# 30 leading professional services firms in the Bouches-du-Rhône department

Tamtam tracks 249 professional services firms headquartered in the Bouches-du-Rhône department. This list ranks the 30 largest by number of employees on LinkedIn, led by Onet SA, Ortec Group and Catering International & Services CIS. Their median headcount is 428. Half of them were founded in 2003 or later. The most common headquarters are Marseille (17), Aix-en-Provence (7) and Vitrolles (3).

This list features large and mid-sized professional services firms in the Bouches-du-Rhône department, primarily focused on industrial support, engineering, and IT consulting. Companies like Onet SA, a family service group, Ortec Group, providing multidisciplinary industrial services, and Catering International & Services CIS, offering integrated services for remote sites, are prominent. Onet Technologies specializes in nuclear engineering, while Klanik provides IT engineering consulting.

The data shows a strong concentration of headquarters in Marseille, with several companies also based in Aix-en-Provence and Vitrolles. The firms cover a range of services from facilities management and environmental solutions to complex IT and engineering projects, indicating a diverse yet interconnected professional services landscape in the region.

🇫🇷 Bouches-du-Rhône · 30 companies · Updated Nov 12, 2026

| # | Company | Industry | Headquarters | Employees | Founded |
|---|---|---|---|---|---|
| 1 | [Onet SA](https://www.tamtam.ai/c/onet-sa) (groupeonet.com)<br>A family service group with 74,000 employees in 8 countries, offering a wide range of services including cleaning, security, engineering, and maintenance | Business Consulting and Services | 🇫🇷 Marseille | 14,750 | 1860 |
| 2 | [Ortec Group](https://www.tamtam.ai/c/ortec-group) (ortec-group.com)<br>Provides multidisciplinary services for industry, energy, and environment, including maintenance, new works, environmental services, facilities management, logistics, and engineering consulting. | Environmental Services | 🇫🇷 Aix-en-Provence | 4,388 |  |
| 3 | [Catering International & Services CIS](https://www.tamtam.ai/c/catering-international-and-services-cis) (cis-integratedservices.com)<br>Providing integrated services and turnkey solutions ensuring well-being and safety for residents in remote offshore and onshore project sites worldwide. | Accommodation and Food Services | 🇫🇷 Marseille | 2,899 | 1992 |
| 4 | [Onet Technologies](https://www.tamtam.ai/c/onet-technologies) (onet.fr)<br>Expertise in nuclear engineering and services for reactor maintenance, dismantling, decommissioning, waste management, and training within the nuclear industry lifecycle. | Industrial Machinery Manufacturing | 🇫🇷 Marseille | 2,071 |  |
| 5 | [Onet Propreté et Services](https://www.tamtam.ai/c/onet-proprete-et-services) (onet.fr)<br>Maintaining hygiene and cleanliness in various environments, including workplaces, public spaces, and transport areas, ensuring they are clean, healthy, and pleasant. | Facilities Services | 🇫🇷 Marseille | 2,038 |  |
| 6 | [ATEXIS](https://www.tamtam.ai/c/atexis) (atexis.com)<br>Innovates sustainable, secure technology, assisting customers with operations and maintenance of complex systems across various sectors like aerospace and defense. | IT Services and IT Consulting | 🇫🇷 Vitrolles | 809 | 2011 |
| 7 | [GROUPE ETIC](https://www.tamtam.ai/c/groupe-etic) (etic-groupe.com)<br>Outsourced reception services, event staffing, physical security monitoring, customer relationship management via call centers, and professional fire safety audit and training programs. | Events Services | 🇫🇷 Marseille | 636 | 1994 |
| 8 | [Groupe ACCEO \| BET Energie, Ascenseur, Environnement, AMO & MOE Spécialisées](https://www.tamtam.ai/c/groupe-acceo-bet-energie-ascenseur-environnement-amo-and-moe-specialisees) (acceo.eu)<br>Providing specialized engineering consulting for buildings, focusing on elevators, energy efficiency, environment, and project management to optimize operations and reduce costs. | Engineering Services | 🇫🇷 La Ciotat | 569 | 2003 |
| 9 | [Sonovision - Ortec Group](https://www.tamtam.ai/c/sonovision-ortec-group) (sonovisiongroup.com)<br>Experts process complex systems content, enriching products with innovative solutions throughout their lifecycle, from design to technical content and training for optimized field operations. | Engineering Services | 🇫🇷 Aix-en-Provence | 568 |  |
| 10 | [Klanik](https://www.tamtam.ai/c/klanik) (klanik.com)<br>Provides IT engineering consulting, assisting partners with digital and technological projects, leveraging expert talent across various technological verticals globally for digital transformation. | IT Services and IT Consulting | 🇫🇷 Marseille | 548 | 2011 |
| 11 | [Onet Accueil](https://www.tamtam.ai/c/onet-accueil) (onet.fr)<br>The company specializes in providing reception services that are both pleasant and useful, facilitating efficient connections between different stakeholders on site | Events Services | 🇫🇷 Marseille | 483 |  |
| 12 | [Key Performance Consulting (KPC)](https://www.tamtam.ai/c/key-performance-consulting-kpc) (keyperformance-consulting.com)<br>Global player in upstream and integration phases for systems, offering technology consulting and services for large project integration and business process improvement. | IT Services and IT Consulting | 🇫🇷 Aix-en-Provence | 474 | 2010 |
| 13 | [TPF INGENIERIE](https://www.tamtam.ai/c/tpf-ingenierie) (tpf-i.fr)<br>An engineering company specializing in Building, Infrastructure, Water/Environment, Energy/Maintenance sectors with a collaborative and innovative approach to project development | Engineering Services | 🇫🇷 Marseille | 470 | 1957 |
