People

Sonja Siggberg

Partner

Sonja's practice includes capital markets transactions and other transactions involving listed companies as well as corporate governance related matters. She has advised clients in a number of equity and debt capital market transactions (both domestic and international), including IPOs, secondary share issues, complex corporate transactions, public takeovers and bond issues. She is also a trusted advisor in disclosure, insider and corporate governance matters as well as other securities markets related regulatory matters.

She has a lot of experience and her work is of excellent quality.

Capital Markets | Chambers Global, 2023


References

Parties

Sampo plc and Topdanmark A/S

Transaction

Sampo plc's recommended public exchange offer for the shares in Topdanmark A/S

Deal Value

DKK 33 billion

Role

Counsel to Sampo plc

Sonja Siggberg

Sonja Siggberg

Partner
sonja.siggberg@hannessnellman.com
Mikko Heinonen

Mikko Heinonen

Partner
mikko.heinonen@hannessnellman.com
Jon Termonen

Jon Termonen

Managing Associate
jon.termonen@hannessnellman.com
Robert Gordin

Robert Gordin

Senior Associate
robert.gordin@hannessnellman.com
Aki Salmela

Aki Salmela

Senior Associate
aki.salmela@hannessnellman.com
Samuel Åkerlund

Samuel Åkerlund

Associate
samuel.akerlund@hannessnellman.com
Tobias Palmgren

Tobias Palmgren

Associate
tobias.palmgren@hannessnellman.com
Sofi Lehtinen

Sofi Lehtinen

Associate
sofi.lehtinen@hannessnellman.com
Roope Sevón

Roope Sevón

Associate
roope.sevon@hannessnellman.com
Semmi Seljavaara

Semmi Seljavaara

Associate
semmi.seljavaara@hannessnellman.com
Heikki Vesikansa

Heikki Vesikansa

Partner
heikki.vesikansa@hannessnellman.com
Harri Vehviläinen

Harri Vehviläinen

Specialist Partner
harri.vehvilainen@hannessnellman.com
Isabella Kartila

Isabella Kartila

Senior Associate
isabella.kartila@hannessnellman.com
Johanna Haltia-Tapio

Johanna Haltia-Tapio

Specialist Partner
johanna.haltia-tapio@hannessnellman.com
Annika Sillanpää

Annika Sillanpää

Associate
annika.sillanpaa@hannessnellman.com
Mikko Huimala

Mikko Huimala

Partner
mikko.huimala@hannessnellman.com
Anders Bygglin

Anders Bygglin

Partner
anders.bygglin@hannessnellman.com
Aleksiina Markkula

Aleksiina Markkula

Associate
aleksiina.markkula@hannessnellman.com
Jesper Nevalainen

Jesper Nevalainen

Partner
jesper.nevalainen@hannessnellman.com
Lasse Riski

Lasse Riski

Specialist Partner
lasse.riski@hannessnellman.com
Anni Ollus

Anni Ollus

Senior Legal Assistant
anni.ollus@hannessnellman.com
Melisa Göllü

Melisa Göllü

Legal Assistant
melisa.gollu@hannessnellman.com
Anni Nohteri

Anni Nohteri

Legal Assistant
anni.nohteri@hannessnellman.com
Monika Parkkinen

Monika Parkkinen

Legal Assistant
monika.parkkinen@hannessnellman.com

Parties:

Kemppi Group Oy, Kempower Corporation

Transaction:

Counsel to Kemppi Group Oy, the majority owner of Kempower Corporation, in the placing of 3.4 million shares in Kempower Corporation

Deal value:

EUR 102 million

Role:

Counsel to Kemppi Group Oy

Sonja Siggberg

Sonja Siggberg

Partner
sonja.siggberg@hannessnellman.com
Mikko Heinonen

Mikko Heinonen

Partner
mikko.heinonen@hannessnellman.com
Tommi Kovero

Tommi Kovero

Senior Associate
tommi.kovero@hannessnellman.com
Sofi Lehtinen

Sofi Lehtinen

Associate
sofi.lehtinen@hannessnellman.com
Tobias Palmgren

Tobias Palmgren

Associate
tobias.palmgren@hannessnellman.com

Hannes Snellman advises NYAB Plc on its re-domiciliation and transfer of listing from Finland to Sweden. The re-domiciliation to Sweden is planned to be executed as a cross-border conversion, pursuant to the so-called EU Mobility Directive, whereby NYAB Plc, without being dissolved or liquidated, would be converted from a Finnish to a Swedish public limited liability company with its registered office in Sweden.

