PRESS RELEASE

Postponement of the publication of the 2026 half-year results

Paris La Défense, Thursday 10 September 2026, 5.45 p.m. (CEST) – Assystem S.A. announces that the release of its half-year financial results, originally scheduled for September 15, 2026, has been postponed to a later date which will be communicated to the market as soon as possible.

This postponement is solely due to a delay in the timetable required by Expleo Group to complete the limited review of its half-year financial statements.

In spring 2026, Expleo Group negotiated an Amend and Extend (A&E) of the senior credit facilities of Expleo Services SAS (including a 2.5-year extension of their maturity dates). This A&E is subject to the completion or signing of asset disposals before September 30, 2026, with a view to repaying €70 million of debt (see rating agency publications below¹).

As of the date of this press release, the A&E has not yet become effective, thereby preventing Expleo Group's auditors from completing their review procedures.

Any potential accounting impacts arising from this situation will be reflected in Assystem S.A.’s half-year financial statements when they are published (see chapter 5, note 6.4 to the consolidated financial statements included in the 2025 Universal Registration Document).

ABOUT ASSYSTEM

Assystem ranks among the world's top three independent nuclear engineering leaders. With over 60 years' experience in highly regulated sectors, the Group supports public and industrial stakeholders in the delivery of complex and strategic infrastructure projects, subject to stringent safety and security requirements.

Assystem brings together some 8,000 experts across 12 countries and operates throughout the entire project lifecycle, providing engineering, project management and digital solutions.

Assystem forms part of the Euronext Tech Leaders, CAC Small, CAC Mid & Small, CAC Industrials, CAC All-Tradable, CAC All￾Share, PEA-PME 150 and MSCI Small cap Index France indices.

To find out more, visit www.assystem.com

CONTACTS

Malène Korvin – Chief Financial Officer – mkorvin@assystem.com
Jean-Baptiste Guillerme – Director of Marketing and Communications – jbguillerme@assystem.com
Agnès Villeret – Komodo – Investor relations – agnes.villeret@agence-komodo.com – Tel.: +33 (0)6 83 28 04 15

Notes

1. Expleo Group SAS 'B-' Ratings Placed On | S&P Global Ratings / Fitch Downgrades Expleo Group to 'CCC+'/'RWN'