# The 30 largest manufacturers in the Essonne department
Tamtam tracks 127 manufacturers headquartered in the Essonne department. This list ranks the 30 largest by number of employees on LinkedIn, led by RΓ©seau DEF, LFB and HORIBA France. Their median headcount is 234. Half of them were founded in 1978 or later. The most common headquarters are Les Ulis (6), Palaiseau (4) and Massy (3).
The Essonne department hosts a diverse range of manufacturing companies, from large established groups to mid-sized firms. Key players include RΓ©seau DEF, an international network specializing in fire safety systems, and LFB, which develops medicinal products for rare diseases. Other notable companies are ASN, a designer of optical submarine cable systems, and TechnicAtome, focused on compact nuclear reactor design.
The companies listed demonstrate a strong presence in specialized industrial sectors. There is a concentration of firms in high-tech manufacturing, such as HORIBA France in measuring instruments and Sebia in medical diagnostics. The data also shows a mix of industries, including automotive components with Eurostyle Systems, and food production with Moulins Soufflet.
π«π· Essonne Β· 30 companies Β· Updated Nov 11, 2026
| # | Company | Industry | Headquarters | Employees | Founded |
|---|---|---|---|---|---|
| 1 | [RΓ©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 | π«π· Massy | 3,484 | 1958 |
| 2 | [LFB](https://www.tamtam.ai/c/lfb) (groupe-lfb.com)
Develops, manufactures, and markets medicinal products for serious, often rare diseases in Hemostasis, Immunology, and Intensive Care, with a focus on plasma-derived products and biotechnologies. | Pharmaceutical Manufacturing | π«π· Les Ulis | 2,733 | 1994 |
| 3 | [HORIBA France](https://www.tamtam.ai/c/horiba-france) (horiba.com)
HORIBA France manufactures instruments to help individuals tackle all their challenges | Measuring and Control Instrument Manufacturing | π«π· Palaiseau | 2,200 | |
| 4 | [ASN](https://www.tamtam.ai/c/asn) (asn.com)
Designs, installs, and maintains global optical submarine cable systems for telecom, content providers, and offshore oil and gas industries. | Telecommunications | π«π· Les Ulis | 1,717 | 1994 |
| 5 | [TechnicAtome](https://www.tamtam.ai/c/technicatome) (technicatome.com)
Specialized in compact nuclear reactor design, construction, and maintenance for various sectors including naval propulsion, research, medicine, and energy | Defense and Space Manufacturing | π«π· Villiers-le-BΓ’cle | 1,467 | 1972 |
| 6 | [Eurostyle Systems](https://www.tamtam.ai/c/eurostyle-systems-les-ulis) (eurostyle-systems.fr)
Design and production of industrial solutions specializing in high-precision plastics processing and leather materials for global automotive markets across fourteen production sites. | Manufacturing | π«π· Les Ulis | 1,158 | 1964 |
| 7 | [HORIBA for Materials](https://www.tamtam.ai/c/horiba-for-materials) (horiba.com)
Researching, developing new materials, improving manufacturing, and implementing recycling solutions for sustainability across the material supply chain. | Research Services | π«π· Palaiseau | 1,053 | |
| 8 | [Sebia](https://www.tamtam.ai/c/sebia) (sebia.com)
Global specialty in vitro diagnostic leader for screening and monitoring various diseases, including oncology, diabetes, and autoimmunity. | Medical Equipment Manufacturing | π«π· Lisses | 1,018 | 1967 |
| 9 | [L-Acoustics](https://www.tamtam.ai/c/l-acoustics) (l-acoustics.com)
Leading manufacturer of professional sound solutions founded in 1984 near Paris, with presence in over 80 countries and specializing in modern line array technology and multichannel sound systems | Appliances, Electrical, and Electronics Manufacturing | π«π· Marcoussis | 700 | 1984 |
| 10 | [record portes automatiques](https://www.tamtam.ai/c/record-portes-automatiques) (recorddoors.com)
