10th July 2025
Costain Group PLC
Transaction in own shares
Costain Group PLC ("Costain", "the Group" or "the Company") announces that, in accordance with the terms of its share buyback programme (the "Buyback Programme") announced on 16th June 2025, it has purchased the following number of its ordinary shares of 1 pence each ("Ordinary Shares") on the London Stock Exchange through Investec.
| Date of Purchase | 9th July 2025 |
| Number of Ordinary Shares purchased | 37,568 |
| Weighted average price per day (pence) | 147.4146 |
| Highest price per share (pence) | 148.60 |
| Lowest price per share (pence) | 146.80 |
The purchased Ordinary Shares will be cancelled. The Company does not hold any Ordinary Shares in treasury.
Costain has now purchased 1,887,037 Ordinary Shares in aggregate for cancellation under the Buyback Programme. Following settlement of the above purchases and cancellation of the purchased Ordinary Shares, the Group's total number of Ordinary Shares in issue will be 271,111,438 Ordinary Shares.
Details of Trades:
Aggregate information
| Venue | Volume-weighted average price (p) | Aggregated volume | Lowest price per share (p) | Highest price per share (p) |
| XLON | 147.4146 | 37,568 | 146.80 | 148.60 |
Individual Transactions
In accordance with Article 5(1)(b) of Regulation (EU) No 596/2014 as it applies in the UK (the Market Abuse Regulation), the table below contains detailed information of the individual trades made by Investec on behalf of Costain as part of the Buyback Programme.
| Date and time of each trade | Number of shares purchased | Price (pence per share) | Trading Venue | Transaction Reference Number |
| 09 July 2025 10:57:34 | 1,253 | 148.60 | XLON | 00343863072TRLO1 |
| 09 July 2025 10:57:34 | 626 | 148.60 | XLON | 00343863073TRLO1 |
| 09 July 2025 10:57:34 | 626 | 148.60 | XLON | 00343863074TRLO1 |
| 09 July 2025 10:57:34 | 626 | 148.60 | XLON | 00343863075TRLO1 |
| 09 July 2025 10:59:51 | 623 | 148.60 | XLON | 00343864371TRLO1 |
| 09 July 2025 10:59:51 | 318 | 148.60 | XLON | 00343864372TRLO1 |
| 09 July 2025 11:33:49 | 1,305 | 148.20 | XLON | 00343867800TRLO1 |
| 09 July 2025 12:07:08 | 650 | 148.20 | XLON | 00343869925TRLO1 |
| 09 July 2025 12:11:22 | 638 | 148.00 | XLON | 00343870036TRLO1 |
| 09 July 2025 12:32:15 | 638 | 147.80 | XLON | 00343871273TRLO1 |
| 09 July 2025 12:48:10 | 649 | 147.80 | XLON | 00343872038TRLO1 |
| 09 July 2025 13:18:14 | 1,273 | 147.00 | XLON | 00343873345TRLO1 |
| 09 July 2025 13:18:14 | 1 | 147.00 | XLON | 00343873346TRLO1 |
| 09 July 2025 13:18:14 | 636 | 147.00 | XLON | 00343873347TRLO1 |
| 09 July 2025 13:40:21 | 2,257 | 147.00 | XLON | 00343874269TRLO1 |
| 09 July 2025 13:40:21 | 327 | 147.00 | XLON | 00343874270TRLO1 |
| 09 July 2025 13:40:21 | 2,608 | 146.80 | XLON | 00343874271TRLO1 |
| 09 July 2025 13:40:29 | 1 | 147.00 | XLON | 00343874273TRLO1 |
