Solvay SA — Major Shareholding Notification 2026

May 12, 2026

FSMA

FINANCIAL SERVICES AND

MARKETS AUTHORITY

Transparency notification

Form TR-1 BE

PART I

1) Status of the notification

Final

2) Issuer

Name
SOLVAY
Identification number
0403-091-220

3) Reason for the notification

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

4) Notification by

A parent undertaking or a controlling person

5) Persons subject to the notification requirement

Name	Address (for legal entities)
Citigroup Inc.	1209 North Orange Street in Wilmington, Delaware 19801, USA

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

Name	Address (for legal entities)

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

Part II

7) Date on which the threshold is crossed

07/05/2026 (DD/MM/YYYY)

8) Threshold that is crossed (in %)

3

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

9) Denominator

105,876,416

↑ Please enter the denominator before filling in the data

10) Notified details

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
Citigroup Inc.		0		0.00%
Citigroup Global Markets Limited		682,267		0.64%
Citigroup Global Markets Europe AG		12,846		0.01%
Subtotal		695,113		0.66%
TOTAL		695,113		0.66%	0.00%

↑ Start with "groups" of holders. Add subtotals with $\sum_{i}$ 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 .

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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
Citigroup Global Markets Limited	SWAPS		03.08.2026-04.02.202	595,316	0.56%	cash
Citigroup Global Markets Funding Luxembourg S.C.A.	Option		18.02.2027	177,430	0.17%	physical
Citigroup Global Markets Limited	Option		18.12.2026	34,071	0.03%	physical
Citigroup Global Markets Limited	Option		22.12.2026	3,604	0.00%	cash
Citigroup Global Markets Limited	Long Call		18.09.2026	150,000	0.14%	physical
Citigroup Global Markets Limited	Short Put		18.12.2026-17.12.202	1,550,000	1.46%	physical
TOTAL				2,510,421	2.37%

1 The totals will be updated once you have clicked on

TOTAL (A & B)

	# of voting rights	% of voting rights
CALCULATE	3,205,534	3.03%

11) Full chain of controlled undertakings through which the holding is effectively held. # applicable

12) In case of proxy voting for only one GM

Holder

will cease to hold / will hold again

0

voting rights as of

(DO/MM/YYYY)

13) Additional information

Crossing above 3% which is the lowest threshold per the issuer's articles of association

Done at Belfast

On 12/05/2026 (DO/MM/YYYY)

Name & capacity Cathal McKenna, Regulatory Operations

Signature Cathal McKenna

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

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