Holding(s) in Company

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
BlackRock, Inc.
City of registered office (if applicable)
Wilmington
Country of registered office (if applicable)
USA
4. Details of the shareholder
Full name of shareholder(s) if different from the person(s) subject to the notification obligation, above

5. Date on which the threshold was crossed or reached
20-Sep-2024
6. Date on which Issuer notified
23-Sep-2024
7. Total positions of person(s) subject to the notification obligation

8. Notified details of the resulting situation on the date on which the threshold was crossed or reached
8A. Voting rights attached to shares

8B1. Financial Instruments according to (DTR5.3.1R.(1) (a))

8B2. Financial Instruments with similar economic effect according to (DTR5.3.1R.(1) (b))

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 BlackRock, Inc. (Chain 1) BlackRock Holdco 2, Inc. BlackRock, Inc. (Chain 1) BlackRock Financial Management, Inc. BlackRock, Inc. (Chain 1) BlackRock International Holdings, Inc. BlackRock, Inc. (Chain 1) BR Jersey International Holdings L.P. BlackRock, Inc. (Chain 1) BlackRock Holdco 3, LLC BlackRock, Inc. (Chain 1) BlackRock Cayman 1 LP BlackRock, Inc. (Chain 1) BlackRock Cayman West Bay Finco Limited BlackRock, Inc. (Chain 1) BlackRock Cayman West Bay IV Limited BlackRock, Inc. (Chain 1) BlackRock Group Limited BlackRock, Inc. (Chain 1) BlackRock Finance Europe Limited BlackRock, Inc. (Chain 1) BlackRock Investment Management (UK) Limited BlackRock, Inc. (Chain 2) BlackRock Holdco 2, Inc. BlackRock, Inc. (Chain 2) BlackRock Financial Management, Inc. BlackRock, Inc. (Chain 2) BlackRock International Holdings, Inc. BlackRock, Inc. (Chain 2) BR Jersey International Holdings L.P. BlackRock, Inc. (Chain 2) BlackRock Australia Holdco Pty. Ltd. BlackRock, Inc. (Chain 2) BlackRock Investment Management (Australia) Limited BlackRock, Inc. (Chain 3) BlackRock Holdco 2, Inc. BlackRock, Inc. (Chain 3) BlackRock Financial Management, Inc. BlackRock, Inc. (Chain 3) BlackRock Holdco 4, LLC BlackRock, Inc. (Chain 3) BlackRock Holdco 6, LLC BlackRock, Inc. (Chain 3) BlackRock Delaware Holdings Inc. BlackRock, Inc. (Chain 3) BlackRock Institutional Trust Company, National Association BlackRock, Inc. (Chain 4) BlackRock Holdco 2, Inc. BlackRock, Inc. (Chain 4) BlackRock Financial Management, Inc. BlackRock, Inc. (Chain 4) BlackRock Holdco 4, LLC BlackRock, Inc. (Chain 4) BlackRock Holdco 6, LLC BlackRock, Inc. (Chain 4) BlackRock Delaware Holdings Inc. BlackRock, Inc. (Chain 4) BlackRock Fund Advisors BlackRock, Inc. (Chain 5) BlackRock Holdco 2, Inc. BlackRock, Inc. (Chain 5) BlackRock Financial Management, Inc. BlackRock, Inc. (Chain 5) BlackRock International Holdings, Inc. BlackRock, Inc. (Chain 5) BlackRock Canada Holdings ULC BlackRock, Inc. (Chain 5) BlackRock Asset Management Canada Limited BlackRock, Inc. (Chain 6) BlackRock Holdco 2, Inc. BlackRock, Inc. (Chain 6) BlackRock Financial Management, Inc. BlackRock, Inc. (Chain 6) BlackRock International Holdings, Inc. BlackRock, Inc. (Chain 6) BR Jersey International Holdings L.P. BlackRock, Inc. (Chain 6) BlackRock Holdco 3, LLC BlackRock, Inc. (Chain 6) BlackRock Cayman 1 LP BlackRock, Inc. (Chain 6) BlackRock Cayman West Bay Finco Limited BlackRock, Inc. (Chain 6) BlackRock Cayman West Bay IV Limited BlackRock, Inc. (Chain 6) BlackRock Group Limited BlackRock, Inc. (Chain 6) BlackRock Finance Europe Limited BlackRock, Inc. (Chain 6) BlackRock Advisors (UK) Limited

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

11. Additional Information
BlackRock Regulatory Threshold Reporting Team

020 7743 3650
12. Date of Completion
23^rd September 2024
13. Place Of Completion
12 Throgmorton Avenue, London, EC2N 2DL, U.K.