Designs, manufactures, installs, and maintains a wide range of automatic doors and related products for commercial and institutional sectors. | Wholesale Building Materials | π«π· Champlan | 523 | 1970 |
| 11 | [Vernet Group](https://www.tamtam.ai/c/vernet-group) (vernet-group.com)
Family company, world leader in thermal regulation, designing and manufacturing thermostats and thermostatic elements for automotive, heating, and plumbing industries. | Mechanical Or Industrial Engineering | π«π· Ollainville | 418 | 1927 |
| 12 | [Casio](https://www.tamtam.ai/c/casio) (casio.com)
Design and manufacture of consumer electronic products including watches, calculators, musical instruments, and other electronic devices for everyday use. | Appliances, Electrical, and Electronics Manufacturing | π«π· Palaiseau | 325 | 2002 |
| 13 | [Han](https://www.tamtam.ai/c/han) (han.fr)
Specializing in sourcing, creating, and marketing gift and souvenir products, as well as custom-designed promotional items with in-house branding and logistics services | Wholesale | π«π· Le Plessis-PΓ’tΓ© | 294 | 1982 |
| 14 | [Moulins Soufflet](https://www.tamtam.ai/c/moulins-soufflet) (moulins-soufflet.fr)
Designs sustainable, high-quality flours and specialties for artisan bakers, supporting agricultural transition and offering quality food respectful of tradition and environment. | Food and Beverage Manufacturing | π«π· Corbeil-Essonnes | 280 | 1978 |
| 15 | [Eurostyle Systems](https://www.tamtam.ai/c/eurostyle-systems) (eurostyle-systems.fr)
A branch of the GMD Group specializing in manufacturing automotive plastic components for OEMs and Tier 1 suppliers with 2500 employees and a turnover of 300 Mβ¬ in 2018 | Motor Vehicle Manufacturing | π«π· Les Ulis | 234 | 1964 |
| 16 | [Exotrail](https://www.tamtam.ai/c/exotrail) (exotrail.com)
Develops and operates propulsion systems, mission simulation software, and orbital transfer vehicles for efficient, sustainable space mobility, enabling telecommunication, Earth observation, space exploration. | Defense and Space Manufacturing | π«π· Massy | 215 | 2015 |
| 17 | [PMC Isochem](https://www.tamtam.ai/c/pmc-isochem) (pmcisochem.fr)
Custom manufacturing of APIs, intermediates, and excipients with drug delivery solutions including Vitamin E TPGS and amino acid polymers for pharmaceuticals. | Chemical Manufacturing | π«π· Vert-le-Petit | 215 | 2017 |
| 18 | [PCAS](https://www.tamtam.ai/c/pcas) (seqens.com)
Develops and produces complex molecules using advanced technologies for global leaders in Life Sciences and Innovative Technologies. Part of a larger international group. | Chemical Manufacturing | π«π· Longjumeau | 213 | 1962 |
| 19 | [UMS - United Monolithic Semiconductors](https://www.tamtam.ai/c/ums-united-monolithic-semiconductors) (ums-rf.com)
Designs and manufactures GaAs and GaN based RF and millimeter-wave integrated circuits and provides advanced foundry services for critical applications. | Semiconductor Manufacturing | π«π· Villebon-sur-Yvette | 210 | 1996 |
| 20 | [SOPHYSA](https://www.tamtam.ai/c/sophysa) (sophysa.com)
Develops neurosurgical implants, including adjustable valves for hydrocephalus and intracranial pressure monitoring systems, offering advanced solutions for neurological conditions. | Medical Equipment Manufacturing | π«π· Orsay | 195 | 1976 |
| 21 | [ADALTRA](https://www.tamtam.ai/c/adaltra) (adaltra.fr)
Specializing in communication systems for various environments such as offices, hotels, hospitals, airports, stadiums, and more, our solutions are designed by CAE GROUPE | Manufacturing | π«π· Massy | 182 | |
| 22 | [SIMP](https://www.tamtam.ai/c/simp) (simp.fr)
Specializing in plastic and rubber micro-injection molding, offering innovative solutions for various industries with automated production in France A leader in cosmetic applicator creation | Personal Care Product Manufacturing | π«π· Tigery | 182 | 1949 |
| 23 | [Toupret S.A](https://www.tamtam.ai/c/toupret-s-a) (toupret.com)
