Groupe Bruxelles Lambert SA

Transaction in Own Shares • Nov 3, 2025

Delivering meaningful growth

Transactions on GBL Shares

Disclosure of transaction on GBL shares from October 27, 2025, until October 31, 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 October 27, 2025 until October 31, 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: 58,483 GBL shares

Trade date	Number of shares	Average price (EUR)	Lowest price (EUR)	Highest price (EUR)	Amount (EUR)	Market (MIC Code)
10/27/2025	6,395	78.46	78.25	78.60	501,738	CEUX
10/27/2025	1,355	78.39	78.30	78.50	106,222	TQEX
10/27/2025	8,548	78.44	78.15	78.65	670,486	XBRU
10/28/2025	2,632	78.32	78.15	78.50	206,141	CEUX
10/28/2025	1,204	78.28	78.20	78.40	94,255	TQEX
10/28/2025	11,234	78.25	78.15	78.50	879,089	XBRU
10/29/2025	2,331	78.41	78.15	78.60	182,772	CEUX
10/29/2025	1,188	78.43	78.10	78.50	93,173	TQEX
10/29/2025	6,919	78.40	78.10	78.65	542,446	XBRU
10/30/2025	1,909	77.90	77.60	78.05	148,703	CEUX
10/30/2025	689	77.70	77.60	77.75	53,534	TQEX
10/30/2025	2,943	77.84	77.60	78.05	229,080	XBRU
10/31/2025	1,494	76.49	76.00	77.40	114,276	CEUX
10/31/2025	862	76.80	76.45	77.00	66,203	TQEX
10/31/2025	8,780	76.48	76.05	77.70	671,459	XBRU
Total	58,483	77.96			4,559,578

• The liquidity agreement: 0 GBL share

Sales

GBL, directly and through its subsidiaries, sold during the period from October 27, 2025 until October 31, 2025 included, as part of:

• The liquidity agreement: 0 GBL share

As of October 31, 2025, GBL holds directly and through its subsidiaries 11,631,622 GBL shares representing 8.7% of the issued capital and holds no shares under the liquidity agreement. On that date, 14.6% 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 €14.4bn 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 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