Syensqo SA/NV

Major Shareholding Notification • Jul 9, 2025

Participation notification by BlackRock Inc.

Brussels, Belgium – July 09, 2025 - 8:30 CEST

According to Belgian transparency legislation (Law of May 2, 2007), BlackRock Inc. (12 Throgmorton Avenue, London EC2N 2DL, UK) recently sent Syensqo the following transparency notifications indicating that it crossed the threshold of 3%. Here is the summary of the moves:

Date on which the	Voting rights after the	Equivalent financial instruments	Total
threshold was crossed	transaction	after the transaction
July 01, 2025	3.10%	0.64%	3.74%

The latest notification, dated July 03, 2025 and received on July 04, 2025, contains the following information:

• Reason for the notification:
  • Acquisition or disposal of the control of an undertaking that holds a participating interest in an issuer
  • As a result of the acquisition of HPS Investment Partners, there has been a change to BlackRock's group structure. Upon the close of the transaction, BlackRock, Inc. contributed all of its equity interests in BlackRock Finance, Inc. and Global Infrastructure Management, LLC to BlackRock Saturn Subco, LLC, a wholly owned subsidiary of the Company.
• Notified by: BlackRock Inc : A parent undertaking or a controlling person
• Date on which the threshold is crossed: July 0 1, 2025
• Threshold of direct voting rights crossed: 3% upwards
• Denominator: 105,876,417
• Additional information: The disclosure obligation arose due to voting rights attached to shares for BlackRock, Inc. going above 3%.
• Persons subject to the notification requirement:

Name	Address (for legal entities)
BlackRock, Inc.	50 Hudson Yards, New York, NY, 10001, U.S.A.
BlackRock (Singapore) Limited	20 Anson Road #18-01, Singapore, 79912, Singapore
BlackRock Advisors (UK) Limited	12 Throgmorton Avenue, London, EC2N 2DL, U.K.
BlackRock Advisors, LLC	50 Hudson Yards, New York, NY, 10001, U.S.A.
BlackRock Asset Management Canada Limited	161 Bay Street, Suite 2500, Toronto, Ontario, M5J 2S1, Canada
BlackRock Asset Management Deutschland AG	Lenbachplatz 1 1st Floor, Munich, 80333-MN3, Germany
BlackRock Asset Management North Asia Limited	15/F, 16/F, 17/F Citibank Tower & 17/F ICBC Tower, 3 Garden Road, Central, Hong Kong
BlackRock Financial Management, Inc.	50 Hudson Yards, New York, NY, 10001, U.S.A.
BlackRock Fund Advisors	400 Howard Street, San Francisco, CA, 94105, U.S.A.
BlackRock Institutional Trust Company, National Association	400 Howard Street, San Francisco, CA, 94105, U.S.A.
BlackRock Investment Management (Australia) Limited	Level 37 Chifley Tower, 2 Chifley Square, Sydney NSW 2000, Australia
BlackRock Investment Management (UK) Limited	12 Throgmorton Avenue, London, EC2N 2DL, U.K.
BlackRock Investment Management, LLC	1 University Square Drive, Princeton, NJ, 8540, U.S.A.
BlackRock Japan Co., Ltd.	1-8-3 Marunouchi Chiyoda-ku, Trust Tower Main, Tokyo, 100-8217, Japan
Aperio Group, LLC	3 Harbor Dr Suite 204, Sausalito, CA 94965, U.S.A.

Notified details

A) Voting rights	Previous notification	After the transaction
	# of voting rights		# of voting rights	% of voting rights
Holders of voting rights		Not linked to the Linked to securities securities		Linked to securities	Not linked to the securities
BlackRock, Inc.	0	0		0.00%
BlackRock (Singapore) Limited	4,355	4,355		0.00%
BlackRock Advisors (UK) Limited	384,946	346,059		0.33%
BlackRock Advisors, LLC	47,772	47,772		0.05%
BlackRock Asset Management Canada Limited	58,058	58,003		0.06%
BlackRock Asset Management Deutschland AG	187,652	187,757		0.18%
BlackRock Asset Management North Asia Limited	2,356	2,356		0.00%
BlackRock Financial Management, Inc.	7,871	7,871		0.01%
BlackRock Fund Advisors	1,340,706	1,339,828		1.29%
BlackRock Institutional Trust Company, National Association	879.724	884,295		0.85%
BlackRock Investment Management (Australia) Limited	17,082	17,082		0.02%
BlackRock Investment Management (UK) Limited	96,033	111,620		0.11%
BlackRock Investment Management, LLC	102,257	102,811		0.10%
BlackRock Japan Co., Ltd.	96,887	82.764		0.08%
Aperio Group, LLC	29,718	29.718		0.03%
Subtotal	3,255,417	3,222,291		3.10%
TOTAL		3,222,291	0	3.10%	0.00%

B) Equivalent financial instruments	After the transaction
Holders of equivalent financial instruments	Type of financial instrument	Expiration date	Exercise period or date	# of voting rights that may be acquired if the instrument is exercised	% of voting rights	Settlement
BlackRock Advisors (UK) Limited	Securities Lent			494.198	0 48%	physical
BlackRock Investment Management (UK) Limited	Securities Lent			166,869	0 16%	physical
	TOTAL			661,067	0.64%

TOTAL (A & B)			# of voting rights % of voting rights
	CALCULATE I	3,883,359	3.74%

Transparency notifications and the full chain of controlled undertakings through which the holding is effectively held is available on the Investor Relations Section of Syensqo's website.

Contacts

Investors & Analysts Media investor.relations@syensqo.com media.relations@syensqo.com Sherief Bakr +44 7920 575 989 Perrine Marchal +32 478 32 62 72 Bisser Alexandrov +33 607 635 280 Laetitia Schreiber +32 487 74 38 07 Loïc Flament +32 478 69 74 20 Robbin Moore-Randolph +1 470 493 2433

About Syensqo

Syensqo is a science company developing groundbreaking solutions that enhance the way we live, work, travel and play. Inspired by the scientific councils which Ernest Solvay initiated in 1911, we bring great minds together to push the limits of science and innovation for the benefit of our customers, with a diverse, global team of more than 13,000 associates.

Our solutions contribute to safer, cleaner, and more sustainable products found in homes, food and consumer goods, planes, cars, batteries, smart devices and health care applications. Our innovation power enables us to deliver on the ambition of a circular economy and explore breakthrough technologies that advance humanity.

Useful links

• Earnings materials
• Strategy
• Share information
• Credit information
• Separation documents
• Webcasts, podcasts and presentations
• Annual Integrated Report
• Subscribe to our distribution list