Holding(s) in Company

Costain Group PLC

16 October 2026

 

TR-1: Standard form for notification of major holdings

1. Issuer Details

ISIN

GB00B64NSP76

Issuer Name

COSTAIN GROUP PLC

UK or Non-UK Issuer

UK

2. Reason for Notification

An acquisition or disposal of financial instruments

3. Details of person subject to the notification obligation

Name

Oasis Management Company Ltd.

City of registered office (if applicable)

Central

Country of registered office (if applicable)

Hong Kong

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

14-Oct-2026

6. Date on which Issuer notified

16-Oct-2026

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 reached	0.000000	13.031155	13.031155	33989800
Position of previous notification (if applicable)	0.000000	12.735679	12.735679

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)
Sub Total 8.A

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
Total Return Swap			Cash	33989800	13.031155
Sub Total 8.B2				33989800	13.031155%

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
Seth Hillel Fischer			13.031155	13.031155%
Oasis Management Company Ltd.			13.031155	13.031155%
Oasis Management Holdings Ltd.			13.031155	13.031155%

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-Oct-2026

13. Place Of Completion

Hong Kong

 

END