Groupe Bruxelles Lambert SA

Transaction in Own Shares • Aug 25, 2025

Transactions on GBL Shares

Disclosure of transaction on GBL shares from August 18, 2025, untilAugust 22, 2025 (included) Implementation of the authorization of the Extraordinary General Shareholders' Meeting of April 28, 2020

Purchases

GBL, directly and through its subsidiaries, acquired during the period from August 18, 2025 until August 22, 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 November 7, 2025) in the central order book of a regulated market or MTF: 88,153 GBL shares

	Number of	Average price	Lowest price	Highest price	Amount	Market
Trade date	shares	(EUR)	(EUR)	(EUR)	(EUR)	(MIC Code)
08/18/2025	1,445	75.00	74.90	75.15	108,380	CEUX
08/18/2025	605	75.18	74.90	75.65	45,485	TQEX
08/18/2025	15,022	75.05	74.85	75.70	1,127,467	XBRU
08/19/2025	6,112	75.85	75.45	76.10	463,574	CEUX
08/19/2025	2,790	75.83	75.40	76.05	211,571	TQEX
08/19/2025	11,493	75.90	75.30	76.10	872,335	XBRU
08/20/2025	6,541	76.01	75.90	76.15	497,202	CEUX
08/20/2025	2,492	76.06	75.95	76.15	189,540	TQEX
08/20/2025	9,458	76.03	75.85	76.15	719,096	XBRU
08/21/2025	2,337	75.98	75.65	76.20	177,562	CEUX
08/21/2025	624	75.87	75.65	76.20	47,342	TQEX
08/21/2025	5,234	75.88	75.65	76.20	397,150	XBRU
08/22/2025	6,999	76.39	75.85	76.75	534,682	CEUX
08/22/2025	2,383	76.23	75.85	76.70	181,649	TQEX
08/22/2025	14,618	76.44	75.75	76.75	1,117,385	XBRU

• The liquidity agreement: 0 GBL share

Sales

GBL, directly and through its subsidiaries, sold during the period from August 18, 2025 until August 22, 2025 included, as part of:

• The liquidity agreement: 0 GBL share

As of August 22, 2025, GBL holds directly and through its subsidiaries 10,802,304 GBL shares representing 8.1% of the issued capital and holds no shares under the liquidity agreement. On that date, 2.0% 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 xlikin@gbl.com adonohoe@gbl.com

Xavier Likin Alison Donohoe

Chief Financial Officer Head of Investor Relations

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 €14.4bn at the end of June 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 aims to grow its diversified high-quality portfolio of listed, direct private and indirect private investments.

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