Overview

Compagnie des Signaux (CSEE) is a French rail-signalling company founded in 1902 and headquartered in Les Ulis, Île-de-France, France. It is part of the MERMEC Group since 2024 and employs an estimated 200 to 500 people. CSEE supplies ERTMS systems and high-speed rail signalling for passenger and freight networks, serving the rail, transport, and electronics sectors. In 2025 it and its partners Eiffage and SYSTRA commissioned the first ARGOS digital interlocking at Réding-Saverne on the French national rail network.

At a glance

What Compagnie des Signaux - Csee makes

CSEE holds ISO 9001, ISO 14001, and ISO 45001 certifications and develops ERTMS systems, interlocking systems, and digital signalling equipment.

Products and capabilities described on the company's own site include LED, Assembly, Coating, Bearing, Emissions (source: csignaux.com).

Certifications

Compagnie des Signaux - Csee is associated with the following certifications in public sources. Confirm the certified scope for the specific plant producing your part:

• ISO 14001 — csignaux.com

• ISO 45001 — csignaux.com

• ISO 9001 — csignaux.com

Latest developments

• 2026-09-22 — All news in railway signaling (csignaux.com)

• 2026-05-03 — Modernisation of RER D: Successful Commissioning of the New Interlocking Systems at Gare de Lyon Underground (csignaux.com)

• 2026-01-15 — Eurotunnel launches with Compagnie des Signaux the first phase of project to modernise rail signalling in the Channel Tunnel - Newsroom Getlink (getlinkgroup.com)

• 2025-11-23 — French National Rail Network modernization: Compagnie des Signaux and its partners Eiffage and SYSTRA successfully commission the first ARGOS digital interlocking at Reding-Saverne - Compagnie des Signaux (csignaux.com)

• 2025-10-15 — Franco-Portuguese Cooperation for High-Speed Railway Innovation - Compagnie des Signaux (csignaux.com)

• 2025-07-22 — CSEE Wins Major Contract with RATP for Maintenance of Paris Tramway Signalling Systems - Compagnie des Signaux (csignaux.com)

Company details

CSEE is a privately held subsidiary of the MERMEC Group and is involved in the LGV Kénitra–Marrakech high-speed rail project in Morocco. Compagnie des Signaux - Csee was founded in 1902, has an estimated 200-500 employees, and is headquartered in Les Ulis, Ile-de-France. On the LightSource stability read it is rated "Established & active": 124 years in operation (founded 1902). Holds ISO 14001, ISO 45001, ISO 9001 certification(s) per public sources.

Frequently asked questions

What does Compagnie des Signaux - Csee make?

Compagnie des Signaux (CSEE) is a French rail-signalling company founded in 1902 and headquartered in Les Ulis, Île-de-France, France. It is part of the MERMEC Group since 2024 and employs an estimated 200 to 500 people. CSEE supplies ERTMS systems and high-speed rail signalling for passenger and freight networks, serving the rail, transport, and electronics sectors. In 2025 it and its partners Eiffage and SYSTRA commissioned the first ARGOS digital interlocking at Réding-Saverne on the French national rail network.

Where is Compagnie des Signaux - Csee headquartered?

Compagnie des Signaux - Csee is headquartered in Les Ulis, Ile-de-France (4 Avenue du Canada, Les Ulis, Ile-de-France, 91940).

When was Compagnie des Signaux - Csee founded?

Compagnie des Signaux - Csee was founded in 1902.

How big is Compagnie des Signaux - Csee?

Compagnie des Signaux - Csee has an estimated 200-500 employees, with revenue in the $100-250M range (estimated).

What certifications does Compagnie des Signaux - Csee hold?

Compagnie des Signaux - Csee lists ISO 14001 · ISO 45001 · ISO 9001 on its website. Confirm the certified scope for the specific plant producing your part.

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Last verified Nov 2026. Is this your company? Request a correction.