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The 30 largest IT services companies in the Loire-Atlantique department

Tamtam tracks 130 IT services companies headquartered in the Loire-Atlantique department. This list ranks the 30 largest by number of employees on LinkedIn, led by Experis France, Catamania and U IRIS devient U TECH. Their median headcount is 156. Half of them were founded in 2000 or later. The most common headquarters are Saint-Herblain (10), Nantes (9) and La Chapelle-sur-Erdre (4).

馃嚝馃嚪 Loire-Atlantique30 companiesUpdated Nov 12, 2026

These large IT services companies in Loire-Atlantique provide a range of digital transformation, consulting, and software development services. Companies like Experis France support DSI with innovative digital transformation projects, while Catamania offers digital transformation services, consulting, and software publishing. Groupe Sigma aims to enhance performance through digital impact, and ASI庐 focuses on a responsible digital world. U IRIS devient U TECH manages the IT system for Groupement U, and Conserto provides IT consulting across cloud, digital, and embedded domains.

The companies listed here are primarily established mid-sized to large firms, with a concentration of headquarters in Saint-Herblain. Many were founded in the late 1990s and early 2000s, indicating a mature and well-developed IT sector in the region, focusing on diverse technical expertise and comprehensive digital solutions for various sectors.

#CompanyIndustryHeadquarters EmployeesFounded
1
Experis Franceexperisfrance.fr

Supports DSI with innovative digital transformation projects, providing IT services and talent solutions to enhance organizational performance, addressing specific needs.

IT Services and IT Consulting 馃嚝馃嚪 Nantes 2,207 n/a
2
Catamaniacatamania.com

Provides digital transformation services, consulting, software publishing, and information system architecture for banking, insurance, and retail sectors across international agencies using diverse technical expertise.

IT Services and IT Consulting 馃嚝馃嚪 Saint-Herblain 797 1999
3
U IRIS devient U TECHu-emploi.com

Management and innovation of the entire Groupement U IT system, supporting retail, supply chain, and digital transformation projects.

Software Development 馃嚝馃嚪 Carquefou 637 2011
4
Groupe Sigmasigma.fr

The company aims to enhance performance through digital impact, innovate eco-friendly solutions, and build digital ecosystems with expert dialogue

IT Services and IT Consulting 馃嚝馃嚪 La Chapelle-sur-Erdre 607 1972
5
ASI 庐asi.fr

Working towards a responsible digital world dedicated to serving humanity

IT Services and IT Consulting 馃嚝馃嚪 Saint-Herblain 590 1993
6
Consertoconserto.pro

Offers IT consulting and expertise services across cloud, digital, and embedded domains through consulting, delivery centers, and labs models.

IT Services and IT Consulting 馃嚝馃嚪 Saint-Herblain 555 2013
7
4CAD Group4cadgroup.com

The company offers PLM, ERP, and IoT tools to help organizations optimize their information systems for increased industrial efficiency

Software Development 馃嚝馃嚪 Bouguenais 463 2004
8
AISgroupeais.fr

AIS is a human-centric company providing expertise to clients since 1985, focusing on professional growth and fulfillment of its employees

IT Services and IT Consulting 馃嚝馃嚪 Saint-Herblain 289 1985
9
Younupyounup.fr

This company offers IT services, supporting clients throughout the software lifecycle from requirements to production, focusing on web, DevOps, data, AI, agility, mobile, and cloud.

IT Services and IT Consulting 馃嚝馃嚪 Nantes 224 2019
10
GROUPE SYDsyd.fr

Specializing in digital transformation, the company offers consultancy, project management, infrastructure services, Microsoft solutions integration, application development, and Microsoft expertise, emphasizing customer satisfaction and trust

IT Services and IT Consulting 馃嚝馃嚪 Saint-Herblain 190 1999
11
Dynamipsdynamips.com

A pioneer in professional IT services, providing support to SMEs and Local Authorities across France Specializing in optimizing systems, data security, cloud solutions, and personalized IT services

Computer Networking Products 馃嚝馃嚪 Saint-Herblain 179 1992
12
ORINOXorinox.com

Software consulting and plant design firm specializing in digitalization using AVEVA software suite for engineering, asset data visualization, resources management, simulation, and training

Business Consulting and Services 馃嚝馃嚪 Chateaubriant 166 2008
13
VFLIT - Vous faciliter l'ITvousfaciliter-it.fr

Providing integrated cybersecurity, cloud, telecom, management applications, and safety services to enhance organizational IT and communication system performance.

