The Seine-Maritime department hosts a mix of established companies and institutions with a focus on in-house research and development. This includes large entities like Sidel, which provides packaging equipment, and CHU de Rouen, a major hospital network. Mid-sized firms such as Novacel, specializing in protective films, and Alpha Maintenance, offering engineering services for the oil and energy sector, also feature.
The data shows a diverse industrial base. For example, Groupe Nutriset and Nexira are active in food and beverage manufacturing, with the former focused on nutritional products and the latter on natural ingredients. ESIGELEC is a higher education institution, while SOGET provides IT services for port community systems, indicating a blend of manufacturing, healthcare, education, and technology sectors.
| # | Company | Employees | |||
|---|---|---|---|---|---|
| 1 | 6,370 | ||||
| 2 |
CHU de Rouenchu-rouen.fr
Large hospital network providing patient care, medical education, and research, supporting regional healthcare and training future health professionals. |
3,823 | |||
| 3 |
Novacelnovacel-solutions.com
Provides technical films, tapes, papers, and machines to protect and preserve material surfaces across various industrial market segments. |
390 | |||
| 4 |
ESIGELEC : ÉCOLE D'INGÉNIEURS-ES GÉNÉRALISTESesigelec.fr
Specializing in general engineering education, the company offers various programs in Intelligent and Connected Systems, emphasizing project-based learning, internships, entrepreneurship, and innovation for over 10,000 graduates |
341 | |||
| 5 |
Alpha Maintenancealpha.fr
Company specializing in oil and energy sector, providing services and solutions based in Port-de-Bouc, France. |
333 | |||
| 6 |
Groupe Nutrisetgroupenutriset.fr
Research, production, and distribution of nutritional products to treat and prevent malnutrition among vulnerable populations worldwide. |
246 | |||
| 7 |
Les Ateliers du Goûtles-ateliers-du-gout.fr
Production of homemade-style French recipes for professional restaurateurs, emphasizing quality, teamwork, and regional manufacturing workshops. |
212 | |||
| 8 |
Pressalitpressalit.com
A Danish company producing high-quality toilet seats, accessible bathrooms, and height-adjustable kitchens for people with reduced mobility since 1954 |
211 | |||
| 9 |
Nexiranexira.com
Family-owned company, world leader acacia gum, global leader natural ingredients, botanical extracts, food, nutrition, dietary supplements, clean label. |
200 | |||
| 10 |
Abysse Corp Groupabyssecorp.com
Design, manufacture, and distribute licensed pop culture merchandise including manga, cinema, video games, with global offices and multiple product lines. |
192 | |||
| 11 | 171 | ||||
| 12 |
Générale de Manutention Portuairegmportuaire.fr
Leading French port handling company managing container terminals, exceptional cargo, refrigerated container repair, and inland transport with eco-friendly, digitalized operations. |
127 | |||
| 13 |
LEADERleader-group.company
Designs, manufactures, and supplies advanced firefighting and rescue equipment including ventilation fans, fire hoses, thermal cameras, and victim search devices worldwide. |
127 | |||
| 14 | 125 | ||||
| 15 |
SERAPID Groupserapid.com
Leading provider of Rigid Chain technology for heavy linear motion in industries like kinetic architecture, nuclear, medical, aerospace, automotive, and more worldwide |
119 | |||
Want more companies than this list?This page shows the largest ones only. Connect to Tamtam to see every company that matches, filter by size, industry or growth, and reach their decision-makers. | |||||
| 16 |
2H ENERGY2henergy.fr
Specialized in energy systems, providing design, manufacturing, installation, and maintenance services for various sectors including military, nuclear, oil and gas, telecommunications, and healthcare |
111 | |||
| 17 |
Institut national des Sciences appliquées de Roueninsa-rouen.fr
It is a prominent engineering school in Normandy, offering diverse programs, conducting research, and fostering strong industry partnerships for future engineers. |
101 | |||
| 18 |
Compagnie Fluviale de Transportsogestran.com
A company that specializes in French barging services and operates as a shipping operator as well |
96 | |||
| 19 | 93 | ||||
| 20 |
DEFION Security NLdefion.security
Provides independent, full-service cybersecurity to reduce risk, ensure compliance, and strengthen resilience, connecting prevention, detection, and response with strategic advisory and research. |
92 | |||
| 21 |
ARLANXEO ELASTOMERES FRANCE SASarlanxeo.fr
Development, manufacturing, and marketing of high-performance synthetic rubber for automotive, tire, construction, oil, and gas industries across multiple countries. |
89 | |||
| 22 |
Trace Softwaretrace-software.com