| 14 | [setec international](https://www.tamtam.ai/c/setec-international) (inter.setec.fr)<br>Engineering consultancy specializing in transport infrastructure projects including feasibility, design, environmental studies, and project management across France and internationally. | Civil Engineering | 🇫🇷 Vitrolles | 446 |  |
| 15 | [CMR Group](https://www.tamtam.ai/c/cmr-group) (cmr-group.com)<br>Specializing in sensors and automation systems for diesel engines, CMR offers control solutions in energy, industry, and marine sectors, focusing on sustainability and ethical practices | Automation Machinery Manufacturing | 🇫🇷 Marseille | 428 | 1959 |
| 16 | [Interway](https://www.tamtam.ai/c/interway) (interway.fr)<br>Managed IT services including outsourcing, network integration, payment solutions, interactive digital systems, and extensive support for diverse sectors nationwide. | IT Services and IT Consulting | 🇫🇷 Vitrolles | 398 | 1993 |
| 17 | [iQanto](https://www.tamtam.ai/c/iqanto) (iqanto.net)<br>Industrial transformation through automation, robotics, AI, and cybersecurity to improve processes and deploy intelligent systems across diverse sectors for small and large enterprises. | IT Services and IT Consulting | 🇫🇷 Marseille | 349 |  |
| 18 | [Chambre de Commerce et d'Industrie Marseille-Provence](https://www.tamtam.ai/c/chambre-de-commerce-et-d-industrie-marseille-provence) (cciamp.com)<br>Provides business support services and infrastructure development for 115,000 local companies while promoting regional economic competitiveness and digital transformation in standard international markets. | Government Administration | 🇫🇷 Marseille | 336 |  |
| 19 | [Home-Services](https://www.tamtam.ai/c/home-services) (home-services.com)<br>Home Services provides home assistance in the Var, Bouches du Rhône, and Vaucluse regions, offering services like childcare, elderly care, housekeeping, and more | Individual and Family Services | 🇫🇷 Marseille | 331 | 1997 |
| 20 | [SEA TPI](https://www.tamtam.ai/c/sea-tpi) (seatpi.com)<br>ESN specializing in IT operations, offering services in supervision, system administration, cybersecurity, and support Constantly hiring various IT professionals nationwide Visit website for job opportunities | IT Services and IT Consulting | 🇫🇷 La Ciotat | 321 | 1996 |
| 21 | [ECP - Project Management .INtelligence](https://www.tamtam.ai/c/ecp-project-management-intelligence) (assystem.com)<br>Project Management Consulting Group specializing in Oil & Gas, Nuclear, Energy, Defense, Infrastructures, Chemistry, Metallurgy sectors Services include project management, cost estimation, risk management, and more | Business Consulting and Services | 🇫🇷 Aix-en-Provence | 287 |  |
| 22 | [l'Escale](https://www.tamtam.ai/c/l-escale) (lescale.io)<br>A platform offering a professional break tailored for parents, with a 8-week online program to guide them towards finding a job that suits them | Professional Training and Coaching | 🇫🇷 Marseille | 286 | 2019 |
| 23 | [PMSm](https://www.tamtam.ai/c/pmsm) (pmsm.fr)<br>French leader in medical assistance for industrial and tertiary environments, offering outsourced medical staff, emergency medical services, prevention programs, and biomedical engineering solutions | Medical Practices | 🇫🇷 Aix-en-Provence | 282 | 1994 |
| 24 | [OCEANCALL](https://www.tamtam.ai/c/oceancall) (oceancall.co)<br>OceanCall is an independent and innovative outsourcing company offering flexible, personalized solutions for customer relations and data processing to boost growth and enhance customer interactions | IT Services and IT Consulting | 🇫🇷 Aix-en-Provence | 272 | 2004 |
| 25 | [Altereo](https://www.tamtam.ai/c/altereo) (altereo.fr)<br>An independent French company driving clients from ideas to behaviors, specializing in water engineering, public utility management, city sustainability, and geographic intelligence solutions | Environmental Services | 🇫🇷 Venelles | 229 | 1989 |
| 26 | [Seres Technologies](https://www.tamtam.ai/c/seres-technologies) (seres-technologies.com)<br>Specializes in risk management, complex systems design, and R&D, supporting industries like mobility, defense, and energy with comprehensive safety and security solutions. | Business Consulting and Services | 🇫🇷 Marseille | 220 | 2009 |
| 27 | [Job Link](https://www.tamtam.ai/c/job-link) (joblink.fr)<br>A specialist recruitment agency in France with 16 branches, offering selective and efficient recruitment services to clients and connecting candidates with desired jobs | Human Resources Services | 🇫🇷 Marseille | 219 | 2005 |
| 28 | [ARKADIA Group](https://www.tamtam.ai/c/arkadia-group) (arkadiagroup.fr)<br>ARKADIA Group is an independent engineering and services firm specializing in Energy and Aerospace/Transport sectors, offering expertise in large industrial projects worldwide | Business Consulting and Services | 🇫🇷 Aix-en-Provence | 214 | 2010 |
| 29 | [FATEC Group](https://www.tamtam.ai/c/fatec-group) (fatec-group.com)<br>A leading independent fleet management company in France, providing transparent services for a range of clients, with expertise in responsible mobility | Business Consulting and Services | 🇫🇷 Marseille | 204 | 2013 |
| 30 | [Apave Sudeurope SAS](https://www.tamtam.ai/c/apave-sudeurope-sas)<br>An individual & family services company based in Marseille, France, offering a variety of services to support individuals and families | Individual and Family Services | 🇫🇷 Marseille | 203 |  |

