Ahlstrom Corporation STOCK EXCHANGE RELEASE May 31, 2012 at 11.00 Ahlstrom, a global high performance materials company, plans to close its plant in Barcelona, Spain. The plant, which manufactures products for advanced and transportation filtration businesses, has suffered from continued weakening demand in Southern Europe. The company estimates that about 30 employees will be affected starting from the second half of 2012. The Barcelona plant, part of the Filtration business area, is one of the Ahlstrom's smallest production units. The plant has a saturator and a converter unit for materials used in transportation and advanced filtration applications. In the future, customers will be served from Ahlstrom's other plants. The measures taken by Ahlstrom to improve the efficiency at the plant have unfortunately not proved sufficient. The company will make every effort in supporting employees affected by the changes. For more information, please contact: Liisa Nyyssönen Vice President, Communications Tel. +358 10 888 4757 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, medical gowns and drapes, wallcoverings, flooring, labels and food packaging. We have a leading market position in the businesses in which we operate. Our 5,200 employees serve customers in 28 countries on six continents. In 2011, Ahlstrom's net sales amounted to EUR 1.6 billion. The company's share is quoted on the NASDAQ OMX Helsinki. More information is available at www.ahlstrom.com. [HUG#1616175]