Global leader in CAD & CAE software for industrial engineering, specializing in electrical design Empowering electrical solutions for manufacturing, energy, and transportation industries |
85 | |||
| 23 |
PAUMIERpaumier-sa.fr
Design and manufacture of tailored HVAC and refrigerating systems for marine and offshore sectors, including air handling and cooling equipment. |
82 | |||
| 24 |
Polytechspolytechs.fr
Production of masterbatches, compounds, and additive blends for plastics industry, serving polymer producers to recycling companies worldwide. |
71 | |||
| 25 |
ROUSSEAU - identité visuellerousseau-sa.fr
An environmentally conscious industrial player specializing in urban furniture, signage, metal structures, and facades for prestigious clients, offering a complete product lifecycle approach |
69 | |||
| 26 |
CELEC - Electronics specialistcelec.fr
Design and manufacture of custom electronic automation solutions and sensors for diverse industries, serving global markets with high-quality products. |
69 | |||
| 27 |
MILLBÄKER SASmillbaker.com
Design and manufacture of ingredient solutions for wheat-flour-bread sector, including flour correctors, bakery improvers, and fermented sourdoughs. |
63 | |||
| 28 |
Robocathrobocath.com
A French medtech company specializes in developing and commercializing robotic solutions for treating cardiovascular diseases, focusing on precision and interventional conditions improvement |
59 | |||
| 29 |
Groupe SUMPARsumpar.com
specializes in supplying complex metal parts and assemblies for aerospace, offering design, machining, quality control, and assembly services |
52 | |||
| 30 |
EcoTechnilineco-technilin.com
Industrial design and manufacture of technical materials from natural fibers like flax and hemp for advanced composite applications across multiple global markets. |
47 | |||
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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 13, 2026.
More company lists in the Seine-Maritime department
- The largest companies in the Seine-Maritime department 918
- Retail chains in the Seine-Maritime department 97
- Multinational companies in the Seine-Maritime department 89
- Manufacturers in the Seine-Maritime department 72
- Public sector organisations in the Seine-Maritime department 65
- Distributors and wholesalers in the Seine-Maritime department 53
- Professional services firms in the Seine-Maritime department 51
- Critical infrastructure operators in the Seine-Maritime department 46
- Family-owned companies in the Seine-Maritime department 44
- IT services companies in the Seine-Maritime department 40
- Hardware manufacturers in the Seine-Maritime department 38
- Education providers in the Seine-Maritime department 36
- Healthcare providers in the Seine-Maritime department 34
- Logistics companies in the Seine-Maritime department 34
- Financial services firms in the Seine-Maritime department 32
- IT Services and IT Consulting companies in the Seine-Maritime department 30
- Real Estate companies in the Seine-Maritime department 30
- Higher Education companies in the Seine-Maritime department 28
- Software Development companies in the Seine-Maritime department 28
- Government Administration companies in the Seine-Maritime department 27
- Industrial Machinery Manufacturing companies in the Seine-Maritime department 27
- Consulting firms in the Seine-Maritime department 26
- Hospitals and Health Care companies in the Seine-Maritime department 25
The same list elsewhere in France
- Companies with in-house R&D in France 8,748
- Companies with in-house R&D in Île-de-France 2,695
- Companies with in-house R&D in Auvergne-Rhône-Alpes 1,459
- Companies with in-house R&D in Occitanie 680
- Companies with in-house R&D in Grand Est 640
- Companies with in-house R&D in Provence-Alpes-Côte d'Azur 612
- Companies with in-house R&D in Nouvelle-Aquitaine 566
- Companies with in-house R&D in the Hauts-de-Seine department 510
- Companies with in-house R&D in the Rhône department 509
- Companies with in-house R&D in Pays de la Loire 480
- Companies with in-house R&D in Hauts-de-France 410
- Companies with in-house R&D in Brittany 366
- Companies with in-house R&D in the Haute-Garonne department 323
- Companies with in-house R&D in the Bouches-du-Rhône department 320
- Companies with in-house R&D in the Isère department 304
- Companies with in-house R&D in Bourgogne-Franche-Comté 261
- Companies with in-house R&D in the Nord department 237
- Companies with in-house R&D in Normandy 227
- Companies with in-house R&D in the Gironde department 225
- Companies with in-house R&D in the Loire-Atlantique department 207
- Companies with in-house R&D in the Essonne department 198
- Companies with in-house R&D in Centre-Val de Loire 195
- Companies with in-house R&D in Paris 1,249
- Companies with in-house R&D in Lyon 192