Vaisala - Company Announcement

Vaisala Corporation Board's Decision to Acquire Company's Own Shares by Contractual Trade

Vaisala Corporation Stock Exchange Release May 18, 2012 at 5:30 pm


Vaisala Corporation disclosed on May 3, 2012 upon the decision of the Board of
Directors to use the authorization granted by the Annual General Meeting of
Shareholders held on March 28, 2012 for acquiring the company's own series A
shares. A maximum total of 150,000 series A shares representing approximately
0.82% of the Company's total shares, 1.01% of all series A shares and 0.22% of
the total voting rights will be repurchased. The company has currently 14,700
treasury shares in its possession.

As announced on May 3, 2012 the shares are intended to be acquired through
public trading at the market price prevailing at the time of acquisition in
accordance with the rules of on the NASDAQ OMX Helsinki Ltd. Due to the minor
trading volume of the company's shares, the Board of Directors of Vaisala
Corporation has decided to acquire own shares by contractual trade and thus
deviate from the procedures referred to in Clauses 3.2.1 - 3.2.2 in accordance
with the NASDAQ OMX Helsinki Ltd's Clause 3.2.5 related to acquisition of own
shares. The acquisition of own shares according to the decided manner may lead
to the volume of the acquisition at that particular trading day being more than
50 % of the trading volume of that trading day.

The treasury shares to be repurchased will be primarily used in the company's
Performance Share Plan to be implemented in 2012.

Vantaa, May 18, 2012

Vaisala Corporation

The Board of Directors

Further information
Kjell Forsén, President and CEO, Tel. +358 400 757 948


About Vaisala
Vaisala is a global leader in environmental and industrial measurement. Building
on 75 years of experience, Vaisala contributes to a better quality of life by
providing a comprehensive range of innovative observation and measurement
products and services for chosen weather-related and industrial markets.
Headquartered in Finland, Vaisala employs approximately 1400 professionals
worldwide and is listed on the NASDAQ OMX Helsinki stock exchange.
www.vaisala.com

Distribution
NASDAQ OMX Helsinki Ltd.
Major media
www.vaisala.com


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