Share Buyback via Reverse Accelerated Bookbuild

Launch of Share Buyback via Reverse Accelerated Bookbuild

On 3 June 2026, Griffin Mining Ltd ("Griffin" or "the Company") announced a share buy-back programme for the repurchase of the Company's ordinary shares of $0.01 each ("Ordinary Shares") on market and on an ad hoc basis as determined by the Company (the "Existing Buy Back Programme"). The board granted authority to apply up to $15 million of the Company's funds in the purchase of up to 3.7 million Ordinary Shares in connection with the Existing Buy Back Programme, which is scheduled to continue until no later than 30 November 2026. It was stated that, after this date, the directors of the Company will consider a further Buy Back Programme and/or other means of returning excess funds to shareholders.

The Company has now engaged Panmure Liberum Limited ("Panmure Liberum") to implement a separate share buyback via a reverse accelerated bookbuild (the "RABB Buyback"). Pursuant to the RABB Buyback, Panmure Liberum will purchase, as principal, up to a maximum of either (a) $14 million or (b) 3.5 million Ordinary Shares (being up to 1.98 per cent. of the Company's issued Ordinary Shares) at a price per Ordinary Share to be determined based on the offers received in the RABB Buyback process (the "Purchase Price"). This arrangement is in accordance with the Company's authority to repurchase Ordinary Shares as detailed in the Company's bye laws as a Bermudian incorporated company.

The total allocated to be spent on both the Existing Buy Back Programme and the RABB Buyback will not exceed $15 million.

The RABB Buyback will commence immediately following this announcement and will be closed at 16:45 (BST) on 22 June 2026 (or other such time as the Company and Panmure Liberum agree). The final number of Ordinary Shares to be purchased, together with the Purchase Price will be agreed at the close of the RABB Buyback at the sole discretion of Griffin and Panmure Liberum, and the results of the RABB Buyback will be announced as soon as practicable thereafter. To the extent that the RABB Buyback is oversubscribed, orders will be scaled back (whether on a pro rata basis or otherwise) at the sole discretion of Griffin and Panmure Liberum.

CREST Shareholders wishing to sell Ordinary Shares as part of the RABB Buyback should inform their broker to contact Panmure Liberum before 16:45 (BST) on 22 June 2026. Panmure Liberum: +44 (0)20 7886 2738.

Purchase of the Company's Ordinary Shares pursuant to the RABB Buyback will take place following announcement of the result of the RABB Buyback.

The primary purpose of the RABB Buyback is to reduce the share capital of the Company. The Ordinary Shares purchased under the RABB Buyback will be cancelled.

The directors of the Company consider the RABB Buyback to be in the best interests of the Company and of its shareholders generally, with the implementation of the RABB Buyback expected to enhance earnings per share.

Any purchase of Ordinary Shares under the RABB Buyback will be carried out on the London Stock Exchange.

The person responsible for arranging the release of this announcement on behalf of the Company is

Roger Goodwin, Finance Director.