MARIMACA COPPER CORP. — Director's Dealing 2026

May 17, 2026

marimaca COPPER CORK

News Release

Appendix 3Y Change of Director's Interest Notice

Vancouver, British Columbia & Perth, Australia, May 18, 2026 – Marimaca Copper Corp. ("Marimaca" or the "Company") (TSX: MARI) (ASX: MC2) attaches an Appendix 3Y Change of Director's Interest Notice for Michael Haworth.

The Company advises that the late lodgement of this Appendix 3Y was due to an administrative oversight and considers this to be an isolated incident. The Company has reminded directors of their disclosure obligations and is satisfied that it has in place appropriate corporate governance policies, systems and processes to ensure ongoing compliance with Listing Rules 3.19A and 3.19B, including arrangements with directors.

This announcement was authorised for lodgement by the Company Secretary.

Contact Information

For further information please visit www.marimaca.com or contact:

Tavistock
+44 (0) 207 920 3150
Emily Moss / Ruairi Millar
marimaca@tavistock.co.uk

---

Appendix 3Y

Change of Director's Interest Notice

Rule 3.19A.2

Appendix 3Y

Change of Director's Interest Notice

Information or documents not available now must be given to ASX as soon as available. Information and documents given to ASX become ASX's property and may be made public.

Introduced 30/09/01 Amended 01/01/11

Name of entity	Marimaca Copper Corp.
ARBN	683 017 094

We (the entity) give ASX the following information under listing rule 3.19A.2 and as agent for the director for the purposes of section 205G of the Corporations Act.

Name of Director	Michael John Haworth
Date of last notice	1 May 2026

Part 1 - Change of director's relevant interests in securities

In the case of a trust, this includes interests in the trust made available by the responsible entity of the trust

Note: In the case of a company, interests which come within paragraph (i) of the definition of "notifiable interest of a director" should be disclosed in this part.

Direct or indirect interest	Direct and Indirect
Nature of indirect interest (including registered holder)
Note: Provide details of the circumstances giving rise to the relevant interest.	Accuro Trustees (Jersey) Ltd as trustees of the Yorkshire Rose Trust. Michael Haworth is a beneficiary of the trust.
Date of change	26 January 2026
No. of securities held prior to change	Direct:
38,330 ordinary shares
20,000 restricted share units (RSUs)
Class	Ordinary shares
Number acquired	Direct: 15,356
Indirect: 145,722
Number disposed	-

• See chapter 19 for defined terms.

01/01/2011

Appendix 3Y Page 1

---

Appendix 3Y

Change of Director's Interest Notice

Value/Consideration Note: If consideration is non-cash, provide details and estimated valuation	No consideration was paid. The closing share price on the date of distribution was C$11.84.
No. of securities held after change	Direct: 53,686 ordinary shares 20,000 RSUs Indirect: 145,722 ordinary shares
Nature of change Example: on-market trade, off-market trade, exercise of options, issue of securities under dividend reinvestment plan, participation in buy-back	In-specie distribution of shares received from an investment fund.

Part 2 – Change of director’s interests in contracts

Note: In the case of a company, interests which come within paragraph (ii) of the definition of "notifiable interest of a director" should be disclosed in this part.

Detail of contract	N/A
Nature of interest	N/A
Name of registered holder (if issued securities)	N/A
Date of change	N/A
No. and class of securities to which interest related prior to change Note: Details are only required for a contract in relation to which the interest has changed	N/A
Interest acquired	N/A
Interest disposed	N/A
Value/Consideration Note: If consideration is non-cash, provide details and an estimated valuation	N/A
Interest after change	N/A

Part 3 – ${}^{+}$ Closed period

Were the interests in the securities or contracts detailed above traded during a +closed period where prior written clearance was required?	No
If so, was prior written clearance provided to allow the trade to proceed during this period?	N/A
If prior written clearance was provided, on what date was this provided?	N/A

• See chapter 19 for defined terms.

Appendix 3Y Page 2

01/01/2011