Sonja Siggberg

Sonja Siggberg

Partner
sonja.siggberg@hannessnellman.com
Linnea Lehtonen

Linnea Lehtonen

Senior Associate
linnea.lehtonen@hannessnellman.com
Heikki Vesikansa

Heikki Vesikansa

Partner
heikki.vesikansa@hannessnellman.com
Jenni Parviainen

Jenni Parviainen

Managing Associate
jenni.parviainen@hannessnellman.com
Sofia Ropo

Sofia Ropo

Senior Associate
sofia.ropo@hannessnellman.com

Parties:

Terveystalo Plc

Transaction: 

Counsel to Terveystalo Plc, a healthcare service provider listed on Nasdaq Helsinki, in the issue and listing of senior unsecured sustainability-linked notes. 

Value:

EUR 100 million

Role:

Counsel to Terveystalo Plc

Sonja Siggberg

Sonja Siggberg

Partner
sonja.siggberg@hannessnellman.com
Linnea Lehtonen

Linnea Lehtonen

Senior Associate
linnea.lehtonen@hannessnellman.com
Annemari Rosi

Annemari Rosi

Senior Associate
annemari.rosi@hannessnellman.com
Sofi Lehtinen

Sofi Lehtinen

Associate
sofi.lehtinen@hannessnellman.com
Markus Bremer

Markus Bremer

Partner
markus.bremer@hannessnellman.com
Pauliina Sutinen

Pauliina Sutinen

Senior Associate
pauliina.sutinen@hannessnellman.com

Parties:

Uponor Corporation (target), Georg Fischer Ltd (buyer)

Transaction: 

Counsel to Uponor Corporation in the recommended public cash tender offer by Georg Fischer Ltd to purchase all of the issued and outstanding shares of Uponor Corporation. 

Value:

EUR 2.1 billion

Role:

Counsel to Uponor Corporation

Mikko Heinonen

Mikko Heinonen

Partner
mikko.heinonen@hannessnellman.com
Klaus Ilmonen

Klaus Ilmonen

Partner, Doctor of Laws
klaus.ilmonen@hannessnellman.com
Sonja Siggberg

Sonja Siggberg

Partner
sonja.siggberg@hannessnellman.com
Aki Salmela

Aki Salmela

Senior Associate
aki.salmela@hannessnellman.com
Jon Termonen

Jon Termonen

Managing Associate
jon.termonen@hannessnellman.com
Viola Karjalainen

Viola Karjalainen

Associate
viola.karjalainen@hannessnellman.com
Roope Sevón

Roope Sevón

Associate
roope.sevon@hannessnellman.com
Wilma Montonen

Wilma Montonen

Associate
wilma.montonen@hannessnellman.com
Mikko Huimala

Mikko Huimala

Partner
mikko.huimala@hannessnellman.com
Päivi Tammilehto

Päivi Tammilehto

Counsel
paivi.tammilehto@hannessnellman.com
Helena Lamminen

Helena Lamminen

Senior Associate
helena.lamminen@hannessnellman.com
Essi Ellman

Essi Ellman

Associate
essi.ellman@hannessnellman.com
Sofia Saarelainen

Sofia Saarelainen

Associate
sofia.saarelainen@hannessnellman.com
 Annika  Grönholm

Annika Grönholm

Associate
annika.gronholm@hannessnellman.com
Heikki Vesikansa

Heikki Vesikansa

Partner
heikki.vesikansa@hannessnellman.com
Jenni Parviainen

Jenni Parviainen

Managing Associate
jenni.parviainen@hannessnellman.com
Harri Vehviläinen

Harri Vehviläinen

Specialist Partner
harri.vehvilainen@hannessnellman.com
Isabella Kartila

Isabella Kartila

Senior Associate
isabella.kartila@hannessnellman.com
Johanna Haltia-Tapio

Johanna Haltia-Tapio

Specialist Partner
johanna.haltia-tapio@hannessnellman.com
Melisa Göllü

Melisa Göllü

Legal Assistant
melisa.gollu@hannessnellman.com
Janika Manner

Janika Manner

Senior Legal Assistant
janika.manner@hannessnellman.com
Monika Parkkinen

Monika Parkkinen

Legal Assistant
monika.parkkinen@hannessnellman.com
Anni Nohteri

Anni Nohteri

Legal Assistant
anni.nohteri@hannessnellman.com

Parties:

Sega Europe Limited and SEGA Corporation (Buyers) Rovio Entertainment Corporation (Target)

Transaction:

Counsel to Sega Europe Limited and SEGA Corporation in the recommended public cash tender offer for all shares and options in Rovio Entertainment Corporation.

