Mytilineos S A : Invitation to Extraordinary General Meeting

INVITATION

of the Shareholders of the Société Anonyme

MYTILINEOS S.A.

General Commercial Register (GEMI) No.: 000757001000

(the "Company")

to Extraordinary General Meeting

In accordance with the provisions of the law and the Company's Articles of Association, and following its resolution taken in its meeting of March 6th, 2024, the Board of Directors invites the Shareholders of the Company at an Extraordinary General Meeting to be held at 13:00 hours of Wednesday, March 27th, 2024 at the Company's offices at 8 Artemidos Str., Maroussi, Attica. In the event that the quorum required by law is not achieved, the Board of Directors hereby invites the Shareholders of the Company to a Repeat General Meeting at 13:00 hours of Tuesday April 2nd, 2024, such meeting to be held at the aforementioned venue.

AGENDA

SOLE ITEM: Renewal of approval and terms for acquisition of own shares

Ι. Right to participate at the General Meeting:

Right to participate and vote at the general meeting have only the natural persons or legal entities who have the status of shareholder at the beginning of the fifth (5th) day prior to the original general meeting, i.e. on March 22nd, 2024 (record date). The aforementioned record date applies in the case of postponed or repeated meeting, given that the adjourned meeting or repeated meeting is not more than thirty (30) days from the record date pursuant to article 124 par. 6 of law 4548/2018. It is noted that in the case of repeated general meeting no new invitation will be published, in accordance with the provisions of article 130 of law 4548/2018.

For the Company, shareholders who are entitled to participate in the general meeting and to exercise the right to vote are those that are registered on the record date in the Dematerialized Securities System (DSS) of the company "HELLENIC CENTRAL SECURITIES DEPOSITORY (ATHEXCSD)" or the ones identified as such based on the relevant date through registered intermediaries or other intermediaries in compliance with the provisions of the legislation (Law 4548/2018, Law 4569/2019, Law 4706/2020 and Regulation (EU) 2018/1212) as well as the Rulebook of Operation of the Hellenic Central Securities Depository (Government Gazette B/1007/16.03.2021).

Proof of shareholding status may be evidenced by any legal means and in any case based on information received by the Company electronically by ATHEXCSD, if the latter provides registration services, the participating and registered intermediaries in the central securities depository in any other case. A shareholder may participate in the General Meeting, based on the confirmations or notices of Articles 5 and 6 of Regulation (EU) 2018/1212, provided by the intermediary, unless the General Meeting refuses such participation for a material cause, which justifies its refusal, in compliance with the relevant statutory provisions (Article 19 (1), Law 4569/2018 and Article 124, Law 4548/2018).

Note that exercise of said rights does not presuppose blocking of the beneficiary's shares nor adherence to any other similar procedure, which restricts the possibility of the sale and transfer of such shares during the period between the record date and the relevant general meeting.

ΙΙ. Guidelines for the exercise of the voting rights through proxy:

1

Shareholders who are entitled to participate at the general meeting may cast their vote either in person or by proxy. Each shareholder may appoint up to three

1. proxies. Legal entities participate at the general meeting by appointing up to three (3) natural persons as their representatives. However, if a shareholder holds shares in the Company, which appear in more than one securities' account, such restriction does not prevent such shareholder to appoint different proxy for the shares that appear in each securities' account in relation to the general meeting. A shareholder may appoint a proxy for one or more general meetings and for specific timeframe. The proxy casts vote according to the instructions of the shareholder, if any. Non-compliance of the proxy with the received instructions does not affect the validity of the general meeting's resolutions, even if such proxy's vote was decisive for achieving the majority.

Forms of appointment of proxies are available to the shareholders on the Company's website: www.mytilineos.comand, in case a shareholder has no access to such forms, in hard copies at the Investors Relations Department of the Company (8 Artemidos street, Maroussi, Attica, tel. [phone]), which upon shareholder's request, may be furnished without any charge.

Forms of appointment as well as of revocation or replacement of the shareholder's representative are submitted to the Company's headquarters at the above address (8 Artemidos street, Maroussi, Attica, to the attention of Investors Relations Department) or sent via fax to ([phone] or via e-mail at [e-mail], at least forty eight

1. hours prior to the scheduled general meeting, i.e. by March 25th,
   2024 and at 13:00 the latest.

