Groupe Bruxelles Lambert SA

Transaction in Own Shares • Dec 1, 2025

Delivering meaningful growth

Transactions on GBL Shares

Disclosure of transaction on GBL shares from November 24, 2025, until November 28, 2025 (included) Implementation of the authorization of the Extraordinary General Shareholders' Meeting of May 2, 2025

Purchases

GBL, directly and through its subsidiaries, acquired during the period from November 24, 2025 until November 28, 2025 included, as part of:

• The share buyback program: 0 GBL share
• The share buyback program by an independent financial institution on the basis of a discretionary mandate (until March 13, 2026) in the central order book of a regulated market or MTF: 67,890 GBL shares

Trade date	Number of shares	Average price (EUR)	Lowest price (EUR)	Highest price (EUR)	Amount (EUR)	Market (MIC Code)
11/24/2025	1,647	73.17	72.80	73.35	120,511	AQEU
11/24/2025	11,580	73.24	72.80	73.45	848,083	CEUX
11/24/2025	2,290	73.17	72.80	73.40	167,557	TQEX
11/24/2025	4,890	73.24	72.90	73.45	358,162	XBRU
11/25/2025	1,466	73.42	73.15	73.60	107,631	AQEU
11/25/2025	3,465	73.47	73.15	73.75	254,565	CEUX
11/25/2025	2,124	73.45	73.15	73.75	156,013	TQEX
11/25/2025	2,357	73.56	73.10	73.90	173,369	XBRU
11/26/2025	1,269	73.63	73.40	73.75	93,441	AQEU
11/26/2025	6,182	73.69	73.45	73.85	455,531	CEUX
11/26/2025	2,000	73.64	73.40	73.75	147,289	TQEX
11/26/2025	2,717	73.66	73.50	73.85	200,139	XBRU
11/27/2025	800	73.90	73.75	74.00	59,122	AQEU
11/27/2025	3,626	73.93	73.80	74.00	268,052	CEUX
11/27/2025	1,400	73.90	73.75	73.95	103,454	TQEX
11/27/2025	1,489	73.92	73.75	74.00	110,068	XBRU
11/28/2025	700	74.16	73.85	74.55	51,915	AQEU
11/28/2025	2,941	74.40	73.85	74.65	218,819	CEUX
11/28/2025	1,200	74.18	73.80	74.55	89,018	TQEX
11/28/2025	13,747	74.53	73.90	74.65	1,024,508	XBRU
Total	67,890	73.76			5,007,249

• The liquidity agreement: 0 GBL share

Sales

GBL, directly and through its subsidiaries, sold during the period from November 24, 2025 until November 28, 2025 included, as part of:

• The liquidity agreement: 0 GBL share

As of November 28, 2025, GBL holds directly and through its subsidiaries 12,031,582 GBL shares representing 9.0% of the issued capital and holds no shares under the liquidity agreement. On that date, 20.5% of the eighth share buyback program is executed1.

Following GBL's decision to use the safe harbour2 regime for the on-the-market share buybacks in the context of a EUR 598.9 million envelope, the liquidity contract with an independent financial institution has been suspended for an indefinite period.

For more information, please contact:

Tel: +32 2 289 17 72 Tel: +32 2 289 17 64

Xavier Likin Alison Donohoe

Chief Financial Officer Head of Investor Relations xlikin@gbl.com adonohoe@gbl.com

About Groupe Bruxelles Lambert

Groupe Bruxelles Lambert ("GBL") is an established investment holding company, with seventy years of stock exchange listing and a net asset value of €14.0bn at the end of September 2025. As a leading and active investor in Europe, GBL focuses on long-term value creation with the support of a stable family shareholder base.

GBL is focused on delivering meaningful growth by providing attractive returns to its shareholders through a combination of growth in its net asset value per share, a sustainable dividend and share buybacks.

GBL is listed on Euronext Brussels (Ticker: GBLB BB; ISIN code: BE0003797140) and is included in the BEL20 index.

¹ cf. http://www.gbl.com/en/transactions-gbl-shares

² Provided for in Regulation (EU) No. 596/2014 of 16 April 2014 on market abuse and Delegated Regulation (EU) No. 2016/1052 of 8 March 2016 with regard to regulatory technical standards for the terms of buyback programs and stabilization measures