Deal value: 

Approximately EUR 706 million

Role:

Counsel to Sega Europe Limited and SEGA Corporation

Sonja Siggberg

Sonja Siggberg

Partner
sonja.siggberg@hannessnellman.com
Jon Termonen

Jon Termonen

Managing Associate
jon.termonen@hannessnellman.com
Sofi Lehtinen

Sofi Lehtinen

Associate
sofi.lehtinen@hannessnellman.com
Claes Backström

Claes Backström

Associate
claes.backstrom@hannessnellman.com
Samuel Åkerlund

Samuel Åkerlund

Associate
samuel.akerlund@hannessnellman.com
Satu Kokko

Satu Kokko

Senior Associate
satu.kokko@hannessnellman.com
Oliver Vesterlund

Oliver Vesterlund

Associate
oliver.vesterlund@hannessnellman.com
Viola Karjalainen

Viola Karjalainen

Associate
viola.karjalainen@hannessnellman.com
Heidi Haanpää

Heidi Haanpää

Partner
heidi.haanpaa@hannessnellman.com
Mikko Huimala

Mikko Huimala

Partner
mikko.huimala@hannessnellman.com
 Annika  Grönholm

Annika Grönholm

Associate
annika.gronholm@hannessnellman.com
Panu Siitonen

Panu Siitonen

Partner
panu.siitonen@hannessnellman.com
Hilma Mäkitalo-Saarinen

Hilma Mäkitalo-Saarinen

Associate
hilma.makitalo-saarinen@hannessnellman.com
Wilhelm Sanmark

Wilhelm Sanmark

Associate
wilhelm.sanmark@hannessnellman.com
Johanna Haltia-Tapio

Johanna Haltia-Tapio

Specialist Partner
johanna.haltia-tapio@hannessnellman.com
Ingrid Remmelgas

Ingrid Remmelgas

Counsel
ingrid.remmelgas@hannessnellman.com
Karoliina Kaartinen

Karoliina Kaartinen

Legal Assistant
karoliina.kaartinen@hannessnellman.com
Monika Parkkinen

Monika Parkkinen

Legal Assistant
monika.parkkinen@hannessnellman.com
Hanna-Mari Mudi

Hanna-Mari Mudi

Legal Assistant
hanna-mari.mudi@hannessnellman.com

Parties:

Cargotec Corporation, Konecranes Plc

Transaction:

The announced, but subsequently abandoned, merger of Cargotec and Konecranes in 2021-2022

Deal value:

Approx. EUR 2.7 billion

Role:

Counsel to Konecranes Plc

Mikko Heinonen

Mikko Heinonen

Partner
mikko.heinonen@hannessnellman.com
Sonja Siggberg

Sonja Siggberg

Partner
sonja.siggberg@hannessnellman.com
Mikko Huimala

Mikko Huimala

Partner
mikko.huimala@hannessnellman.com
Markus Bremer

Markus Bremer

Partner
markus.bremer@hannessnellman.com
Jenni Heurlin

Jenni Heurlin

Managing Associate
jenni.heurlin@hannessnellman.com
Johanna Haltia-Tapio

Johanna Haltia-Tapio

Specialist Partner
johanna.haltia-tapio@hannessnellman.com
Ingrid Remmelgas

Ingrid Remmelgas

Counsel
ingrid.remmelgas@hannessnellman.com
Matias Moberg

Matias Moberg

Managing Associate
matias.moberg@hannessnellman.com
Riikka Kuha

Riikka Kuha

Counsel
riikka.kuha@hannessnellman.com
Agda Vähä-Piikkiö

Agda Vähä-Piikkiö

Senior Associate
agda.vaha-piikkio@hannessnellman.com
Linnea Lehtonen

Linnea Lehtonen

Senior Associate
linnea.lehtonen@hannessnellman.com
Pauliina Sutinen

Pauliina Sutinen

Senior Associate
pauliina.sutinen@hannessnellman.com
Jenni Parviainen

Jenni Parviainen

Managing Associate
jenni.parviainen@hannessnellman.com
Heikki Vesikansa

Heikki Vesikansa

Partner
heikki.vesikansa@hannessnellman.com

Parties

The German State (Buyer), Fortum Oyj (Seller), Uniper SE (Target)

Transaction 

Fortum Oyj’s arrangements related to stabilisation of its German subsidiary Uniper SE. The package will ensure multi-billion funding for Uniper, sale of Fortum’s shareholding in Uniper to the German State for approximately EUR 0.5 billion as well as repayment of Fortum’s EUR 4 billion receivables from Uniper and release of EUR 4 billion parent company guarantees.

