Notification of a change in shareholding according to

Tekla Corporation Stock exchange release May 9, 2011 at 6:45
p.m.

Notification of a change in shareholding according to Securities Markets Act 2:9

According to the Securities Markets Act, Tekla Corporation has today received
the following notification on an agreement which, if executed in due course
leads to a change in holdings of the company:

Trimble Navigation Ltd. today on 9 May 2011 announced a public tender offer, to
be made by its subsidiary Trimble Finland Oy, for all issued and outstanding
shares in Tekla Corporation. The offer period for the tender offer is expected
to commence on May 19, 2011 and expire on June 17, 2011. Tekla holds a total of
96,600 of its own shares, representing 0.43 percent of all the shares and voting
rights in the company. These shares have been excluded from the tender offer.

Gerako Oy, holding approximately 38 percent of the shares and votes in Tekla,
has given an irrevocable undertaking to accept the tender offer. In addition,
shareholders representing in the aggregate 23.4 percent of Tekla's shares and
votes have confirmed their support for the tender offer and undertaken to tender
their shares in the offer (unless a higher offer is available).

Following thresholds for notification have been increased:
- over five-tenths (irrevocable undertakings) and
- over two-thirds by public tender offer.

The stock of Tekla Corporation comprises a total of 22,586,200 shares.

Tekla Corporation

Timo Keinänen, CFO
phone 358 400 813 027,
firstname.lastname@tekla.com

Distribution: NASDAQ OMX Helsinki Ltd, main media

Tekla Corporation

Tekla Corporation drives the evolution of digital information models with its
software, providing a growing competitive advantage to customers in the
construction, infrastructure and energy industries. Tekla's net sales for 2010
were nearly 58 million euros and operating result nearly 10 million euros.
International operations accounted for approximately 80% of net sales. Tekla has
customers in almost 100 countries, offices in 15 countries and a worldwide
partner network. Tekla Group currently employs approximately 500 persons, of
whom about 200 work outside of the headquarters in Finland. Tekla was
established in 1966, and is one of the longest-operating Finnish software
companies. www.tekla.com

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