Solvay SA

Major Shareholding Notification • Aug 26, 2025

Final

	Name SOLVAY
Identification number 0403-091-220

0

³ +

0

² +

0

^A +

Part II

7) Date on which the threshold is crossed

18/08/2025 (DD/MM/YYYY)

3

Name Address (for legal entities)

Transparency notification Form TR-1 BE PART I

Name	Address (for legal entities)
Morgan Stanley	c/o The Corporation Trust Company (DE), Corporation Trust Center, 1209 Orange Street, Wilmington, Delaware 19801, USA	+

Please continue entering the information in part II concerning the persons referred to in Sections 5 and 6

1) Status of the notification

2) Issuer

3) Reason for the notification

5) Persons subject to the notification requirement

A) Voting rights	Previous notification	After the transaction
	# of voting rights	# of voting rights				% of voting rights
Holders of voting rights		Linked to securities	Not linked to the securities	Linked to securities	Not linked to the securities	S
Morgan Stanley		0	0	0.00%	0.00%	1
Morgan Stanley & Co. LLC		20	0	0.00%	0.00%	1
Morgan Stanley & Co. International plc		10,312	0	0.01%	0.00%	1
Subtotal		10,332		0.01%		S
	TOTAL	10,332	0	0.01%	0.00%

4) Notification by

6) Persons that dispose of voting rights (only to be filled in if art. 7 of the Law applies)

A parent undertaking or a controlling person

Acquisition or disposal of financial instruments that are treated as voting securities

10) Notified details

8) Threshold that is crossed (in %)

If the holding has fallen below the lowest threshold, you have the option of not entering any numbers in Section 10

9) Denominator

Start with "groups" of holders. Add subtotals with Σ, and then finish with the persons who are "alone".

For groups, start with the ultimate controlling natural person or legal entity. The totals, subtotals and % will be updated once you have clicked on .

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
Morgan Stanley & Co. International plc Equity Call Options			19/12/2025 At any time	14,900	0.01%	physical	-
Morgan Stanley & Co. International plc Equity Call Options			19/06/2026 At any time	201,200	0.19%	physical	-
Morgan Stanley & Co. International plc Equity Call Options			18/12/2026 At any time	283,100	0.27%	physical	-
Morgan Stanley & Co. International plc Equity Put Options			19/09/2025 At any time	208,800	0.20%	physical	-
Morgan Stanley & Co. International plc Equity Put Options			19/12/2025 At any time	64,900	0.06%	physical	-
Morgan Stanley & Co. International plc Equity Put Options			19/06/2026 At any time	733,400	0.69%	physical	-
Morgan Stanley & Co. International plc Equity Put Options			18/12/2026 At any time	676,800	0.64%	physical	-
Morgan Stanley & Co. International plc Equity Swap			27/11/2025 At any time	120,848	0.11%	cash	-
Morgan Stanley & Co. LLC	Right of recall over securities lending agreements	At any time	At any time	451,053	0.43%	physical	-
	Morgan Stanley & Co. International plc Right of recall over securities lending agreements	At any time	At any time	111,501	0.11%	physical	-
Prime Dealer Services Corp.	Right of recall over securities lending agreements	At any time	At any time	462,381	0.44%	physical	-
Morgan Stanley & Co. International plc Retail Structured Product - Note			02/07/2035 At any time	5,345	0.01%	cash	-
Morgan Stanley & Co. International plc Retail Structured Product - Note			16/07/2035 At any time	14,392	0.01%	cash	-
Morgan Stanley & Co. International plc Retail Structured Product - Note			01/10/2035 At any time	2,358	0.00%	cash	+
	TOTAL			3,350,978	3.16%

TOTAL (A & B)			# of voting rights % of voting rights
	CALCULATE	3,361,310	3.17%

11) Full chain of controlled undertakings through which the holding is effectively held, if applicable

Morgan Stanley's total holding in SOLVAY remains above the 3% threshold previously disclosed however, this notification is being made on the basis that Morgan Stanley & Co. International plc, a wholly owned subsidiary of Morgan Stanley, has crossed a relevant threshold in its own right.

12) In case of proxy voting for only one GM

The totals will be updated once you have clicked on

Please refer to Chain of Controlled Undertakings

13) Additional information

	Done at Glasgow
On		22/08/2025 (DD/MM/YYYY)
	Name & capacity Nga Macrow, Regulatory Operations		Signature

For security reasons, the unsigned form in xlsx format should be transmitted to trp.fin@fsma.be. You can do this manually OR if you have MS Outlook at your disposal via the "Save & Send" button.

In addition, a signed copy in PDF format should also be transmitted.

Chain of controlled undertakings

Chain of controlled undertakings for Morgan Stanley & Co. International plc

• Morgan Stanley & Co. International plc, 25 Cabot Square, Canary Wharf, London, E14 4QA, UNITED

KINGDOM. is a direct holder and is a subsidiary of Morgan Stanley Investments (UK)

• Morgan Stanley Investments (UK), 20 Bank Street, Canary Wharf, London, E14 4AD, UNITED KINGDOM. is an indirect holder and is a subsidiary of Morgan Stanley International Limited

• Morgan Stanley International Limited, 25 Cabot Square, Canary Wharf, London, E14 4QA, UNITED KINGDOM. is an indirect holder and is a subsidiary of Morgan Stanley International Holdings Inc.

• Morgan Stanley International Holdings Inc., c/o The Corporation Trust Company (DE), Corporation Trust Center, 1209 Orange Street, Wilmington, Delaware, 19801, USA. is an indirect holder and is a subsidiary of the beneficial owner, Morgan Stanley

Chain of controlled undertakings for Morgan Stanley & Co. LLC

• Morgan Stanley & Co. LLC, c/o The Corporation Trust Company (DE), Corporation Trust Center, 1209 Orange Street, Wilmington, Delaware, 19801, USA. is a direct holder and is a subsidiary of Morgan Stanley Capital Management, LLC.

• Morgan Stanley Capital Management, LLC, c/o The Corporation Trust Company (DE), Corporation Trust Center, 1209 Orange Street, Wilmington, Delaware, 19801, USA. is an indirect holder and is a subsidiary of the beneficial owner, Morgan Stanley

Chain of controlled undertakings for Prime Dealer Services Corp.

• Prime Dealer Services Corp., c/o The Corporation Trust Company (DE), Corporation Trust Center, 1209 Orange Street, Wilmington, Delaware, 19801, USA is a direct holder and is a subsidiary of Morgan Stanley & Co. LLC • Morgan Stanley & Co. LLC, c/o The Corporation Trust Company (DE), Corporation Trust Center, 1209 Orange Street, Wilmington, Delaware, 19801, USA. is a direct holder and is a subsidiary of Morgan Stanley Capital Management, LLC.

• Morgan Stanley Capital Management, LLC, c/o The Corporation Trust Company (DE), Corporation Trust Center, 1209 Orange Street, Wilmington, Delaware, 19801, USA. is an indirect holder and is a subsidiary of the beneficial owner, Morgan Stanley

Morgan Stanley is not a controlled entity.