Ahlstrom to publish January-March 2011 interim report on April 28, 2011

Ahlstrom Corporation STOCK EXCHANGE RELEASE 18.4.2011 at 14.00 Ahlstrom Corporation will publish its January-March 2011 interim report on Thursday, April 28, 2011 approximately at 3 p.m. Finnish time (CET +1). Ahlstrom's President & CEO Jan Lång and CFO Seppo Parvi will present the interim report in a conference call in English on the same day at 5 p.m. Finnish time. To participate in the teleconference, please dial +358 (0)9 2319 4349 in Finland or +44 (0)20 7806 1950 outside Finland a few minutes before the conference begins. The confirmation code is 9434510. The event can also be viewed as a live audio webcast at www.ahlstrom.com. Registration is required. It is possible to participate in the Q & A session via teleconference or online. An on-demand audio webcast of the conference will be available on Ahlstrom's website for twelve months after the call. The presentation material will be available at www.ahlstrom.com > Investors > Reports and presentations > 2011 after the interim report has been published. In addition, CEO Lång and CFO Parvi will present the interim report in Finnish at a press and analyst conference in Helsinki on Friday, April 29 at 9.00 a.m. Finnish time. The conference will take place at event arena Bank, address Unioninkatu 20, 2(nd) floor. The name of the meeting room will be displayed on the display board in the lobby. For further information, please contact: Juho Erkheikki Manager, Financial Communications & IR +358 10 888 4731 Distribution: NASDAQ OMX Helsinki Main media www.ahlstrom.com 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, wipes, 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. This announcement is distributed by Thomson Reuters on behalf of Thomson Reuters clients. The owner of this announcement warrants that: (i) the releases contained herein are protected by copyright and other applicable laws; and (ii) they are solely responsible for the content, accuracy and originality of the information contained therein. Source: Ahlstrom Oyj via Thomson Reuters ONE [HUG#1507313]