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50 leading professional services firms in Brittany

Tamtam tracks 167 professional services firms headquartered in Brittany. This list ranks the 50 largest by number of employees on LinkedIn, led by Groupe SAMSIC, Keyrus and Interaction Interim. Their median headcount is 192. Half of them were founded in 1986 or later. The most common headquarters are Rennes (13), Cesson-Sévigné (3) and Brest (2).

🇫🇷 Brittany50 companiesUpdated Nov 11, 2026

The professional services firms in Brittany include a mix of business consulting, IT services, and accounting firms. Groupe SAMSIC offers tailored solutions in facility management and HR services. Keyrus focuses on reliable intelligence foundations and performance steering. Interaction Interim provides temporary work and recruitment services. Groupe Cogedis offers accounting, management, legal, and HR consultancy.

Several companies in the list, such as Groupe SAMSIC, Interaction Interim, and RBI, are based in Rennes or nearby Cesson-Sévigné, indicating a cluster of professional services activity in this area. ABER Propreté and NET PLUS specialize in cleaning and facilities services.

#CompanyIndustryHeadquarters EmployeesFounded
1
Groupe SAMSICsamsic.com

With over 30 years of experience, we prioritize human and professional values while offering tailored solutions in facility management and HR services

Business Consulting and Services 🇫🇷 Cesson-Sévigné 6,680 1986
2
Keyruskeyrus.com

Architects reliable intelligence foundations, human-in-command governance, and performance steering to operationalize intelligence for adaptive, resilient, continuously improving organizations.

IT Services and IT Consulting 🇫🇷 Levallois-Perret 2,020 1996
3
Interaction Interiminteraction-interim.com

National network providing temporary work, recruitment for fixed-term and permanent contracts, training, support, and consulting services across all business sectors.

Staffing and Recruiting 🇫🇷 Rennes 1,055 1991
4
Groupe Cogedis - Comptabilité et conseil aux entreprisescogedis.com

Providing accounting, management, legal, and human resources consultancy services alongside strategic wealth management and environmental advice for professionals and agricultural business owners.

Accounting 🇫🇷 Saint-Thonan 783 1970
5
ABER Propretéaberproprete.fr

Providing high-quality industrial cleaning and hygiene services with continuous employee training and precise service monitoring since 1975.

Environmental Services 🇫🇷 Saint-Jacques-de-la-Lande 682 1975
6
NET PLUSnet-plus.fr

A company specializing in cleaning services, prioritizing customer satisfaction, quality interventions, and social responsibility with a focus on employee well-being and respect

Facilities Services 🇫🇷 Cesson-Sévigné 521 1990
7
RBIrbi-informatique.fr

Specializing in information systems design, implementation, and integration, RBI-Informatique offers services in infrastructure, collaboration, and management solutions for businesses

IT Services and IT Consulting 🇫🇷 Rennes 468 1981
8
Ouest Conseilsouestconseils.bzh

Providing accounting, audit, and strategic management consulting for Breton businesses, managing payroll and digital transition to ensure client success and local growth.

Accounting 🇫🇷 Quimper 450 1988
9
Office Notarial Anastasia Moreaumoreau-fougeres.notaires.fr

Located in the heart of Fougères, this company offers legal services in real estate, family, and corporate law, focusing on accessibility, listening, and modernity

Legal Services 🇫🇷 Fougères 447 n/a
10
LMCOlmco.fr

provides up-to-date information and resources on business law, fiscal policies, social regulations, and commercial real estate for companies

Construction 🇫🇷 Langueux 402 n/a
11
Cerfrance Côtes d'Armorcerfrance22.fr

Leading accounting and consulting firm providing strategic support, financial expertise, and social management services for small businesses, farmers, artisans, and independent professionals.

Accounting 🇫🇷 Plérin 313 1955
12
Geirecgeirec.com

An independent regional cabinet with a national focus, GEIREC supports businesses with expertise and values, offering daily partnership, confidentiality, competence, and responsiveness

Accounting 🇫🇷 Rennes 308 1979
13
SPCservicepro-bretagne.com

This company specializes in industrial automation and robotics, supporting integrators and manufacturers in their projects with expert guidance.

Automation Machinery Manufacturing 🇫🇷 Parthenay-de-Bretagne 277 2016
14
CAPEOScapeos.fr

Provides comprehensive accounting, legal, and tax services alongside audit, wealth management, and IT solutions for companies across diverse sectors through local offices.