Retail Office Equipment 馃嚝馃嚪 Saint-S茅bastien-sur-Loire 164 2000
14
MOCAasi.fr

MOCA by ASI specializes in offering technical expertise and support for Microsoft solutions to users within the Microsoft ecosystem

IT Services and IT Consulting 馃嚝馃嚪 Saint-Herblain 159 2022
15
Valeuriadvaleuriad.fr

Experts in transforming complex information systems, providing technical excellence in AI, data engineering, cloud, and infrastructure for large organizations.

IT Services and IT Consulting 馃嚝馃嚪 Nantes 156 2015

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16
Capaciticapaciti.com

A regional leader in cybersecurity, providing specialized services in consulting, engineering, and system infrastructure support with offices in France and international project capabilities

IT Services and IT Consulting 馃嚝馃嚪 Carquefou 150 1999
17
KOSMOSkosmos-education.com

Specializing in digital education solutions, this company implements web portals, e-portfolios, mobile apps, and other digital tools for schools

IT Services and IT Consulting 馃嚝馃嚪 Nantes 141 1998
18
kanomakanoma.fr

Experts guide clients digital transformation, from design to production, focusing on agile projects, development, product design, and organizational change.

IT Services and IT Consulting 馃嚝馃嚪 Nantes 128 2018
19
Timcodtimcod.fr

Provider of IT solutions for mobile workers in logistics and transportation, specializing in barcode scanners, Wi-Fi, voice recognition, and RFID technology

IT Services and IT Consulting 馃嚝馃嚪 Carquefou 118 2002
20
proLogistik France (DSIA)logistar-dsia.com

French subsidiary of a pan-European group, publishing, integrating, and hosting supply chain solutions, including WMS, OMS, LMS, TMS, ensuring optimal security and accessibility.

Software Development 馃嚝馃嚪 Nantes 114 1985
21
Mismo Informatiquemismo.fr

A comprehensive IT solutions provider offering infrastructure, hardware, software, and services to streamline operations for 3,000 businesses, with certifications and partnerships with industry leaders

IT Services and IT Consulting 馃嚝馃嚪 La Chapelle-sur-Erdre 113 1992
22
A5sysa5sys.com

Founded in 2001, the company specializes in IT services focusing on business intelligence, databases, and application development

IT Services and IT Consulting 馃嚝馃嚪 Saint-Herblain 92 2001
23
Le Pharelephare.com

Digital product factory for SMEs, ETIs, and industries Provides digital transformation consulting and custom platforms to accelerate B2B and B2B2C businesses

Technology, Information and Internet 馃嚝馃嚪 Nantes 87 2000
24
Iliane Informatiqueiliane.fr

Providing comprehensive IT solutions for businesses of all sizes to effectively manage their information systems

IT Services and IT Consulting 馃嚝馃嚪 Saint-Herblain 83 1982
25
Mercuriamercuria.fr

Advises and supports businesses with SaaS, Cloud, or hosted solutions for accounting, financial, payroll, and HR management software, working with reliable publishers.

Software Development 馃嚝馃嚪 La Chapelle-sur-Erdre 82 1999
26
mobiappsFrmobiapps.fr

mobiApps specializes in creating multiplatform mobile apps using emerging hybrid technologies like HTML/CSS and JavaScript, along with digital strategy services

Software Development 馃嚝馃嚪 Orvault 74 2014
27
Voxalyvoxaly.com

Specialized in electronic voting systems, organizing elections for labor unions, supervisory boards, shareholder meetings for top French companies Customized solutions since 2006

IT Services and IT Consulting 馃嚝馃嚪 Saint-Herblain 73 2006
28
ELEPHANT Technologieselephant-technologies.fr

Offers expert human-centered tech consultancy, ensuring perfect alignment between client needs and employee skills across various IT domains from idea to production.

IT Services and IT Consulting 馃嚝馃嚪 Nantes 69 2017
29
ABASEgeneration-net.org

ABASE 20 is a digital services company providing a variety of digital solutions and services to clients

IT Services and IT Consulting 馃嚝馃嚪 Nantes 67 1993
30
AT脡MISatemis.eu

Providing secure and responsible IT infrastructure design, deployment, and management services tailored to specific organizational needs with local support.

IT Services and IT Consulting 馃嚝馃嚪 La Chapelle-sur-Erdre 61 1997

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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 12, 2026.

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