massy based firm specialized in providing professional advice on computer systems and software solutions with seven years of industry experience. | Software Development | 馃嚝馃嚪 Massy | 26 | 2013 |
| 24 | [SpotLight Earth](https://www.tamtam.ai/c/spotlight-earth) (spotlight-earth.com)
Strategic partner for CCS planning and surveillance, delivering innovative technology solutions for onshore and offshore carbon capture and storage projects worldwide. | Environmental Services | 馃嚝馃嚪 Massy | 25 | 2017 |
| 25 | [A.W. Faber-Castell France](https://www.tamtam.ai/c/a-w-faber-castell-france) (faber-castell.fr)
A German family-owned company founded in 1761, manufacturing high-quality pencils, fine art products, and personalized writing instruments with global distribution | Consumer Goods | 馃嚝馃嚪 Massy | 19 | 1990 |
| 26 | [OPTOPRIM France](https://www.tamtam.ai/c/optoprim-france) (optoprim.com)
Wholesale company operating in Vanves, France, specializing in optical products and accessories | Wholesale | 馃嚝馃嚪 Massy | 14 | 1994 |
| 27 | [Mead Johnson Nutrition - France](https://www.tamtam.ai/c/mead-johnson-nutrition-france) (nutramigen.fr)
Specializes in infant nutrition focused on combating cow's milk protein allergies to improve health and well-being of infants. | Pharmaceutical Manufacturing | 馃嚝馃嚪 Massy | 11 | |
| 28 | [Adents](https://www.tamtam.ai/c/adents) (antaresvisiongroup.com)
A leading provider of serialization solutions for product identification and traceability in the pharmaceutical industry, helping companies comply with regulations | Software Development | 馃嚝馃嚪 Massy | 11 | 2007 |
| 29 | [GE DIGITAL SERVICES EUROPE](https://www.tamtam.ai/c/ge-digital-services-europe) (ge.com)
A company in Europe specializing in digital services for industrial challenges, including renewable energy, emissions reduction, productivity, demand adaptation, and team safety | Software Development | 馃嚝馃嚪 Massy | 8 | |
| 30 | [HUB Parking Technology FR](https://www.tamtam.ai/c/hub-parking-technology-fr) (hubparking.fr)
Innovative parking technology company: develops, installs, and supports Parking Access and Revenue Control Systems worldwide Offers scalable solutions with remote management capabilities | IT Services and IT Consulting | 馃嚝馃嚪 Massy | 5 | 2015 |
## How this list is built
Every company on this list has a Tamtam company profile. The industry is the one the company gives on LinkedIn; categories such as SaaS or fintech are classified by Tamtam's AI from the company's website and LinkedIn page; and the headquarters city must match the company's own address. Companies are ranked by the number of employees on LinkedIn, and the list is refreshed every night. Classifications can be wrong, so treat the list as a starting point rather than an official ranking. Last updated Nov 11, 2026.
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Source: https://www.tamtam.ai/l/multinational-companies-massy