Syensqo SA/NV

AGM Information • Apr 4, 2025

Sir, Madam,

We have the pleasure to convene you to the Ordinary Shareholders' Meeting of Syensqo SA to be held on Tuesday 6 May 2025 at 10.30 a.m. (Belgian time) at SQUARE Brussels, Mont des Arts, 1000 Brussels, Belgium (the "Shareholders' Meeting"). The agenda of this Shareholders' Meeting is attached hereto.

The Shareholders' Meeting will be organised in a hybrid manner, both in person and virtually. Shareholders who wish to do so will be able to participate physically in the Shareholders' Meeting. Alternatively, those who wish to do so can exercise their rights either by granting a proxy form or by a vote by correspondence form or by participating and voting live in a virtual and interactive manner at the Shareholders' Meeting.

Shareholders have the choice of using the Lumi Connect platform (www.lumiconnect.com) or directly contacting Syensqo SA to complete the participation formalities (as described below). However, virtual participation in the Shareholders' Meeting always requires the use of the Lumi Connect platform. A document explaining the different steps to follow for the use of the Lumi Connect platform will be available on our website.

The resolution proposals will be submitted for electronic votes. Proxy votes and votes by correspondence will be counted in advance and systematically recorded for each point. One share is equal to one vote.

IF YOU DO NOT WISH TO PARTICIPATE IN THE SHAREHOLDERS' MEETING

No formalities are required.

IF YOU WISH TO PARTICIPATE AND ATTEND IN PERSON OR VOTE BY PROXY OR BY CORREPONDENCE AT THE SHAREHOLDERS' MEETING

1) Holders of registered shares

In order to be admitted to the Shareholders' Meeting, a double formality will apply:

On the one hand, only persons who are shareholders of Syensqo SA on Tuesday 22 April 2025 at midnight (Belgian time) (hereinafter the "record date") will have the right to participate and vote at the Shareholders' Meeting, without taking into account the number of shares held by the shareholders on the day of the Shareholders' Meeting.

On the other hand, you must:

• a) either confirm to Syensqo SA your wish to participate and vote yourself at the Shareholders' Meeting. To do so, you simply need to date, sign and send us the attached NOTICE OF PARTICIPATION so that it is in our possession at the latest on the sixth day before the date of the Shareholders' Meeting, i.e. Wednesday 30 April 2025.
• b) or, if you do not intend to vote at the Shareholders' Meeting, send Syensqo SA either a proxy form by which you appoint a proxy holder of your choice or a vote by correspondence form.

To this end, you will find enclosed a PROXY FORM and a VOTE BY CORRESPONDENCE FORM that you may send us, duly completed and signed. The proxy form or the vote by correspondence form must be in our possession by Wednesday 30 April 2025 at the latest. The proxy form or the vote by correspondence form must be sent exclusively directly to Syensqo SA (and not via the Lumi Connect platform).

If you return the proxy form or the vote by correspondence form, you will still be able to attend the Shareholders' Meeting in person, but you will not be able to vote yourself as your proxy vote or vote by correspondence will already have been taken into account.

Shareholders who choose to use the Lumi Connect platform can use the platform to register to participate and vote remotely at the Shareholders' Meeting.

2) Holders of dematerialised shares

If you intend to participate in the Shareholders' Meeting, you will have to produce a certificate issued by an authorised account holder or a clearing organisation holding your securities account, certifying the registration in the shareholder's name of the number of dematerialised shares on the record date, i.e. on Tuesday 22 April 2025 at midnight, and for which you have declared your wish to participate in the Shareholders' Meeting.

For shareholders who choose to use the Lumi Connect platform, the platform allows to directly issue this certificate which, in this case, will be directly transmitted to the company.

Only persons who are shareholders of Syensqo SA on Tuesday 22 April 2025 at midnight (Belgian time) will be entitled to participate and vote at the Shareholders' Meeting, without taking into account the number of shares held by the shareholders on the day of the Shareholders' Meeting.