Accounting 🇫🇷 Rennes 266 1979
15
Igam Expertise Comptableigam.fr

Accounting and advisory network serving 6000 clients across various sectors with 35 offices and 300 professionals in western France.

Accounting 🇫🇷 Lamballe 266 1986
16
VIRAGE CONSEILvirageconseil.com

Specializes in business development, sales growth, professional training, and commercial animation with a strong presence in telemarketing and merchandising.

International Trade and Development 🇫🇷 262 1993
17
QUARTAquarta.fr

Precision measurement and 3D modeling for urban and rural spaces Creating high value projects through expertise in surveying, urban engineering, and VRD design

Civil Engineering 🇫🇷 Saint Jacques de la Lande 259 1982
18
SCC Raising Places' Valuesscc.fr

Manages, transforms, and invents unique living spaces, focusing on strategic and operational services to increase the value of properties for clients and partners.

Leasing Non-residential Real Estate 🇫🇷 Paris 233 1962
19
Groupe Creativegroupe-creative.fr

Works with clients on IT and digital transformation projects, offering expertise in consulting, creation, development, research, and innovation across various digital domains.

IT Services and IT Consulting 🇫🇷 Rennes 232 2008
20
Intérim Emploi Serviceinterim-emploi-service.fr

A company in Rennes offering temporary work, job placements, and professional development while prioritizing employee skills, safety, diversity, and discrimination prevention

Staffing and Recruiting 🇫🇷 Saint-Grégoire 228 2005
21
Axys Consultantsaxys-consultants.com

Management consultancy providing digital transformation, data analytics, and operational excellence services across procurement, finance, marketing, and sales departments for large international corporate clients.

Business Consulting and Services 🇫🇷 Levallois Perret 227 1987
22
Cerfrance Finistèrefinistere.cerfrance.fr

Accounting and consulting firm providing services to businesses and their leaders in Finistère, specializing in advice and expertise in accounting

Accounting 🇫🇷 Quimper 216 n/a
23
Aqualehaaqualeha.com

The company offers a range of services to prevent food, safety, and environmental risks for the protection of assets and individuals

Biotechnology Research 🇫🇷 Vitré 216 1984
24
Icoopaicoopa.bzh

ICOOPA is a management and accounting association founded in 1977, serving over 5,000 members in agriculture, crafts, and trade sectors in Brittany, France

Accounting 🇫🇷 Morlaix 195 1977
25
Groupe SECOBsecob.fr

Provides accounting, payroll, and audit services supporting over 3500 companies in creation, development, and business transfer phases.

Business Consulting and Services 🇫🇷 Cesson-Sévigné 192 1963

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26
Groupe Interactioninteraction-groupe.com

This company facilitates employment access, offering temp agencies, recruitment firms, specialized services, digital solutions, and a training center for diverse job seekers.

Staffing and Recruiting 🇫🇷 Rennes 178 1991
27
Arkéa Investment Servicesarkea-is.com

Asset management company combining financial and extra-financial performance, offering diverse investment solutions for individual and institutional clients.

Financial Services 🇫🇷 171 1980
28
Lavancelavance.com

Provider of vehicle washing equipment and services including high-pressure centers, tunnels, water recycling, financing, maintenance, and station operation support.

Automation Machinery Manufacturing 🇫🇷 Le Rheu 168 1979
29
METIcgi.com

Specializing in business process management solutions for retail, this software development company provides services and support to major clients worldwide

IT Services and IT Consulting 🇫🇷 Larmor-Plage 166 1982
30
isatechisatech.fr

International IT solutions provider specializing in ERP & CRM solutions, Microsoft Dynamics 365 expertise, BI, Azure, and professional services for various industry sectors worldwide

IT Services and IT Consulting 🇫🇷 Vannes 158 1983
31
Groupe Astengroupe-asten.fr

A company specializing in digital transformation, offering hosting, cybersecurity, custom software development, retail solutions, and consulting with a focus on Brittany's growth

IT Services and IT Consulting 🇫🇷 Gouesnou 150 1995
32
TALENDItalendi.com

A social enterprise offering industrial and digital services, employing over 550 people, including 420 with disabilities, with expertise in various fields like assembly and logistics