Manufacture and distribute ready-to-use wall preparation and decoration coatings for professionals and DIY enthusiasts across multiple international markets. | Wholesale Building Materials | π«π· Corbeil-Essonnes | 177 | 1938 |
| 24 | [Groupe Trouillet](https://www.tamtam.ai/c/groupe-trouillet) (groupe-trouillet.com)
Designs and manufactures industrial vehicle bodywork, offering tailored solutions from small trucks to semi-trailers, including comprehensive fleet management services and after-sales support. | Motor Vehicle Manufacturing | π«π· Morangis | 171 | 1957 |
| 25 | [JAULIN S.A.](https://www.tamtam.ai/c/jaulin-s-a) (jaulin.com)
Specialist in event engineering with a range of services including infrastructure, decorations, technical solutions, furniture rental, site management, and temporary structures | Events Services | π«π· Chilly-Mazarin | 135 | 1986 |
| 26 | [Composite Industrie S.A.](https://www.tamtam.ai/c/composite-industrie-s-a) (composite-industrie.com)
Specializes in manufacturing and repairing composite and hybrid metal-composite parts for aerospace, military, telecom, and transportation industries worldwide. | Aviation and Aerospace Component Manufacturing | π«π· Bondoufle | 128 | 1983 |
| 27 | [Elogen](https://www.tamtam.ai/c/elogen) (elogenh2.com)
Specialized technology provider designing, manufacturing, and maintaining hydrogen generators using water electrolysis with a focus on safety and meeting industry standards | Renewable Energy Equipment Manufacturing | π«π· Les Ulis | 127 | 2020 |
| 28 | [Sofradir](https://www.tamtam.ai/c/sofradir) (lynred.com)
Designs and manufactures high-quality infrared technologies for aerospace, defense, and commercial markets, including infrared detectors for military programs and commercial thermal imaging equipment. | Defense and Space Manufacturing | π«π· Palaiseau | 123 | 1986 |
| 29 | [BFR SYSTEMS](https://www.tamtam.ai/c/bfr-systems) (bfrsystems.com)
Design and supply of turnkey machines and production lines for food processing, packaging, handling, and quality control across multiple sectors. | Food and Beverage Manufacturing | π«π· Lisses | 122 | 1954 |
| 30 | [CELLforCURE by Seqens](https://www.tamtam.ai/c/cellforcure-by-seqens) (cellandgene.seqens.com)
Manufacturing advanced therapy medicinal products specializing in autologous and allogeneic cell and gene solutions through comprehensive end-to-end services from phase I to commercialization. | Biotechnology Research | π«π· Les Ulis | 112 | 2014 |
## 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.
## More company lists in the Essonne department
- [The largest companies in the Essonne department](https://www.tamtam.ai/l/largest-companies-essonne) (1,149)
- [Companies with in-house R&D in the Essonne department](https://www.tamtam.ai/l/r-and-d-companies-essonne) (198)
- [Multinational companies in the Essonne department](https://www.tamtam.ai/l/multinational-companies-essonne) (156)
- [Hardware manufacturers in the Essonne department](https://www.tamtam.ai/l/hardware-companies-essonne) (114)
- [Distributors and wholesalers in the Essonne department](https://www.tamtam.ai/l/distributors-and-wholesalers-essonne) (76)
- [IT Services and IT Consulting companies in the Essonne department](https://www.tamtam.ai/l/it-services-and-it-consulting-companies-essonne) (70)
- [Professional services firms in the Essonne department](https://www.tamtam.ai/l/professional-services-firms-essonne) (68)
- [Public sector organisations in the Essonne department](https://www.tamtam.ai/l/public-sector-organisations-essonne) (66)
- [Aerospace and defence companies in the Essonne department](https://www.tamtam.ai/l/aerospace-and-defense-companies-essonne) (65)
- [IT services companies in the Essonne department](https://www.tamtam.ai/l/it-services-companies-essonne) (60)
- [Retail chains in the Essonne department](https://www.tamtam.ai/l/retail-chains-essonne) (59)
- [Construction companies in the Essonne department](https://www.tamtam.ai/l/construction-companies-essonne) (56)