Deal value 

Approx. EUR 4.5 billion

Role 

Finnish counsel to Fortum Oyj

Mikko Heinonen

Mikko Heinonen

Partner
mikko.heinonen@hannessnellman.com
Antti Nyberg

Antti Nyberg

Partner
antti.nyberg@hannessnellman.com
Sonja Siggberg

Sonja Siggberg

Partner
sonja.siggberg@hannessnellman.com
Klaus Ilmonen

Klaus Ilmonen

Partner, Doctor of Laws
klaus.ilmonen@hannessnellman.com
Markus Bremer

Markus Bremer

Partner
markus.bremer@hannessnellman.com
Mikko Huimala

Mikko Huimala

Partner
mikko.huimala@hannessnellman.com
Jan Lilius

Jan Lilius

Specialist Partner
jan.lilius@hannessnellman.com
Mikko  Tavast

Mikko Tavast

Counsel
mikko.tavast@hannessnellman.com
Johanna Haltia-Tapio

Johanna Haltia-Tapio

Specialist Partner
johanna.haltia-tapio@hannessnellman.com
Matias Moberg

Matias Moberg

Managing Associate
matias.moberg@hannessnellman.com
Robert Gordin

Robert Gordin

Senior Associate
robert.gordin@hannessnellman.com
Sofi Lehtinen

Sofi Lehtinen

Associate
sofi.lehtinen@hannessnellman.com

Parties

Viking Line Abp

Transaction

Counsel to Viking Line Abp on its EUR 51.8 million issue of new shares with pre-emptive rights for existing shareholders.

Deal Value

EUR 51.8 million

Role

Counsel to Viking Line Abp

Sonja Siggberg

Sonja Siggberg

Partner
sonja.siggberg@hannessnellman.com
Klaus Ilmonen

Klaus Ilmonen

Partner, Doctor of Laws
klaus.ilmonen@hannessnellman.com
Markus Bremer

Markus Bremer

Partner
markus.bremer@hannessnellman.com
Hanna Lindberg

Hanna Lindberg

Associate
hanna.lindberg@hannessnellman.com
Stefan Stellato

Stefan Stellato

Managing Associate
stefan.stellato@hannessnellman.com

Parties

Altia Plc, Arcus ASA

Transaction

Merger of Altia Plc and Arcus ASA to form Anora Group

Deal value

Preliminary aggregated annual revenue EUR 640 million

Role

Lead counsel to Altia Plc

Sonja Siggberg

Sonja Siggberg

Partner
sonja.siggberg@hannessnellman.com
Klaus Ilmonen

Klaus Ilmonen

Partner, Doctor of Laws
klaus.ilmonen@hannessnellman.com
Anniina Järvinen

Anniina Järvinen

Partner
anniina.jarvinen@hannessnellman.com
Robert Gordin

Robert Gordin

Senior Associate
robert.gordin@hannessnellman.com
Mikko Huimala

Mikko Huimala

Partner
mikko.huimala@hannessnellman.com
Essi Ellman

Essi Ellman

Associate
essi.ellman@hannessnellman.com
Jenni Heurlin

Jenni Heurlin

Managing Associate
jenni.heurlin@hannessnellman.com
Heikki Vesikansa

Heikki Vesikansa

Partner
heikki.vesikansa@hannessnellman.com
Harri Vehviläinen

Harri Vehviläinen

Specialist Partner
harri.vehvilainen@hannessnellman.com
Isabella Kartila

Isabella Kartila

Senior Associate
isabella.kartila@hannessnellman.com
Markus Bremer

Markus Bremer

Partner
markus.bremer@hannessnellman.com
Johanna Haltia-Tapio

Johanna Haltia-Tapio

Specialist Partner
johanna.haltia-tapio@hannessnellman.com
Risto Ojakoski

Risto Ojakoski

Associate
risto.ojakoski@hannessnellman.com
Panu Siitonen

Panu Siitonen

Partner
panu.siitonen@hannessnellman.com

Parties 

Virala Acquisition Company Plc, Purmo Group Ltd

Transaction 

Virala Acquisition Company Plc's merger with Purmo Group Ltd.

