OSB GROUP PLC - 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
    Lorentzweiler Adjacent Partners S.C.Sp.

City of registered office (if applicable)
    Howald

Country of registered office (if applicable)

    Luxembourg

4. Details of the shareholder

    Full name of shareholder(s) if different from the person(s) subject to the notification obligation, above

    City of registered office (if applicable) Country of registered office (if applicable)

5. Date on which the threshold was crossed or reached

    15-Sep-2026

6. Date on which Issuer notified
    16-Sep-2026

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

% of voting rights attached

% of voting rights through financial

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

Total number of voting rights held in issuer

	to shares (total of 8.A)	instruments (total of 8.B 1 + 8.B 2)
Resulting situation on the date on which threshold was crossed or reached	5.087900	0.000000	5.087900	17238397
Position of previous notification (if applicable)	4.019900	0.000000	4.019900

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	17238397	0	5.087900	0.000000
Sub Total 8.A	17238397		5.087900%

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
Sub Total 8.B2

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

% of voting rights through financial instruments if it equals or is

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

		notifiable threshold	higher than the notifiable threshold
Alan Waxman		3.096900		3.096900%
Alan Waxman	Sixth Street Partners Management Company, L.P.	3.096900		3.096900%
Alan Waxman	TAO Finance 3, LLC	1.858100		1.858100%
Alan Waxman	Beacon Finance 3, LLC	0.619400		0.619400%
Alan Waxman	Sixth Street Madrone Strategic Holdings I, L.P	0.619400		0.619400%
Alan Waxman	Lorentzweiler Adjacent Partners, S.C.Sp (acting through its general partner, Lorentzweiler Adjacent Investments, S.à r.l.)	3.096900		3.096900%
Alan Waxman		4.019900		4.019900%
Alan Waxman	Sixth Street Partners Management Company, L.P.	4.019900		4.019900%
Alan Waxman	TAO Finance 3, LLC	2.411900		2.411900%
Alan Waxman	Beacon Finance 3, LLC	0.804000		0.804000%

Alan Waxman	Sixth Street Madrone Strategic Holdings I, L.P	0.804000		0.804000%
Alan Waxman	Lorentzweiler Adjacent Partners, S.C.Sp (acting through its general partner, Lorentzweiler Adjacent Investments, S.à r.l.)	4.019900		4.019900%
Alan Waxman		5.087900		5.087900%
Alan Waxman	Sixth Street Partners Management Company, L.P.	5.087900		5.087900%
Alan Waxman	TAO Finance 3, LLC	3.052800		3.052800%
Alan Waxman	Beacon Finance 3, LLC	1.017600		1.017600%
Alan Waxman	Sixth Street Madrone Strategic Holdings I, L.P	1.017600		1.017600%
Alan Waxman	Lorentzweiler Adjacent Partners, S.C.Sp (acting through its general partner, Lorentzweiler Adjacent Investments, S.à r.l.)	5.087900		5.087900%

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 If date does not apply, explain below

11.    Additional Information

12.    Date of Completion
        16-Sep-2026

13.    Place Of Completion
        Luxembourg