Holding(s) in Company

Holding(s) in Company

TR-1: Standard form for notification of major holdings

1. Issuer Details ISIN GB00BLDRH360 Issuer Name OSB GROUP PLC UK or Non-UK Issuer UK 2. Reason for Notification An acquisition or disposal of voting rights 3. Details of person subject to the notification obligation Name JPMorgan Asset Management Holdings Inc. City of registered office (if applicable) Wilmington Country of registered office (if applicable) United States of America 4. Details of the shareholder Name City of registered office Country of registered office JPMorgan Asset Management (UK) LimitedLondonUnited kingdom

5. Date on which the threshold was crossed or reached 23-Dec-2025 6. Date on which Issuer notified 24-Dec-2025 7. Total positions of person(s) subject to the notification obligation .% of voting rights attached to shares (total of 8.A) % of voting rights through financial instruments (total of 8.B 1 + 8.B 2) Total of both in % (8.A + 8.B) Total number of voting rights held in issuer Resulting situation on the date on which threshold was crossed or reached5.075175%0.257730%5.332905%18,997,685Position of previous notification (if applicable)5.003032%0.257441%5.260473% 

8. Notified details of the resulting situation on the date on which the threshold was crossed or reached 8A. Voting rights attached to shares Class/Type of shares ISIN code(if possible) Number of direct voting rights (DTR5.1) Number of indirect voting rights (DTR5.2.1) % of direct voting rights (DTR5.1) % of indirect voting rights (DTR5.2.1) GB00BLDRH360 18,079,560 5.075175%Sub Total 8.A18,079,5605.075175%

8B1. Financial Instruments according to (DTR5.3.1R.(1) (a)) Type of financial instrument Expiration date Exercise/conversion period Number of voting rights that may be acquired if the instrument is exercised/converted % of voting rights      Sub Total 8.B1   

8B2. Financial Instruments with similar economic effect according to (DTR5.3.1R.(1) (b)) Type of financial instrument Expiration date Exercise/conversion period Physical or cash settlement Number of voting rights % of voting rights Cash Settled - Equity SwapsN/AN/ACash918,1250.257730%Sub Total 8.B2 918,1250.257730%

9. Information in relation to the person subject to the notification obligation 2. 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 entities (please add additional rows as necessary) Ultimate controlling person Name of controlled undertaking % of voting rights if it equals or is higher than the notifiable threshold % of voting rights through financial instruments if it equals or is higher than the notifiable threshold Total of both if it equals or is higher than the notifiable threshold JPMorgan Asset Management Holdings IncJPMorgan Asset Management (UK) Limited5.052088% 5.090517%JPMorgan Asset Management Holdings IncJ.P. Morgan Investment Management Inc.   JPMorgan Asset Management Holdings Inc.JPMorgan Asset Management (Japan) Limited   JPMorgan Asset Management Holdings IncJ.P. Morgan Alternative Asset Management, Inc   JPMorgan Asset Management Holdings Inc.JPMorgan Asset Management (Asia Pacific) Limited   JPMorgan Asset Management Holdings Inc.JPMorgan Asset Management (Singapore) Limited   

10. In case of proxy voting Name of the proxy holder

The number and % of voting rights held

The date until which the voting rights will be held

11. Additional Information Chain of controlled undertakings:JPMorgan Asset Management Holdings IncJPMorgan Asset Management International Limited (100%)JPMorgan Asset Management (UK) Limited (100%)JPMorgan Asset Management Holdings IncJ.P. Morgan Investment Management Inc. (100%)JPMorgan Asset Management Holdings IncJPMorgan Asset Management (Asia) Inc. (100%)JPMorgan Asset Management (Japan) Limited (100%)JPMorgan Asset Management Holdings IncJ.P. Morgan Alternative Asset Management, Inc. (100%)JPMorgan Asset Management Holdings Inc.JPMorgan Asset Management (Asia) Inc. (100%)JPMorgan Asset Management (Asia Pacific) Limited (100%)JPMorgan Asset Management Holdings Inc.JPMorgan Asset Management (Asia) Inc. (100%)JPMorgan Asset Management (Singapore) Limited (100%) 12. Date of Completion 24-Dec-2025 13. Place Of Completion Hyderabad, India