Deal Value 

EUR 685 million

Role

Counsel to Virala Acquisition Company Plc

Sonja Siggberg

Sonja Siggberg

Partner
sonja.siggberg@hannessnellman.com
Anniina Järvinen

Anniina Järvinen

Partner
anniina.jarvinen@hannessnellman.com
Linnea Lehtonen

Linnea Lehtonen

Senior Associate
linnea.lehtonen@hannessnellman.com
Tommi Kovero

Tommi Kovero

Senior Associate
tommi.kovero@hannessnellman.com
Tero Pikkarainen

Tero Pikkarainen

Senior Associate
tero.pikkarainen@hannessnellman.com
Oliver Vesterlund

Oliver Vesterlund

Associate
oliver.vesterlund@hannessnellman.com
Heikki Vesikansa

Heikki Vesikansa

Partner
heikki.vesikansa@hannessnellman.com
Stefan Stellato

Stefan Stellato

Managing Associate
stefan.stellato@hannessnellman.com
Isabella Kartila

Isabella Kartila

Senior Associate
isabella.kartila@hannessnellman.com
Antti Nyberg

Antti Nyberg

Partner
antti.nyberg@hannessnellman.com
Pauliina Sutinen

Pauliina Sutinen

Senior Associate
pauliina.sutinen@hannessnellman.com
Axel Hård af Segerstad

Axel Hård af Segerstad

Associate
axel.hard@hannessnellman.com
Wilhelm Sanmark

Wilhelm Sanmark

Associate
wilhelm.sanmark@hannessnellman.com
Mikko Huimala

Mikko Huimala

Partner
mikko.huimala@hannessnellman.com
Jenni Heurlin

Jenni Heurlin

Managing Associate
jenni.heurlin@hannessnellman.com

Parties

Virala Acquisition Company Plc

Transaction

Hannes Snellman acted as legal counsel to Virala Acquisition Company Plc on its IPO and the listing of its Class C shares on the SPAC segment of the regulated market of Nasdaq Helsinki

Deal Value

EUR 107.5 million

Role

Counsel to Virala Acquisition Company Plc

Sonja Siggberg

Sonja Siggberg

Partner
sonja.siggberg@hannessnellman.com
Anniina Järvinen

Anniina Järvinen

Partner
anniina.jarvinen@hannessnellman.com
Sofi Lehtinen

Sofi Lehtinen

Associate
sofi.lehtinen@hannessnellman.com
Linnea Lehtonen

Linnea Lehtonen

Senior Associate
linnea.lehtonen@hannessnellman.com
Tommi Kovero

Tommi Kovero

Senior Associate
tommi.kovero@hannessnellman.com
Annemari Rosi

Annemari Rosi

Senior Associate
annemari.rosi@hannessnellman.com
Aki Salmela

Aki Salmela

Senior Associate
aki.salmela@hannessnellman.com
Heikki Vesikansa

Heikki Vesikansa

Partner
heikki.vesikansa@hannessnellman.com
Stefan Stellato

Stefan Stellato

Managing Associate
stefan.stellato@hannessnellman.com
Isabella Kartila

Isabella Kartila

Senior Associate
isabella.kartila@hannessnellman.com
Piia Ahonen

Piia Ahonen

Specialist Partner
piia.ahonen@hannessnellman.com
Marika Sorsa

Marika Sorsa

Counsel
marika.sorsa@hannessnellman.com
Antti Nyberg

Antti Nyberg

Partner
antti.nyberg@hannessnellman.com
Johanna Haltia-Tapio

Johanna Haltia-Tapio

Specialist Partner
johanna.haltia-tapio@hannessnellman.com

Parties

Vaaka Partners (Seller)

Transaction

Vaaka Partners' sale of their shares held in Musti Group Plc through an accelerated book-building process.

Deal Value

Value not public

Role

Counsel to Vaaka Partners

Sonja Siggberg

Sonja Siggberg

Partner
sonja.siggberg@hannessnellman.com
Anniina Järvinen

Anniina Järvinen

Partner
anniina.jarvinen@hannessnellman.com

Parties

Ahlstrom-Munksjö Oyj (target), a consortium consisting of Ahlström Capital, Bain Capital Private Equity, Viknum and Belgrano Inversiones (buyer)

Transaction

Recommended public cash tender offer for all shares in Ahlstrom-Munksjö Oyj by Spa Holdings 3 Oy

Deal value

Approximately EUR 2.1 billion

Role

Counsel to the consortium

Sonja Siggberg

Sonja Siggberg

Partner
sonja.siggberg@hannessnellman.com
Antti Kuha

Antti Kuha

Partner
antti.kuha@hannessnellman.com
Annemari Rosi

Annemari Rosi

Senior Associate
annemari.rosi@hannessnellman.com
Robert Gordin

Robert Gordin

Senior Associate
robert.gordin@hannessnellman.com
Heikki Vesikansa

Heikki Vesikansa

Partner
heikki.vesikansa@hannessnellman.com
Stefan Stellato

Stefan Stellato

Managing Associate
stefan.stellato@hannessnellman.com
Harri Vehviläinen

Harri Vehviläinen

Specialist Partner
harri.vehvilainen@hannessnellman.com
Helena Lamminen

Helena Lamminen

Senior Associate
helena.lamminen@hannessnellman.com
Antti Nyberg

Antti Nyberg

Partner
antti.nyberg@hannessnellman.com

Parties 

Local Tapiola Finance Ltd

Transaction

Local Tapiola Finance Ltd's issue of EUR 115,000,000 2-year senior unsecured floating rate notes