## 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 12, 2026.

## More company lists in the Bouches-du-Rhône department

- [The largest companies in the Bouches-du-Rhône department](https://www.tamtam.ai/l/largest-companies-bouches-du-rhone) (3,317)
- [Multinational companies in the Bouches-du-Rhône department](https://www.tamtam.ai/l/multinational-companies-bouches-du-rhone) (351)
- [Companies with in-house R&D in the Bouches-du-Rhône department](https://www.tamtam.ai/l/r-and-d-companies-bouches-du-rhone) (320)
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- [Manufacturers in the Bouches-du-Rhône department](https://www.tamtam.ai/l/manufacturers-bouches-du-rhone) (187)
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- [IT services companies in the Bouches-du-Rhône department](https://www.tamtam.ai/l/it-services-companies-bouches-du-rhone) (155)
- [IT Services and IT Consulting companies in the Bouches-du-Rhône department](https://www.tamtam.ai/l/it-services-and-it-consulting-companies-bouches-du-rhone) (154)
- [SaaS companies in the Bouches-du-Rhône department](https://www.tamtam.ai/l/saas-companies-bouches-du-rhone) (145)
- [Hardware manufacturers in the Bouches-du-Rhône department](https://www.tamtam.ai/l/hardware-companies-bouches-du-rhone) (142)
- [Family-owned companies in the Bouches-du-Rhône department](https://www.tamtam.ai/l/family-owned-companies-bouches-du-rhone) (142)
- [Consulting firms in the Bouches-du-Rhône department](https://www.tamtam.ai/l/consulting-firms-bouches-du-rhone) (129)
- [Software Development companies in the Bouches-du-Rhône department](https://www.tamtam.ai/l/software-development-companies-bouches-du-rhone) (120)
- [Education providers in the Bouches-du-Rhône department](https://www.tamtam.ai/l/education-companies-bouches-du-rhone) (119)
- [Business Consulting and Services companies in the Bouches-du-Rhône department](https://www.tamtam.ai/l/business-consulting-and-services-companies-bouches-du-rhone) (113)
- [Real Estate companies in the Bouches-du-Rhône department](https://www.tamtam.ai/l/real-estate-companies-bouches-du-rhone) (109)
- [Healthcare providers in the Bouches-du-Rhône department](https://www.tamtam.ai/l/healthcare-providers-bouches-du-rhone) (107)
- [Law Practice companies in the Bouches-du-Rhône department](https://www.tamtam.ai/l/law-practice-companies-bouches-du-rhone) (100)
- [Critical infrastructure operators in the Bouches-du-Rhône department](https://www.tamtam.ai/l/critical-infrastructure-operators-bouches-du-rhone) (98)
- [Accounting firms in the Bouches-du-Rhône department](https://www.tamtam.ai/l/accounting-firms-bouches-du-rhone) (93)
- [Accounting companies in the Bouches-du-Rhône department](https://www.tamtam.ai/l/accounting-companies-bouches-du-rhone) (92)
- [Construction companies in the Bouches-du-Rhône department](https://www.tamtam.ai/l/construction-companies-bouches-du-rhone) (91)
- [Higher Education companies in the Bouches-du-Rhône department](https://www.tamtam.ai/l/higher-education-companies-bouches-du-rhone) (83)

