Holding(s) in Company

NOTIFICATION OF MAJOR HOLDINGS (to be sent to the relevant issuer and to the FCA in Microsoft Word format if possible) i

1a. Identity of the issuer or the underlying issuer of existing shares to which voting rights are at-tached ii:

Jadestone Energy Plc

1b. Please indicate if the issuer is a non-UK issuer(please mark with an "X" if appropriate)

Non-UK issuer

2. Reason for the notification(please mark the appropriate box or boxes with an "X")

An acquisition or disposal of voting rights

X

An acquisition or disposal of financial instruments

An event changing the breakdown of voting rights

Other (please specify) iii:

3. Details of person subject to the notification obligation iv

Name

PT Prima Petroleum Energi

City and country of registered office (if applicable)

Jakarta, Indonesia

4. Full name of shareholder(s)(if different from 3.) v

Name

1. PT Darma Pertiwi Raya

2. PT Pilar Sukses Utama

City and country of registered office (if applicable)

1. Jakarta, Indonesia

2. Jakarta, Indonesia

5. Date on which the threshold was crossed or reached vi:

28/08/2026

6. Date on which issuer notified (DD/MM/YYYY):

02/09/2026

7. Total positions of person(s) subject to the notification obligation

% of voting rights at-tached to shares (to-tal of 8. A)

% of voting rights through financial instru-ments

(total of 8.B 1 + 8.B 2)

Total of both in % (8.A + 8.B)

Total number of voting rights held

in issuer (8.A + 8.B) vii

Resulting situation on the date on which threshold was crossed or reached

28.27789%

N/A

28.27789%

154,094,444

Position of previous notification (if applicable)

N/A

N/A

N/A

8. Notified details of the resulting situation on the date on which the threshold was crossed or reached viii

A: Voting rights attached to shares

Class/type of shares

ISIN code (if possible)

Number of voting rights ix

% of voting rights

Direct

(DTR5.1)

Indirect

(DTR5.2.1)

Direct

(DTR5.1)

Indirect

(DTR5.2.1)

GB00BLR71299

N/A

154,094,444

N/A

28.27789%

SUBTOTAL 8. A

B 1: Financial Instruments according to DTR5.3.1R (1) (a)

Type of financial in-strument

Expiration date x

Exercise/ Conversion Period xi

Number of voting rights that may be acquired if the instrument is exercised/converted.

% of voting rights

N/A

N/A

N/A

N/A

N/A

SUBTOTAL 8. B 1

N/A

N/A

B 2: Financial Instruments with similar economic effect according to DTR5.3.1R (1) (b)

Type of financial instrument

Expiration date x

Exercise/ Conversion Pe-riod xi

Physical or cash Settlement xii

Number of voting rights

% of voting rights

N/A

N/A

N/A

N/A

N/A

N/A

SUBTOTAL

8.B.2

N/A

N/A

9. Information in relation to the person subject to the notification obligation(please mark the applicable box with an "X")

Person subject to the notification obligation is not controlled by any natural person or legal entity and does not control any other undertaking(s) holding directly or indirectly an interest in the (underlying) issuer xiii

Full chain of controlled undertakings through which the voting rights and/or the

financial instruments are effectively held starting with the ultimate controlling natural person or legal entity (please add additional rows as necessary) xiv

X

Name xv

% of voting rights if it equals or is higher than the notifiable threshold

% of voting rights through financial in-struments if it equals or is higher than the

notifiable threshold

Total of both if it equals or is higher than the notifiable thresh-

old

Go Darmadi (chain 1)

13.90141%

N/A

N/A

PT Darma Pertiwi Raya (chain 1)

14.13896%

N/A

N/A

Paulus Utomo (chain 2)

13.90141%

N/A

N/A

PT Pilar Sukses Utama (chain 2)

14.13896%

N/A

N/A

PT Prima Petroleum Energi

28.27789%

N/A

N/A

10. In case of proxy voting, please identify:

Name of the proxy holder

N/A

The number and % of voting rights held

N/A

The date until which the voting rights will be held

N/A

11. Additional information xvi

Place of completion

London, England

Date of completion

02/09/2026