For shareholders who wish to be represented at the Shareholders' Meeting, you will find enclosed a PROXY FORM which you may send to us, duly completed and signed. For shareholders who wish to vote by correspondence at the Shareholders' Meeting, you will find enclosed a VOTE BY CORRESPONDENCE FORM which you may send to us, duly completed and signed. The proxy form or the vote by correspondence form must be in our possession by Wednesday 30 April 2025 at the latest. The proxy form or the vote by correspondence form must be sent exclusively directly to Syensqo SA (and not via the Lumi Connect platform).

If you return the proxy form or the vote by correspondence form, you will still be able to attend the Shareholders' Meeting in person, but you will not be able to vote yourself, as your proxy vote or vote by correspondence will already have been taken into account.

Shareholders who choose to use the Lumi Connect platform can register to participate and vote remotely during the Shareholders' Meeting.

3) Common provisions for holders of registered and dematerialised shares

The above-mentioned documents must be sent to Syensqo SA, either by post to the address of its registered office: Syensqo SA, Shareholders' Meeting, 98 rue de la Fusée, 1130 Brussels, or by e-mail: ag@syensqo.com. Shareholders who choose to use the Lumi Connect platform can use the platform to submit the above-mentioned documents, with the exception of the proxy form or the vote by correspondence form which must always be sent directly to Syensqo SA.

The proxy form and the vote par correspondence form are available at the registered office of the company and via its website: (https://www.syensqo.com/en/investors/shareholders-meetings) and from the following financial institutions: BNP Paribas Fortis, ING.

For the proxy vote, the designated proxy holder does not necessarily have to be a shareholder of Syensqo SA. When appointing the proxy, the shareholder must be particularly attentive to situations of potential conflict of interest between himself and his proxy holder (cf. Art 7:143, §4 of the Code of Companies and Associations). This provision applies in particular to the Chairman of the Shareholders' Meeting, the members of the Board of Directors, the members of the Executive Committee and, in general, the employees of Syensqo SA, their spouses or legal cohabitants and persons related to them.

If you have completed the formalities for voting by proxy or by correspondence at the Shareholders' Meeting, you may follow a live webcast of the Shareholders' Meeting organised by the company. Shareholders are invited to consult the company's website (https://www.syensqo.com/en/investors/shareholders-meetings) to find out how to access this webcast. Shareholders who have voted by proxy or by correspondence may not vote during the webcast.

FORMALITIES TO BE COMPLETED IN ORDER TO VIRTUALLY PARTICIPATE IN AND VOTE DURING THE SHAREHOLDERS' MEETING

Shareholders can choose to participate in and vote virtually during the Shareholders' Meeting via the Lumi Connect platform. In this case, voting takes place during the Shareholders' Meeting, which shareholders attend via the Lumi Connect platform. There is no need to give a proxy form nor vote by correspondence form in this case.

1) Holders of registered shares

In order to be able to virtually participate in and vote during the Shareholders' Meeting, a double formality will apply:

On the one hand, only persons who are shareholders of Syensqo SA on Tuesday 22 April 2025 at midnight (Belgian time) (hereinafter the "record date") will be entitled to participate and vote at the Shareholders' Meeting, without taking into account the number of shares held by shareholders on the day of the Shareholders' Meeting.

On the other hand, you must confirm your intention to participate in the Shareholders' Meeting. To do so, you need to confirm your intention to participate in the Shareholders' meeting on the Lumi Connect platform no later than the sixth day prior to the date of the Shareholders' Meeting, i.e. Wednesday 30 April 2025 at the latest.

You will then receive the procedure and login details to connect to the Shareholders' Meeting. Further information on the procedure is available on the Lumi website (https://www.lumiglobal.com) and the Syensqo SA website (https://www.syensqo.com/en/investors/shareholders-meetings).

2) Holders of dematerialised shares

In order to be able to participate in and vote virtually during the Shareholders' Meeting, a double formality will apply:

On the one hand, only persons who are shareholders of Syensqo SA on Tuesday 22 April 2025 at midnight (Belgian time) (hereinafter the "record date") will be entitled to participate and vote at the Shareholders' Meeting, without taking into account the number of shares held by shareholders on the day of the Shareholders' Meeting.