Deal Value

Value not public

Role

Counsel to Local Tapiola Finance Ltd

Pauliina Sutinen

Pauliina Sutinen

Senior Associate
pauliina.sutinen@hannessnellman.com
Sonja Siggberg

Sonja Siggberg

Partner
sonja.siggberg@hannessnellman.com
Annemari Rosi

Annemari Rosi

Senior Associate
annemari.rosi@hannessnellman.com

Parties

Cramo Plc, Adapteo Plc

Transaction

Cramo’s partial demerger and listing of Adapteo on Nasdaq Stockholm

Deal Value

SEK 5.5 billion

Role

Counsel to Cramo Plc and Adapteo Plc

Sonja Siggberg

Sonja Siggberg

Partner
sonja.siggberg@hannessnellman.com
Antti Kuha

Antti Kuha

Partner
antti.kuha@hannessnellman.com
Elina Toivakainen

Elina Toivakainen

Counsel
elina.toivakainen@hannessnellman.com
Linnea Lehtonen

Linnea Lehtonen

Senior Associate
linnea.lehtonen@hannessnellman.com
Markus Bremer

Markus Bremer

Partner
markus.bremer@hannessnellman.com
Stefan Stellato

Stefan Stellato

Managing Associate
stefan.stellato@hannessnellman.com

Parties

Ahlstrom-Munksjö

Transaction

Ahlstrom-Munksjö's EUR 150 million rights issue to partly finance the acquisition of Expera Specialty Solutions

Deal Value

EUR 150 million

Role

Counsel to Ahlstrom-Munksjö

Sonja Siggberg

Sonja Siggberg

Partner
sonja.siggberg@hannessnellman.com
Anniina Järvinen

Anniina Järvinen

Partner
anniina.jarvinen@hannessnellman.com
Annemari Rosi

Annemari Rosi

Senior Associate
annemari.rosi@hannessnellman.com
Elina Toivakainen

Elina Toivakainen

Counsel
elina.toivakainen@hannessnellman.com

Parties

LocalTapiola Mutual Life Insurance Company

Transaction

LocalTapiola Mutual Life Insurance Company’s issue of EUR 100 million capital notes

Deal Value

Value 100 million

Role

Counsel to LocalTapiola Mutual Life Insurance Company

Markus Bremer

Markus Bremer

Partner
markus.bremer@hannessnellman.com
Sonja Siggberg

Sonja Siggberg

Partner
sonja.siggberg@hannessnellman.com
Annemari Rosi

Annemari Rosi

Senior Associate
annemari.rosi@hannessnellman.com

Parties

Ahlstrom-Munksjö (Buyer), Expera Specialty Solutions (Target), KPS Capital Partners (Seller)

Transaction

Ahlstrom-Munksjö’s acquisition of Expera Specialty Solutions, a U.S.-based specialty paper producer

Deal Value

USD 615 million

Role

Counsel to Ahlstrom-Munksjö

Sonja Siggberg

Sonja Siggberg

Partner
sonja.siggberg@hannessnellman.com
Antti Kuha

Antti Kuha

Partner
antti.kuha@hannessnellman.com
Anniina Järvinen

Anniina Järvinen

Partner
anniina.jarvinen@hannessnellman.com
Agda Vähä-Piikkiö

Agda Vähä-Piikkiö

Senior Associate
agda.vaha-piikkio@hannessnellman.com

Parties

YIT Oyj

Transaction

Issue of EUR 100 million and EUR 150 million senior notes by YIT Oyj

Deal Value

EUR 250 million

Role

Counsel to YIT Oyj

Markus Bremer

Markus Bremer

Partner
markus.bremer@hannessnellman.com
Sonja Siggberg

Sonja Siggberg

Partner
sonja.siggberg@hannessnellman.com
Annemari Rosi

Annemari Rosi

Senior Associate
annemari.rosi@hannessnellman.com

Parties

The State of Finland (seller), Altia Plc (target)