## The same list elsewhere in France

- [Professional services firms in France](https://www.tamtam.ai/l/professional-services-firms-france) (6,610)
- [Professional services firms in Île-de-France](https://www.tamtam.ai/l/professional-services-firms-ile-de-france) (3,377)
- [Professional services firms in Auvergne-Rhône-Alpes](https://www.tamtam.ai/l/professional-services-firms-auvergne-rhone-alpes) (711)
- [Professional services firms in the Hauts-de-Seine department](https://www.tamtam.ai/l/professional-services-firms-hauts-de-seine) (629)
- [Professional services firms in Provence-Alpes-Côte d'Azur](https://www.tamtam.ai/l/professional-services-firms-provence-alpes-cote-dazur) (433)
- [Professional services firms in the Rhône department](https://www.tamtam.ai/l/professional-services-firms-rhone) (400)
- [Professional services firms in Occitanie](https://www.tamtam.ai/l/professional-services-firms-occitanie) (399)
- [Professional services firms in Grand Est](https://www.tamtam.ai/l/professional-services-firms-grand-est) (316)
- [Professional services firms in Nouvelle-Aquitaine](https://www.tamtam.ai/l/professional-services-firms-nouvelle-aquitaine) (308)
- [Professional services firms in Hauts-de-France](https://www.tamtam.ai/l/professional-services-firms-hauts-de-france) (260)
- [Professional services firms in Pays de la Loire](https://www.tamtam.ai/l/professional-services-firms-pays-de-la-loire) (253)
- [Professional services firms in the Haute-Garonne department](https://www.tamtam.ai/l/professional-services-firms-haute-garonne) (208)
- [Professional services firms in the Nord department](https://www.tamtam.ai/l/professional-services-firms-nord) (178)
- [Professional services firms in Brittany](https://www.tamtam.ai/l/professional-services-firms-brittany) (167)
- [Professional services firms in the Loire-Atlantique department](https://www.tamtam.ai/l/professional-services-firms-loire-atlantique) (158)
- [Professional services firms in the Gironde department](https://www.tamtam.ai/l/professional-services-firms-gironde) (151)
- [Professional services firms in Normandy](https://www.tamtam.ai/l/professional-services-firms-normandy) (114)
- [Professional services firms in the Yvelines department](https://www.tamtam.ai/l/professional-services-firms-yvelines) (108)
- [Professional services firms in the Ille-et-Vilaine department](https://www.tamtam.ai/l/professional-services-firms-ille-et-vilaine) (94)
- [Professional services firms in Paris](https://www.tamtam.ai/l/professional-services-firms-paris) (2,241)
- [Professional services firms in Lyon](https://www.tamtam.ai/l/professional-services-firms-lyon) (265)
- [Professional services firms in Toulouse](https://www.tamtam.ai/l/professional-services-firms-toulouse) (139)
- [Professional services firms in Marseille](https://www.tamtam.ai/l/professional-services-firms-marseille) (123)
- [Professional services firms in Boulogne-Billancourt](https://www.tamtam.ai/l/professional-services-firms-boulogne-billancourt) (102)

## The same list elsewhere

- [Professional services firms in the world](https://www.tamtam.ai/l/professional-services-firms-in-the-world) (24,737)
- [Professional services firms in Europe](https://www.tamtam.ai/l/professional-services-firms-in-europe) (13,698)

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Source: https://www.tamtam.ai/l/professional-services-firms-bouches-du-rhone