On the other hand, you will have to produce a certificate issued by an authorised account holder or clearing organisation holding your securities account, certifying the registration in the shareholder's name of the number of dematerialised shares on the record date and for which you have declared your wish to participate in the Shareholders' Meeting. This must be done via the Lumi Connect platform at the latest on the sixth day before the date of the Shareholders' Meeting, i.e. Wednesday 30 April 2025 at the latest. The Lumi Connect platform allows you to issue the certificate directly and to confirm your wish to participate in the Shareholders' Meeting. The certificate will be sent directly to the company.

You will then receive the procedure and login details to connect to the Shareholders' Meeting. More information on the procedure is available on the Lumi website (https://www.lumiglobal.com) and the Syensqo SA website (https://www.syensqo.com/en/investors/shareholders-meetings).

3) Common provisions for holders of registered and dematerialised shares

The Lumi Connect platform enables shareholders to (i) be directly, simultaneously and continuously informed of the discussions at the Shareholders' Meeting, (ii) exercise their voting rights on all items on which the Shareholders' Meeting is called upon to vote and (iii) participate in the deliberations and exercise their right to ask questions.

In accordance with article 7:137 of the Code of Companies and Associations, shareholders who participate in the Shareholders' Meeting in this way shall be deemed to be present at the place where the Shareholders' Meeting is held for compliance with the quorum and majority requirements. The Lumi Connect platform enables Syensqo SA to control the quality and identity of shareholders.

RIGHT TO ADD AGENDA ITEMS AND TO SUBMIT RESOLUTION PROPOSALS

In accordance with Article 7:130 of the Code of Companies and Associations, one or more shareholders holding (together) at least 3% of the share capital of Syensqo SA may have new items added to the agenda of the Shareholders' Meeting and may submit resolution proposals in relation to existing or new agenda items.

Shareholders who wish to exercise this right must (a) provide evidence of ownership of such shareholding as at the date of their request and (b) record their shares representing such shareholding on the record date (i.e. on Tuesday 22 April 2025) in accordance with the above admission conditions. Evidence of ownership of such shareholding can be provided by a certificate evidencing the registration of the relevant shares in the share register of Syensqo SA (for registered shares) or by a certificate issued by an authorized account holder or a settlement organization certifying that the relevant number of dematerialised shares is recorded in the shareholder's account.

The request to add agenda items or resolution proposals must be made in writing and must be accompanied by, as the case may be, the text of the items to be added to the agenda and the corresponding resolution proposals, or the text of the newly proposed resolutions in relation to existing agenda items. Such request must contain a postal or e-mail address to which Syensqo SA will send an acknowledgement of receipt within 48 hours of receipt of such request.

The additional agenda items and/or resolution proposals must be received by Syensqo SA no later than Monday 14 April 2025 either by regular mail to the address of its registered office: Syensqo SA, Shareholders' Meeting, 98 rue de la Fusée at 1130 Brussels, or by email to the e-mail address: ag@syensqo.com.

If Syensqo SA receives such requests or submissions, it will publish, by Tuesday 22 April 2025 at the latest, an amended agenda for the Shareholders' Meeting, completed on the basis of all validly submitted requests and submissions, on its website (https://www.syensqo.com/en/investors/shareholders-meetings), in the Moniteur Belge and in the press. In this case, Syensqo SA will also make available a revised proxy form and a revised vote by correspondence form on its website (https://www.syensqo.com/en/investors/shareholders-meetings) and on the Lumi Connect platform (www.lumiconnect.com), simultaneously with the publication of the amended agenda of the Shareholders' Meeting.

In the event that shareholders, in accordance with Article 7:130 of the Companies and Associations Code, exercise their right to add items to the agenda and to submit resolution proposals, the proxy and vote by correspondence forms notified prior to the publication of the amended agenda will remain valid for the agenda items they cover. In the event that new/alternative proposals for resolutions are submitted in respect of existing agenda items subsequent to the proxy forms notified to Syensqo SA, the proxy holder shall abstain from voting on the new/alternative proposals for resolutions. However, in this case, shareholders will have the option of sending Syensqo SA a revised proxy or a revised vote by correspondence form.