| 09 July 2025 13:40:29 | 142 | 147.00 | XLON | 00343874274TRLO1 |
| 09 July 2025 13:40:29 | 13 | 147.00 | XLON | 00343874275TRLO1 |
| 09 July 2025 13:40:29 | 11 | 147.00 | XLON | 00343874276TRLO1 |
| 09 July 2025 13:47:29 | 264 | 147.20 | XLON | 00343874574TRLO1 |
| 09 July 2025 13:47:29 | 203 | 147.20 | XLON | 00343874575TRLO1 |
| 09 July 2025 13:47:29 | 361 | 147.20 | XLON | 00343874576TRLO1 |
| 09 July 2025 13:47:29 | 2,115 | 147.20 | XLON | 00343874577TRLO1 |
| 09 July 2025 13:47:29 | 1,797 | 147.20 | XLON | 00343874578TRLO1 |
| 09 July 2025 13:47:29 | 1,286 | 147.20 | XLON | 00343874579TRLO1 |
| 09 July 2025 13:47:29 | 234 | 147.20 | XLON | 00343874580TRLO1 |
| 09 July 2025 13:47:29 | 1,143 | 147.20 | XLON | 00343874581TRLO1 |
| 09 July 2025 13:47:29 | 336 | 147.20 | XLON | 00343874582TRLO1 |
| 09 July 2025 13:47:29 | 1,625 | 147.20 | XLON | 00343874583TRLO1 |
| 09 July 2025 13:47:29 | 381 | 147.20 | XLON | 00343874584TRLO1 |
| 09 July 2025 13:47:29 | 291 | 147.20 | XLON | 00343874585TRLO1 |
| 09 July 2025 13:47:29 | 388 | 147.20 | XLON | 00343874586TRLO1 |
| 09 July 2025 13:47:29 | 385 | 147.20 | XLON | 00343874587TRLO1 |
| 09 July 2025 13:47:29 | 351 | 147.20 | XLON | 00343874588TRLO1 |
| 09 July 2025 13:47:29 | 369 | 147.20 | XLON | 00343874589TRLO1 |
| 09 July 2025 13:47:29 | 349 | 147.20 | XLON | 00343874590TRLO1 |
| 09 July 2025 13:47:30 | 398 | 147.20 | XLON | 00343874595TRLO1 |
| 09 July 2025 13:48:16 | 343 | 147.20 | XLON | 00343874618TRLO1 |
| 09 July 2025 13:48:16 | 504 | 147.00 | XLON | 00343874619TRLO1 |
| 09 July 2025 14:07:05 | 673 | 147.00 | XLON | 00343875548TRLO1 |
| 09 July 2025 14:59:52 | 1,526 | 147.60 | XLON | 00343879263TRLO1 |
| 09 July 2025 14:59:55 | 231 | 147.60 | XLON | 00343879268TRLO1 |
| 09 July 2025 15:10:02 | 50 | 147.60 | XLON | 00343880117TRLO1 |
| 09 July 2025 15:10:02 | 884 | 147.60 | XLON | 00343880118TRLO1 |
| 09 July 2025 15:10:02 | 1,084 | 147.60 | XLON | 00343880119TRLO1 |
| 09 July 2025 15:17:11 | 654 | 147.40 | XLON | 00343880556TRLO1 |
| 09 July 2025 15:29:15 | 647 | 147.40 | XLON | 00343881454TRLO1 |
| 09 July 2025 15:29:15 | 647 | 147.40 | XLON | 00343881455TRLO1 |
| 09 July 2025 15:43:24 | 1,883 | 147.00 | XLON | 00343882721TRLO1 |
| 09 July 2025 15:43:24 | 628 | 147.00 | XLON | 00343882722TRLO1 |
| 09 July 2025 15:43:24 | 317 | 147.00 | XLON | 00343882723TRLO1 |
Enquiries:
| Investors and analysts Matt Jones, Costain
| Matt.Jones@costain.com +44 (0) 7860 922 341 |
| Financial media - Headland Andy Rivett-Carnac Charlie Twigg | costain@headlandconsultancy.com +44 (0) 7968 997365 +44 (0) 7946 494568 |
Issuer name: Costain Group PLC
LEI: 213800PKIJBZ2EDTKC88
ISIN: GB00B64NSP76
Classification: 2.4. Acquisition or disposal of the issuer's own shares
Intermediary name: Investec
Intermediary Code: MIDLGB22XXX
Timezone: BST
Currency: GBp
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