- [Software Development companies in the Essonne department](https://www.tamtam.ai/l/software-development-companies-essonne) (51)
- [Pharmaceutical companies in the Essonne department](https://www.tamtam.ai/l/pharmaceutical-companies-essonne) (45)
- [Electronics and semiconductor companies in the Essonne department](https://www.tamtam.ai/l/electronics-companies-essonne) (44)
- [Research institutes in the Essonne department](https://www.tamtam.ai/l/research-institutes-essonne) (42)
- [Events Services companies in the Essonne department](https://www.tamtam.ai/l/events-services-companies-essonne) (41)
- [SaaS companies in the Essonne department](https://www.tamtam.ai/l/saas-companies-essonne) (41)
- [Consulting firms in the Essonne department](https://www.tamtam.ai/l/consulting-firms-essonne) (40)
- [Family-owned companies in the Essonne department](https://www.tamtam.ai/l/family-owned-companies-essonne) (38)
- [Contract manufacturers in the Essonne department](https://www.tamtam.ai/l/contract-manufacturers-essonne) (35)
- [Research Services companies in the Essonne department](https://www.tamtam.ai/l/research-services-companies-essonne) (35)
- [Critical infrastructure operators in the Essonne department](https://www.tamtam.ai/l/critical-infrastructure-operators-essonne) (32)
- [Education providers in the Essonne department](https://www.tamtam.ai/l/education-companies-essonne) (30)
## The same list elsewhere in France
- [Manufacturers in France](https://www.tamtam.ai/l/manufacturers-france) (6,697)
- [Manufacturers in Γle-de-France](https://www.tamtam.ai/l/manufacturers-ile-de-france) (1,515)
- [Manufacturers in Auvergne-RhΓ΄ne-Alpes](https://www.tamtam.ai/l/manufacturers-auvergne-rhone-alpes) (1,216)
- [Manufacturers in Grand Est](https://www.tamtam.ai/l/manufacturers-grand-est) (573)
- [Manufacturers in Nouvelle-Aquitaine](https://www.tamtam.ai/l/manufacturers-nouvelle-aquitaine) (498)
- [Manufacturers in Pays de la Loire](https://www.tamtam.ai/l/manufacturers-pays-de-la-loire) (484)
- [Manufacturers in Occitanie](https://www.tamtam.ai/l/manufacturers-occitanie) (433)
- [Manufacturers in Provence-Alpes-CΓ΄te d'Azur](https://www.tamtam.ai/l/manufacturers-provence-alpes-cote-dazur) (394)
- [Manufacturers in Hauts-de-France](https://www.tamtam.ai/l/manufacturers-hauts-de-france) (369)
- [Manufacturers in the RhΓ΄ne department](https://www.tamtam.ai/l/manufacturers-rhone) (322)
- [Manufacturers in Brittany](https://www.tamtam.ai/l/manufacturers-brittany) (307)
- [Manufacturers in the Hauts-de-Seine department](https://www.tamtam.ai/l/manufacturers-hauts-de-seine) (285)
- [Manufacturers in Bourgogne-Franche-ComtΓ©](https://www.tamtam.ai/l/manufacturers-bourgogne-franche-comte) (272)
- [Manufacturers in Normandy](https://www.tamtam.ai/l/manufacturers-normandy) (245)
- [Manufacturers in Centre-Val de Loire](https://www.tamtam.ai/l/manufacturers-centre-val-de-loire) (207)
- [Manufacturers in the Nord department](https://www.tamtam.ai/l/manufacturers-nord) (204)
- [Manufacturers in the Bouches-du-RhΓ΄ne department](https://www.tamtam.ai/l/manufacturers-bouches-du-rhone) (187)
- [Manufacturers in the Isère department](https://www.tamtam.ai/l/manufacturers-isere) (178)
- [Manufacturers in the Haute-Garonne department](https://www.tamtam.ai/l/manufacturers-haute-garonne) (159)
- [Manufacturers in the Gironde department](https://www.tamtam.ai/l/manufacturers-gironde) (137)
- [Manufacturers in the Loire-Atlantique department](https://www.tamtam.ai/l/manufacturers-loire-atlantique) (125)
- [Manufacturers in the Loire department](https://www.tamtam.ai/l/manufacturers-loire) (122)
- [Manufacturers in the Bas-Rhin department](https://www.tamtam.ai/l/manufacturers-bas-rhin) (118)
- [Manufacturers in Paris](https://www.tamtam.ai/l/manufacturers-paris) (546)
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Source: https://www.tamtam.ai/l/manufacturers-essonne