Ahlstrom Corporation STOCK EXCHANGE RELEASE 18.11.2011 at 11.50 Ahlstrom Corporation, a global high performance materials company, has completed the repurchase program of its own shares announced on September 15, 2011. The company acquired a total of 250,000 own shares at an average price of EUR 12.45 through public trading on the NASDAQ OMX Helsinki Exchange. The shares were acquired under the authorization granted by the Annual General Meeting 2011 for the implementation of the company's share-based incentive plan. Evli Bank plc acted as a stock broker in the repurchases. Ahlstrom's Board of Directors has an authorization to acquire 4,000,000 of the company's own shares, which is valid until the end of the 2012 Annual General Meeting. Ahlstrom currently holds a total of 269,005 own shares, corresponding to approximately 0.58 percent of the total shares and votes. For more information, please contact: Liisa Nyyssönen Vice President, Communications Tel. +358 10 888 4757 Seppo Parvi CFO Tel. +358 10 888 4768 Ahlstrom in brief Ahlstrom is a high performance materials company, partnering with leading businesses around the world to help them stay ahead. Our products are used in a large variety of everyday applications, such as filters, wallcovers, flooring, labels and food packaging. We have a leading market position in the businesses in which we operate. Our 5,700 employees serve customers in 26 countries on six continents. In 2010, Ahlstrom's net sales amounted to EUR 1.9 billion. The company's share is quoted on the NASDAQ OMX Helsinki. More information available atwww.ahlstrom.com. [HUG#1565020]