The proxy is obliged to notify the Company, prior to the commencement of the general meeting, of any specific fact, which might be useful to the shareholders, in their assessment of the risk the proxy serving interests other than their own. Conflict of interest may arise in particular in cases where the proxy: a) is a controlling shareholder of the Company or is a legal person or entity controlled by such shareholder; b) is a member of the Board of Directors or in general of the management of the Company or of a controlling shareholder, or of another legal person or entity controlled by such shareholder; c) is an employee or an auditor of the Company or of a controlling shareholder, or of another legal person or entity controlled by a controlling shareholder; d) is a spouse or a first degree relative of a natural person referred to in cases a to c above.

1. Guidelines for remote participation (in person or by proxy) in the general meeting or/and exercise of voting right beforethe general meeting

Without prejudice to the aforementioned provisions regarding appointment or revocation or replacement of proxy holders, any shareholder wishing to participate in the general meeting remotely, must fill in and submit to the Company the "Declaration Form of Remote Participation in the General Meeting - Proxy Holder Authorization", which is available on the Company's website: www.mytilineos.comand must be submitted to the Company's headquarters at the above address (8 Artemidos street, Maroussi, Attica, to the attention of Investors Relations Department) or sent via fax to ([phone] or via [e-mail], at least forty eight

1. hours prior to the scheduled general meeting, i.e. by March 25th,
   2024 and at 13:00 the latest. Shareholders are advised to confirm successful dispatch and receipt by the Company of the "Declaration Form of Remote Participation in the General Meeting - Proxy Holder Authorization" by contacting the Company's Investors Relations Department (tel. [phone]).

2

Following verification of the shareholder's capacity, the shareholder (or its appointed proxy holder) shall be promptly furnished with instructions regarding attendance or/and voting during the general meeting.

In case the shareholder (or its proxy holder) wishes to vote on the items of the agenda beforethe general meeting, it shall fill in the "Voting Form", which is available on the Company's website: www.mytilineos.comand submit it to the Company via [e-mail], not later than twenty four (24) hours prior to the scheduled general meeting, i.e. by March 26th, 2024 and at 13:00 the latest. It is clarified that each shareholder may cast its vote either before or during the general meeting.

Each shareholder (or its proxy holder) may attend the general meeting (and participate in the voting) remotely using electronic means, from the meeting's commencement on March 27th, 2024 and 13:00 until its closing, by entering the link sent to the e-mail address identified in respective "Declaration Form of Remote Participation in the General Meeting - Proxy Holder Authorization". Each shareholder (or its proxy holder) may also address the general meeting by submitting questions either in writing at least forty-eight (48) hours prior to the scheduled general meeting (i.e. by March 25th, 2024 and at 13:00 the latest) to the Company's headquarters at the above address (8 Artemidos street, Maroussi, Attica, to the attention of Investors Relations Department) or sent via fax to ([phone] or via e-mail at [e-mail] during the meeting through electronic means.

It is noted that the meeting will be conducted in Greek, while interpretation in English will be also available for remote participants. The members of the board of directors, the internal audit director, as well as the persons provided under paragraphs 1 and 2 of article 127 of law 4548/2018, may participate in the general meeting remotely, as per above.

ΙV. Minority Rights:

According to article 121 paragraph 4 of law 4548/2018, the shareholders are being informed that, amongst others, they have the following rights provided for in article 141 paragraphs 2, 3, 6 and 7 of law 4548/2018:

