Ahlstrom - Tender offer

Ahlstrom acquires 49 percent stake in U.S. battery separator company Porous Power Technologies

Ahlstrom Corporation STOCK EXCHANGE RELEASE December 12, 2011 at 10.10

Ahlstrom, a global high-performance materials company, has signed an agreement
to invest in Porous Power Technologies, LLC ("Porous Power"), a Colorado, U.S.
based company developing technology for lithium-ion battery separators. Under
the agreement, Ahlstrom will subscribe for approximately 49% of the shares in
Porous Power while the remaining 51% of the shares will be held by the current
owners of Porous Power. Ahlstrom has an option to acquire the remaining shares
at a later stage.

Ahlstrom, together with Porous Power, will be offering a new generation of
separator solutions for safer batteries and capacitors in electric-drive
vehicles, e-bikes, portable electronics and utility-grade storage products.
Porous Power's current separator products are already being evaluated by battery
manufacturers around the world. The products for electric vehicles will be
commercially available in larger scale later.

Battery separators, which keep the positive and negative electrodes (anode and
cathode) from touching each other and short-circuiting, are vitally important in
the performance and safety of electric vehicles. Ahlstrom has been developing
lightweight nonwoven materials for lithium-ion membrane separators since 2008
and has worked closely with Porous Power for several years.

According to industry analysts, the overall market for lithium-ion battery
separators is expected to grow to USD 2.5 billion in 2020 (approx. EUR 1.9
billion), mainly driven by the demand for electric vehicles."In line with our strategy, we are seeking growth opportunities in unique
products, both in our existing businesses as well as in new technologies. Porous
Power's membrane technology has high potential and is a good fit with our
technology base. Ahlstrom will use its extensive know-how and experience in
automotive industry to respond to the market needs in the fast-evolving electric
vehicle business in particular," says Jan Lång, President and CEO, Ahlstrom.

The new investment will be part of Ahlstrom's Building and Energy Business Area.

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.

About Porous Power
Porous Power Technologies, LLC (www.porouspower.com and
http://twitter.com/PorousPower) makes electrode separators that reduce the cost
and improve the safety, performance, efficiency and life of lithium-ion
batteries, particularly large-format cells for electric vehicles, stationary
power and consumer electronics applications.


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