Motor Vehicle Parts Manufacturing 🇫🇷 Rennes 137 1975
33
OJC Conseilojc-consulting.com

This consulting firm offers IT services for purchase, sales, and treasury management Specializing in IT transformation projects with expertise in IVALUA solutions

Software Development 🇫🇷 Vannes 135 2007
34
E&C Expertise Comptableby-ec.fr

Independent accounting and collaborative services firm providing expertise in various areas such as accounting, business advisory, legal counseling, payroll, and administration support

Accounting 🇫🇷 Brest 127 1979
35
In Extenso Bretagneinextenso.fr

A major player in accounting and consulting for small and medium-sized businesses, offering support in all areas of business management

Accounting 🇫🇷 Brest 125 1991
36
Adventieladventiel.fr

Adventiel is a specialized consultancy firm assisting agricultural and food industries in transitioning to sustainable models through customized digital solutions

Software Development 🇫🇷 Pacé 107 n/a
37
Pros-Consultepros-consulte.com

Supports organizations in preventing psychosocial risks, enhancing mental health, and fostering well-being at work, improving collective performance and employee engagement.

Human Resources Services 🇫🇷 Lorient 101 2009
38
Tourny Meyertournymeyer.fr

Offers business real estate consulting, sales, and leasing services for offices, warehouses, retail, hotels, and urban developments across multiple French cities.

Real Estate 🇫🇷 Rennes 101 1990
39
TALENZ TOADENNtalenz.fr

Multidisciplinary consulting firm supporting entrepreneurs and business leaders with strategy, finance, compliance, audit, legal, HR, and technology solutions.

Business Consulting and Services 🇫🇷 Rennes 92 n/a
40
ADENTadentingenierie.com

Designing sustainable and adaptable agri-food factories that are both thoughtful and harmonious in their construction and operation

Construction 🇫🇷 Rennes 92 2006
41
APAVE REGION BRETAGNE-MAINEapave.com

Apave provides comprehensive risk management services to companies and communities worldwide, aiming to increase safety, protect the environment, and optimize organizational performance

Environmental Services 🇫🇷 Le Rheu 89 1867
42
CYIMcyim.com

A company specializing in IT and audiovisual services for medical societies, offering digital solutions for medical congresses and associations

IT Services and IT Consulting 🇫🇷 Rennes 88 2001
43
Happy to meet youhappytomeetyou.fr

Provides human resources and communication expertise to companies, focusing on executive recruitment and HR consulting, including organizational transformation, development, and skill assessments.

Human Resources Services 🇫🇷 Rennes 71 2016
44
Excelis Conseilexcelis-conseil.fr

Accounting and audit firm with 75 professionals and 6 partners in Rennes and Vannes Serving 1,500+ clients in the Grand Ouest region

Accounting 🇫🇷 Pacé 70 2003
45
IFOPSEifopse.com

Specializing in safety training and consulting for nearly 40 years, the company helps manage personnel safety in areas such as fire, chemical, and crisis management

Professional Training and Coaching 🇫🇷 Nivillac 70 1983
46
L'Optimiste le Groupeloptimiste.fr

Collective of experts providing strategy, accounting, HR, legal, financing, and CSR support to over 1,500 SMEs in France.

Accounting 🇫🇷 Rennes 68 2016
47
COMPTAGESMAcomptagesma.com

Comptagesma guides entrepreneurs from company creation to accounting, tax optimization, and strategic advice, with a focus on proximity, technology, and social responsibility

Accounting 🇫🇷 Saint-Malo 67 1979
48
SAPIENCE AUDIT Cabinet de commissariat aux comptesaac-ec.com

An independent accounting and consulting firm providing tailored support and strategic advice to business owners in Pays de Lorient

Accounting 🇫🇷 Ploemeur 63 1989
49
Télémaquetelemaque-penelope.nous-recrutons.fr

A leading call center company in France offering services such as lead generation, telemarketing, appointment setting, sales, and customer support with extensive training and growth opportunities

Telephone Call Centers 🇫🇷 Caudan 60 n/a
50
Cabinet BOURGOIS - Groupe MERLINcabinet-merlin.fr

A recognized player in environmental consulting and engineering for over 80 years, based in Betton, France, as a subsidiary of Groupe MERLIN

Environmental Services 🇫🇷 Betton 53 1938

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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 11, 2026.

More company lists in Brittany

The same list elsewhere in France