1. Article 141 paragraph 2 of law 4548/2018: At the request of shareholders representing 1/20 of the paid-up share capital, the board of directors is obliged to include additional items in the agenda of the general meeting, provided that the relevant request is received by the board of directors at least fifteen (15) days prior to the general meeting. The additional items must be published or disclosed under the responsibility of the board of directors in accordance with article 122 of law 4548/2018 at least seven (7) days prior to the general meeting. The request to include additional items in the agenda must be accompanied by a justification or by a draft decision to be adopted by the general meeting. The revised agenda must be published in the same manner as the previous agenda, thirteen (13) days before the date of the general meeting and at the same time must be also made available to shareholders on the Company's website, along with the justification or the draft decision submitted by the shareholders, in accordance with article 123 paragraph 4 of law 4548/2018. If these additional items are not published, the requesting shareholders are entitled to request the adjournment of the general meeting in accordance with article 141 paragraph 5 of law 4548/2018 and to make the publication themselves, in accordance with the second subparagraph of this paragraph (and article 141 paragraph 2 of law 4548/2018) at Company's expense.
2. Article 141 paragraph 3 of law 4548/2018: Shareholders representing 1/20 of the paid-up share capital, have the right to submit draft decisions which have been included in the initial or revised agenda of the general meeting. Such

3

request must be furnished to the board of directors at least seven (7) days before the date of the general meeting, and said draft decisions are made available to the shareholders according to the provisions of article 123 paragraph 3 of law 4548/2018 at least six (6) days before the general meeting.

1. Article 141 paragraph 6 of law 4548/2018: Following a request submitted to the Company by any shareholder at least five (5) full days prior to the general meeting, the board of directors is obliged to provide to the general meeting the requested specific information on the Company's affairs, to the extent that this may be useful for the assessment of the items on the agenda. The board of directors may provide a single response to shareholders' requests with the same content. The obligation to provide information does not apply in the event that the information requested is already available on the Company's website, especially in the form of questions and answers. At the request of shareholders representing 1/20 of the paid-up share capital, the board of directors is obliged to announce to the ordinary general meeting the amounts that have been paid during the last two years to each member of the board of directors or to the
   Company's managers, as well as any benefits that were granted to them for any reason or on the basis of their contract with the Company. In all the above cases, the board of directors may refuse to provide such information for substantive ground, as recorded in the minutes. Such a reason may be, in the circumstances, the representation of the requesting shareholders to the board, in accordance with articles 79 or 80 of law 4548/2018. In the cases of this paragraph, the board of directors may respond in a single application to shareholders with the same content.
2. Article 141 paragraph 6 of law 4548/2018: At the request of shareholders representing at least one tenth (1/10) of the paid-up capital which is submitted to the Company within the period referred to in article 141 paragraph 6 of law 4548/2018, the board of directors is obliged to provide to the general meeting information on the course of the corporate affairs and assets of the Company. The board of directors may refuse to provide such information for substantive ground, as recorded in the minutes. Such a reason might be, as the case may be, the representation of the applicant shareholders on the Board, in accordance with articles 79 or 80 of law 4548/2018, provided that the respective members of the board of directors have received relevant information sufficiently.
3. Article 141 paragraph 8 of law 4548/2018: In the cases referred to in article 141 paragraphs 6 and 7 of law 4548/2018, any question as to the merits or not of the grounds of refusal on the part of the board of directors to provide the requested information, shall be resolved by court's decision, issued in interim injunction proceedings. By the same decision, the court obliges the Company to provide the information denied. The decision is not subject to any legal remedies.

In all above cases, the requesting shareholders must prove their capacity as shareholders, as well as the number of shares they hold, during the exercise of their right, except for in case of the first subparagraph of paragraph 6 of article 141 of law 4548/2018. Proof of shareholder status is made by any legal means and in any case based on information received by the company from the central securities depository, if it provides registration services, or through the participating and registered intermediaries in the central securities depository in any other case.

V. Available documents & information:

This invitation, the documents to be submitted to the general meeting, the draft decisions for each item of the agenda, or if no draft decisions has been proposed for approval, comments of the board of directors as well as draft decisions that are proposed by the shareholders, in accordance with article 141 paragraph 3 of law 4548/2018, immediately upon the receipt thereof by the Company, the proxy

4

forms, the forms regarding remote participation or/and remote voting and other information as stipulated in article 123 paragraph 3 of law 4548/2018, as well as detailed information related to the referred minority rights and the conditions of their exercise, are made available on the company's website: www.mytilineos.comand in hard copy at the Company's premises (8 Artemidos street, Maroussi, Attica, 15125, tel. [phone] in accordance with the provisions of law 4548/2018.

Maroussi, March 6th, 2024

The Board of Directors

MYTILINEOS S.A.

5