Ahlstrom Corporation STOCK EXCHANGE ANNOUNCEMENT 09 December 2010 REPURCHASE OF OWN SHARES Date: 09 December 2010 Exchange transaction: Buy Share class: AHL1V Amount: 2500 Average price /share: 14.7426 EUR Highest price /share: 14.8000 EUR Lowest price /share: 14.7200 EUR Total price: 36856.50 EUR The shares held by Ahlstrom Corporation on 09 December 2010 AHL1V 148458 AHLSTROM CORPORATION On behalf of Ahlstrom Corporation Teemu Koivisto EVLI BANK PLC