Assystem

Earnings Release • Oct 28, 2025

Revenue for the 9 months ended 30 September 2025: €484.2 million (up 8.7%)

• Organic growth: 5.4%, led by International business
• Full-year 2025 targets maintained

Paris-La Défense, Tuesday 28 October 2025, 5.35 p.m. (CET) – Assystem S.A. (ISIN: FR0000074148 - ASY), an international engineering group, is today releasing its revenue figures for the nine months ended 30 September 2025 and the third quarter of 2025.

Consolidated revenue for the 9 months ended 30 September 2025

and year-on-year changes vs 2024 (unaudited)

In millions of euros	9 months	9 months	% change	% change
	2024	2025	(reported)	(organic(2))
Group(1)	445.4	484.2	+8.7%	+5.4%
France	278.9	284.8	+2.1%	+2.1%
International(1)	166.5	199.3	+19.7%	+10.9%

⁽¹⁾ Consolidation since 1 January 2025 of the UK company, Mactech Energy Group, specialised in construction capabilities for the nuclear industry.

In the third quarter of 2025, consolidated revenue kept up its solid growth trajectory, rising 9.4% to €157.7 million (from €144.1 million in Q3 2024). Organic growth was 6.8%, changes in the scope of consolidation had a positive 4.8% impact, and the currency effect was a negative 2.2%.

In the first nine months of 2025, Assystem's consolidated revenue totalled €484.2 million, compared with €445.4 million in the same period of 2024. This represents total growth of 8.7%, breaking down as 5.4% organic growth, a positive 4.1% due to changes in the scope of consolidation, and a negative 0.8% currency effect. Nuclear activities accounted for 76% of the Group's total revenue for the nine-month period.

Revenue trends by geographic segment remained in line with the first half of the year:

• In France, revenue amounted to €284.8 million (59% of the nine-month consolidated total), representing 2.1% growth which was entirely organic. A good performance from fuel cycle activities helped to offset the absence of acceleration from nuclear reactor new-builds and lower volumes of business from France's nuclear installed base.
• Revenue from International operations came to €199.3 million (41% of the nine-month consolidated total). This strong 19.7% year-on-year increase includes 10.9% organic growth (with another solid performance by the United Kingdom), a favourable 11.0% impact from changes in the scope of consolidation (with ongoing growth momentum from Mactech Energy Group, which has been consolidated since 1 January 2025), and a negative 2.1% currency effect. Assystem is continuing its international expansion drive, with the creation of subsidiaries in Kazakhstan to support the country's implementation of its civil nuclear programme, and in Canada to meet the needs of the North American market.

As previously announced, Assystem's targets for full-year 2025 are: organic consolidated revenue growth(1) of around 5% and a stable EBITA margin(2) .

⁽²⁾ On a constant scope of consolidation and currency basis.

⁽¹⁾ On a constant scope of consolidation and currency basis.

⁽²⁾ Operating profit before non-recurring items (EBITA – Earnings before Interest and Taxes – from Activity) including share of profit of equity-accounted investees (other than Expleo Group & MPH) divided by consolidated revenue.

2026 FINANCIAL CALENDAR

Tuesday 10 February: Full-year 2025 revenue release

Tuesday 10 March: Full-year 2025 results release – Results presentation on Wednesday 11 March at 8.30 a.m. (CET)

Thursday 23 April: First-quarter 2026 revenue release

Friday 22 May: Annual General Meeting

Thursday 23 July: First-half 2026 revenue release

Tuesday 15 September: First-half 2026 results release – Presentation meeting on Wednesday 16 September at 8.30

a.m. (CEST)

Tuesday 27 October: Third-quarter 2026 revenue release

ABOUT ASSYSTEM

Assystem, one of the world's leading independent nuclear engineering companies, is committed to accelerating the energy transition. With 60 years of experience in highly regulated sectors with stringent safety and security constraints, the Group provides engineering and project management services as well as digital solutions and services to optimise the performance of complex infrastructure assets throughout their life cycle.

In its 13 countries of operation, Assystem's 8,000 experts are supporting energy transition. To achieve an affordable low carbon energy supply, Assystem is committed to the development of low carbon electricity (nuclear, renewables and electricity grids) and clean hydrogen. The Group is also helping drive the use of low carbon electricity in industrial sectors such as transportation. Assystem is currently ranked in the world's top three nuclear engineering groups.

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 – Tel.: +33 (0)1 41 25 29 00 Anne-Charlotte Dagorn – VP Marketing and Communication – acdagorn@assystem.com – Tel.: +33 (0)6 83 03 70 29 Agnès Villeret – Komodo – Investor relations – agnes.villeret@agence-komodo.com – Tel.: +33 (0)6 83 28 04 15

QUARTERLY REVENUE

NOTE: As the changes referred to in this press release are calculated based on exact figures, there may be discrepancies in the totals and percentages shown in the following tables due to rounding.

In millions of euros Group(1)	Q1 2024 154.3	Q1 2025 166.3	% change (reported) +7.8%	% change (organic(2)) +3.5%
In millions of euros	Q2 2024	Q2 2025	% change (reported)	% change (organic(2))
Group(1)	147.0	160.1	+8.9%	+6.0%
France International(1)	92.0 55.0	94.7 65.5	+2.9% +19.0%	+2.9% +11.2%
In millions of euros	Q3 2024	Q3 2025	% change (reported)	% change (organic(2))
Group(1)	144.1	157.7	+9.4%	+6.8%
France International(1)	89.3 54.8	91.9 65.9	+2.8% +20.2%	+2.8% +13.2%

⁽¹⁾ Consolidation since 1 January 2025 of the UK company, Mactech Energy Group, specialised in construction capabilities for the nuclear industry.

⁽²⁾ On a constant scope of consolidation and currency basis.