Transaction

Altia Plc’s IPO and listing on the official list of Nasdaq Helsinki

Deal Value

Over EUR 270 million

Role

Counsel to Altia Plc

Sonja Siggberg

Sonja Siggberg

Partner
sonja.siggberg@hannessnellman.com
Markus Bremer

Markus Bremer

Partner
markus.bremer@hannessnellman.com
Anniina Järvinen

Anniina Järvinen

Partner
anniina.jarvinen@hannessnellman.com
Annemari Rosi

Annemari Rosi

Senior Associate
annemari.rosi@hannessnellman.com
Matias Moberg

Matias Moberg

Managing Associate
matias.moberg@hannessnellman.com

Parties

Suomen Terveystalo Oy

Transaction

Terveystalo’s IPO and listing on the Nasdaq Helsinki stock exchange

Deal Value

The offering by the company and its shareholders was over EUR 870 million and the Company’s market value was over EUR 1.2 billion

Role

Counsel to Terveystalo

Klaus Ilmonen

Klaus Ilmonen

Partner, Doctor of Laws
klaus.ilmonen@hannessnellman.com
Sonja Siggberg

Sonja Siggberg

Partner
sonja.siggberg@hannessnellman.com
Anniina Järvinen

Anniina Järvinen

Partner
anniina.jarvinen@hannessnellman.com
Antti Kuha

Antti Kuha

Partner
antti.kuha@hannessnellman.com
Ella Mäkijärvi

Ella Mäkijärvi

Senior Associate
ella.makijarvi@hannessnellman.com
Elina Toivakainen

Elina Toivakainen

Counsel
elina.toivakainen@hannessnellman.com
Markus Bremer

Markus Bremer

Partner
markus.bremer@hannessnellman.com
Matias Moberg

Matias Moberg

Managing Associate
matias.moberg@hannessnellman.com
Annemari Rosi

Annemari Rosi

Senior Associate
annemari.rosi@hannessnellman.com

Parties

Lemminkäinen Corporation and YIT Corporation

Transaction

The combination of Lemminkäinen Corporation and YIT Corporation through a statutory merger

Deal Value

EUR 771 million

Role

Counsel to Lemminkäinen

Sonja Siggberg

Sonja Siggberg

Partner
sonja.siggberg@hannessnellman.com
Mikko Heinonen

Mikko Heinonen

Partner
mikko.heinonen@hannessnellman.com
Markus Bremer

Markus Bremer

Partner
markus.bremer@hannessnellman.com
Heikki Vesikansa

Heikki Vesikansa

Partner
heikki.vesikansa@hannessnellman.com
Johanna Haltia-Tapio

Johanna Haltia-Tapio

Specialist Partner
johanna.haltia-tapio@hannessnellman.com
Elina Toivakainen

Elina Toivakainen

Counsel
elina.toivakainen@hannessnellman.com
Laura Tavakka

Laura Tavakka

Talent Development Coordinator
laura.tavakka@hannessnellman.com
Heikki Majamaa

Heikki Majamaa

Specialist Partner
heikki.majamaa@hannessnellman.com
Harri Vehviläinen

Harri Vehviläinen

Specialist Partner
harri.vehvilainen@hannessnellman.com
Jenni Heurlin

Jenni Heurlin

Managing Associate
jenni.heurlin@hannessnellman.com
Stefan Stellato

Stefan Stellato

Managing Associate
stefan.stellato@hannessnellman.com

Parties

Ahlstrom Oyj, Munksjö Oyj

Transaction

The combination of Ahlstrom and Munksjö through a merger

Deal Value

Approx. EUR 1,2 billion

Role

Lead counsel to Ahlstrom

Sonja Siggberg

Sonja Siggberg

Partner
sonja.siggberg@hannessnellman.com
Antti Kuha

Antti Kuha

Partner
antti.kuha@hannessnellman.com
Heikki Vesikansa

Heikki Vesikansa

Partner
heikki.vesikansa@hannessnellman.com
Johanna Haltia-Tapio

Johanna Haltia-Tapio

Specialist Partner
johanna.haltia-tapio@hannessnellman.com
Annemari Rosi

Annemari Rosi

Senior Associate
annemari.rosi@hannessnellman.com
Stefan Stellato

Stefan Stellato

Managing Associate
stefan.stellato@hannessnellman.com

Parties

Sampo plc (Buyer), Topdanmark A/S (Target)

Transaction

Sampo plc’s mandatory public cash offer for all outstanding shares in Topdanmark A/S

Deal Value

Value not public

Role

Counsel to Sampo plc

Sonja Siggberg

Sonja Siggberg

Partner
sonja.siggberg@hannessnellman.com

Parties

Acorda Therapeutics (Bidder), Biotie Therapies (Target)

Transaction

Acorda Therapeutics' public tender offer of the shares and other securities in Biotie Therapies

Deal Value

USD 363 million

Role

Counsel to Biotie Therapies Corp.