RIGHT TO ASK QUESTIONS

Shareholders may submit written questions prior to the Shareholders' Meeting. Written questions will only be answered to the extent that the shareholder submitting them has complied with the above-mentioned conditions of admission in accordance with article 7:134 of the Code of Companies and Associations and if the written questions have been received by Syensqo SA by Wednesday 30 April 2025 at the latest, either by mail at the address of its registered office: Syensqo SA, Shareholders' Meeting, 98 rue de la Fusée, 1130 Brussels, or by e-mail: ag@syensqo.com.

For shareholders who choose to use the Lumi Connect platform, this platform also allows submitting the above-mentioned written questions. Answers to the written questions will be provided during the Shareholders' Meeting.

In addition, in accordance with article 7:139 of the Code of Companies and Associations, time will be allocated during the Shareholders' Meeting for a Q&A session during which directors will also answer questions addressed to them during the Shareholders' Meeting regarding their report or the items on the agenda. In addition to shareholders who physically attend the Shareholders' Meeting, shareholders who choose to participate and vote digitally at the Shareholders' Meeting via the Lumi Connect platform will be able to ask questions during the Shareholders' Meeting. They will be able to submit their questions live in writing via the Lumi Connect platform; they will be grouped and dealt with by topic.

AVAILABILITY OF DOCUMENTS

In accordance with Article 7:132 of the Code of Companies and Associations, each shareholder has the right to obtain free of charge, upon presentation of their security or of a certificate issued by an authorized account holder or a settlement organization certifying the number of dematerialised securities recorded in the name of the security holder, obtain at the registered office of Syensqo SA, i.e. 98 rue de la Fusée, 1130 Brussels, on business days and during normal office hours as from the date of publication of this convening notice, copies of the documents that relate to the Shareholders' Meeting and that must be made available to them pursuant to law, including this convening notice, the agenda, the resolution proposals of the Shareholders' Meeting and the proxy form or vote by correspondence form.

These documents are also available on Syensqo SA's website (https://www.syensqo.com/en/investors/shareholders-meetings).

These documents are also available on the Lumi Connect platform (except for the proxy form and the vote by correspondence form).

PROTECTION OF PERSONAL DATA

Syensqo SA is responsible for processing the personal data it receives from shareholders and proxy holders in the context of the Shareholders' Meeting in accordance with the applicable data protection laws, including the European Regulation 2016/679 of 27 April 2016 on the protection of natural persons with regard to the processing of personal data and on the free movement of such data (GDPR).

This personal data consists mainly of identification data of shareholders, their representatives or proxy holders, contact data (e.g. postal address, telephone number, e-mail address), number and type of shares, intention to participate, attendance at the Shareholders' Meeting, questions asked, votes cast, etc.

This data will be used to prepare and manage the attendance and voting process for the Shareholders' Meeting, as described in the convening notice, and will be passed on to third parties assisting the company for the above purposes, in particular Lumi. This processing of personal data is necessary in order to meet the legal obligations of Syensqo SA. If Syensqo SA does not process this personal data, it will not be able to allow the person concerned to be present or to be represented at the Shareholders' Meeting and/or to register the vote as a shareholder of Syensqo SA.

This information will not be kept longer than necessary for the same purposes, i.e. 10 years after the Shareholders' Meeting.

For more information, shareholders and proxy holders can consult our "Data Protection and Privacy Policy" via the link https://www.syensqo.com/en/information/data-protection-and-privacy-policy.html.

As set out in our Data Protection Policy referred to above, you also have rights with respect to your personal data in accordance with the applicable legal conditions and limits, namely the right of access to your personal data, the rectification or deletion thereof, as well as the right to restrict processing, the right to object to processing, the right to data portability and the right to lodge a complaint with the competent supervisory authority - in Belgium, the Data Protection Authority.

You can exercise your rights mentioned above by contacting Syensqo SA, 98 rue de la Fusée - 1130 Brussels (Belgium) (tel: +32 (0) 2 264 19 12 / e-mail: ag@syensqo.com).

Best regards.

Rosemary Thorne Chair of the Board of Directors

Useful information: Syensqo SA Assemblée Générale – Shareholders' Meeting 98 rue de la Fusée 1130 Brussels E-mail: ag@syensqo.com Hot Line: +32-(0)2.264.19 14 Enterprise number : 0798. 896.453 (RLE Brussels) Website: https://www.syensqo.com/en/investors/shareholders-meetings