OSB GROUP PLC                                        

ISIN: GB00BLDRH360

25 October 2024

LEI number: 213800ZBKL9BHSL2K459

OSB GROUP PLC (the "Company”)

Transaction in Own Shares

The Company announces that on 24 October 2024 it had purchased a total of 186,721 of its ordinary shares of £0.01 each (the "ordinary shares") on the London Stock Exchange, through the Company's broker Citigroup Global Markets Limited as detailed below. The repurchased ordinary shares will be cancelled.

 London Stock ExchangeCBOE BXECBOE CXENumber of ordinary shares purchased126,51442,68117,526Highest price paid (per ordinary share)381.00p379.00p379.00pLowest price paid (per ordinary share)375.60p375.60p375.80pVolume weighted average price paid (per ordinary share)378.33p377.89p377.89p The purchases form part of the Company's share buyback programme announced on 05 September 2024.

Following settlement of the above purchases and cancellation of the purchased ordinary shares, the Company's total number of ordinary shares in issue shall be 376,714,009 ordinary shares.

No ordinary shares are held in treasury. Therefore, the total number of voting rights in the Company is 376,714,009.

In accordance with Article 5(1)(b) of Regulation (EU) No 596/2014 as incorporated into and implemented under English law (including by virtue of the European Union (Withdrawal) Act 2018), the detailed breakdown of individual trades made by Citigroup Global Markets Limited on behalf of the Company as part of the share buyback programme is set out below.

This announcement does not constitute, or form part of, an offer or any solicitation of an offer for securities in any jurisdiction.

Schedule of Purchases - Individual Transactions

Issuer NameOSB GROUP PLCLEI213800ZBKL9BHSL2K459ISINGB00BLDRH360Intermediary NameCitigroup Global Markets LimitedIntermediary CodeSBILGB2LTimezone GMT + 1CurrencyGBP

ISINTransaction Date Trade TimeCurrencyVolumePriceTrading VenueTransaction IDGB00BLDRH36024/10/202416:22:46GBp62377.60XLONxeaNOUFaMqXGB00BLDRH36024/10/202416:22:32GBp346377.60XLONxeaNOUFaM3fGB00BLDRH36024/10/202416:21:22GBp550377.80XLONxeaNOUFaKcWGB00BLDRH36024/10/202416:20:59GBp256378.00XLONxeaNOUFaK4UGB00BLDRH36024/10/202416:05:32GBp238377.60XLONxeaNOUFa7GWGB00BLDRH36024/10/202416:05:32GBp402377.80XLONxeaNOUFa7GcGB00BLDRH36024/10/202415:59:24GBp97377.80XLONxeaNOUFa1lIGB00BLDRH36024/10/202415:59:19GBp155377.80XLONxeaNOUFa1gQGB00BLDRH36024/10/202415:59:19GBp10377.80XLONxeaNOUFa1gSGB00BLDRH36024/10/202415:52:33GBp278377.80XLONxeaNOUFaBy1GB00BLDRH36024/10/202415:51:57GBp22377.80XLONxeaNOUFa8X2GB00BLDRH36024/10/202415:47:15GBp392377.80XLONxeaNOUFbroUGB00BLDRH36024/10/202415:40:12GBp251377.80XLONxeaNOUFbzYnGB00BLDRH36024/10/202415:40:02GBp292377.80XLONxeaNOUFbzohGB00BLDRH36024/10/202415:30:40GBp222377.80XLONxeaNOUFbZ7YGB00BLDRH36024/10/202415:26:52GBp384378.40XLONxeaNOUFbl8ZGB00BLDRH36024/10/202415:18:54GBp217378.40XLONxeaNOUFbNW0GB00BLDRH36024/10/202415:18:54GBp121378.40XLONxeaNOUFbNW2GB00BLDRH36024/10/202415:15:10GBp110378.60XLONxeaNOUFbI7$GB00BLDRH36024/10/202415:15:10GBp123378.60XLONxeaNOUFbI7zGB00BLDRH36024/10/202415:14:50GBp472378.60XLONxeaNOUFbIOXGB00BLDRH36024/10/202415:07:44GBp455379.60XLONxeaNOUFbTRkGB00BLDRH36024/10/202415:05:32GBp1,745379.80XLONxeaNOUFbOmxGB00BLDRH36024/10/202415:05:30GBp106380.40XLONxeaNOUFbOyVGB00BLDRH36024/10/202415:05:30GBp230380.20XLONxeaNOUFbO$bGB00BLDRH36024/10/202415:05:30GBp113380.20XLONxeaNOUFbO$dGB00BLDRH36024/10/202415:05:30GBp136380.40XLONxeaNOUFbO$XGB00BLDRH36024/10/202415:05:30GBp222380.40XLONxeaNOUFbO$ZGB00BLDRH36024/10/202415:05:30GBp3,936380.40XLONxeaNOUFbO$rGB00BLDRH36024/10/202415:05:30