Mikko Heinonen

Mikko Heinonen

Partner
mikko.heinonen@hannessnellman.com
Klaus Ilmonen

Klaus Ilmonen

Partner, Doctor of Laws
klaus.ilmonen@hannessnellman.com
Elina Toivakainen

Elina Toivakainen

Counsel
elina.toivakainen@hannessnellman.com
Heikki Vesikansa

Heikki Vesikansa

Partner
heikki.vesikansa@hannessnellman.com
Anna-Maria Tamminen

Anna-Maria Tamminen

Partner
anna-maria.tamminen@hannessnellman.com
Sonja Siggberg

Sonja Siggberg

Partner
sonja.siggberg@hannessnellman.com

Parties

Faron Pharmaceuticals Ltd

Transaction

Faron Pharmaceuticals Ltd's IPO and listing on the AIM market of the London Stock Exchange as well as the preceding fundraising of approx. GBP 10 million

Deal Value

Approx. GBP 10 million

Role

Counsel to Faron Pharmaceuticals Ltd

Sonja Siggberg

Sonja Siggberg

Partner
sonja.siggberg@hannessnellman.com
Heikki Vesikansa

Heikki Vesikansa

Partner
heikki.vesikansa@hannessnellman.com
Anniina Järvinen

Anniina Järvinen

Partner
anniina.jarvinen@hannessnellman.com

Parties

Biotie Therapies Corp.

Transaction

Public offering and listing of Biotie Therapies Corp.’s shares on the NASDAQ Global Select Market New York

Deal Value

Approx. EUR 83 million

Role

Counsel to Biotie Therapies Corp.

Sonja Siggberg

Sonja Siggberg

Partner
sonja.siggberg@hannessnellman.com
Mikko Heinonen

Mikko Heinonen

Partner
mikko.heinonen@hannessnellman.com
Antti Kuha

Antti Kuha

Partner
antti.kuha@hannessnellman.com

Parties

Asiakastieto Group Plc

Transaction

Asiakastieto Group Plc’s IPO and listing on the Helsinki Stock Exchange

Deal Value

Approx. EUR 170 million

Role

Counsel to Asiakastieto Group Plc

Klaus Ilmonen

Klaus Ilmonen

Partner, Doctor of Laws
klaus.ilmonen@hannessnellman.com
Sonja Siggberg

Sonja Siggberg

Partner
sonja.siggberg@hannessnellman.com
Heikki Vesikansa

Heikki Vesikansa

Partner
heikki.vesikansa@hannessnellman.com
Anniina Järvinen

Anniina Järvinen

Partner
anniina.jarvinen@hannessnellman.com

Rankings

  • Recognised as Highly Regarded and ranked among Women Leaders in Capital Markets and M&A, IFLR1000, 2024
  • "Sonja Siggberg is very responsive and has a holistic view of matters. She is one of the few generalists in the field who can take multiples aspects from different areas of law into account. The partner in charge is always on top of things and knows what the team is working.", Capital Markets, Legal 500, 2024
  • "She has a lot of experience and her work is of excellent quality.", Capital Markets, Chambers Global 2023
  • '"She is technically good," remark interviewees.', Capital Markets, Chambers Global 2022
  • Ranked as a Highly regarded lawyer in Capital Markets and M&A in the 2021 edition of IFLR1000
  • 'Sonja Siggberg "is very proactive, hands-on and always makes me feel like I receive very practical advice which allows me to move forward," says a client. She is well known for her ECM practice, being particularly active in listings.', Capital Markets, Chambers Global and Chambers Europe, 2021
  • Ranked in Capital Markets in Chambers Europe 2020
  • 'One client highlights her technical expertise in the capital markets area.', Chambers Europe, 2019
  • 'Sources say that she is "a skilled capital markets lawyer," adding: "She is proactive and has a good, client-friendly approach."', Chambers Europe, 2018
  • Ranked in Capital Markets in the 2017 edition of Legal 500
  • Ranked as an "outstanding up and comer" in the 2017 edition (Finland: Capital Markets) of Chambers Europe
  • Described as "a very dedicated and ambitious lawyer with a deep knowledge of company law." Sources also say that she is "a good listener.", Chambers Europe, 2017
  • Ranked among the Rising stars in the 2017-2020 editions (Finland: M&A) of IFLR1000

Memberships and Positions of Trust

  • Member of the Finnish Bar Association, 2005

Education and Professional Background

  • Partner, Hannes Snellman, 2014 -
  • Managing Associate, Hannes Snellman, 2012 – 2013
  • Senior Associate, Hannes Snellman, 2005 – 2011
  • Visiting lawyer, Mannheimer Swartling, Berlin, 2003
  • Associate, Hannes Snellman, 2001 – 2005
  • Master of Laws, University of Helsinki, 2001