PRESS RELEASE

5:50 PM, 28 May 2026

COMBINED ORDINARY AND EXTRAORDINARY GENERAL MEETING OF 18 JUNE 2026

AVAILABILITY OF THE PREPARATORY DOCUMENTS

The Combined Ordinary and Extraordinary General Meeting of ALTEN SA (the “Company”) will take place on 18 June 2026, at 10:00 a.m. in the conference room of Espace Landowski, located at 28 avenue André Morizet, in Boulogne-Billancourt (92100).

The preliminary notice of the General Meeting, including the agenda and the draft resolutions was published in the “Bulletin des Annonces Légales Obligatoires” (“BALO”) on 6^th of May 2026. Notice of meeting will be published in the BALO and in a French legal gazette on 29^th of June 2026.

The preparatory documents for the General Meeting, as listed in article R. 22-10-23 of the French Commercial Code, are posted on the Company's website: www.alten.com/investors/shareholders-area/, and are also available to the shareholders in accordance with the applicable regulatory provisions.

In this context, it is reminded that:

• any shareholder holding registered shares may, up to the fifth day, inclusive, prior to the General Meeting, request the documents listed in the articles R. 225-81 and R. 225-83 of the French commercial code from the Company, where applicable by electronic means (subject to the conditions prescribed by the regulation). For shareholders holding bearer shares, the exercise of this right is subject to the submission of a shareholding certificate delivered by their authorized financial intermediary;
• any shareholder may consult the documents referred to in Articles L. 225-115 and R. 225-83 of the French Commercial Code at the Company’s registered office.

About ALTEN SA

For all information: www.alten.com/investors

Contact for journalists: alten@hopcotch.fr

As the European leader in Engineering and Technology Consulting (ETC), ALTEN carries out design and research projects for the Technical and IT/IS Departments of major industrial, telecom and tertiary clients. The ALTEN share is listed on compartment A of the Euronext Paris market (ISIN FR0000071946) and is part of SBF 120, the IT CAC 50 index, and MIDCAP 100, and is eligible for the Deferred Settlement Service (DSS).

© ALTEN Communication Department - www.alten.fr