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Sonja Otenhajmer


CMS Reich-Rohrwig Hainz
Rechtsanwälte GmbH
Gauermanngasse 2
1010 Vienna
Languages German, English, Serbian, Bosnian, Croatian, Italian, Spanish

Sonja Otenhajmer is a Litigation and Arbitration as well as a corporate and commercial attorney-at-law. She focuses on international arbitration.

Otenhajmer completed her legal studies at the universities of Vienna, Bologna and Belgrade. During her studies at the University of Vienna, which she completed with distinction, she participated in the Willem C. Vis International Commercial Arbitration Moot. She gained varied professional experience as a university assistant at the Institute for Civil Procedure Law at the University of Vienna and in renowned international commercial law firms in Vienna and Madrid. Otenhajmer joined CMS in Vienna as an associate in 2016.

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‘We work with Daniela Karollus-Bruner and Sonja Otenhajmer, their work is fast and diligent.’

The Legal 500 EMEA, 2024

Relevant experience

  • 2012–2014  University assistant at the University of Vienna’s Department of Civil Procedure
  • 2010–2015  Practical experience at renowned law firms (Vienna, Madrid) 
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Memberships & Roles

  • Young Austrian Arbitration Practitioners (YAAP)
  • Austrian Bar Association
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  • Anmerkung zur Entscheidung des OGH 4 Ob 71/14s, EvBl 2015/2.
  • Internationale Wirtschaftsmediation im studentischen Wettbewerb, JAP 2013/2014
  • Anmerkung zur Entscheidung des OGH 8 ObS 14/12k, ÖJZ 12/2013, 550.
  • Sind Leasingentgelte für Superädifikate Sondermassekosten?, ZIK 4/2010, 126.
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Lectures list

  • Vortrag über Mediation und Verhandlungstechniken, Aarhus Universitet, Dänemark, 2014
  • Universitätslektorin für Zivilverfahrensrecht, Universität Wien (2013–2014)
  • ICC International Commercial Mediation Competition, Paris, Coachin des Wiener Teams (2013, 2014)
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  • 2015 – Mag.a iur., Law, University of Union, Belgrade
  • 2014/15 – Court practice in the district of the Vienna Higher Regional Court
  • 2012 – Mag.a iur., Law, University of Vienna
  • 2011 – Erasmus, Law, University of Bologna
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CMS promotes 54 to global partnership
International law firm CMS is pleased to announce the promotion of 54 new partners. The new partners are based in 24 cities in 17 countries around the world, reflecting the firm's international strength and depth. Women account for 41% of all global promotions. Pierre-Sé­bas­tien Thill, CMS Chairman, comments: “Con­grat­u­la­tions to our new partners. In addition to their legal expertise and cutting-edge sector knowledge, they demonstrate deep curiosity about future business challenges and opportunities as well as help foster a culture of innovation, inclusivity and sustainability within our organisation. All these are traits needed to help our clients, and CMS, prepare for the world of to­mor­row.”CM­S's annual partner promotions take into account promotions that take effect between 2 May 2023 and 1 May 2024. The full list of new Partners can be found below:
CMS Partner Sonja Otenhajmer joined the YAAP Advisory Board
Sonja Oten­hajmer, Dis­pute Resolution Expert and Partner at CMS Austria, has been appointed as member of the Young Austrian Arbitration Practitioners (YAAP) Advisory Board.
Rohlik – parent company of Gurkerl.at – receives 220 million euros of Series...
The new capital will be used both to finance the online grocer’s continued expansion in Germany, Italy, Spain and Romania and to drive forward technical innovation. Founded in 2014, online grocer Rohlik, which revolutionised grocery in Austria with gurkerl. at, is one of the fastest growing retailers in the Czech Republic and the entire CEE region. Promising delivery just 90 minutes after an order is placed, the company already supplies more than one million customers with more than 17,000 products. Rohlik now not only offers its delivery service in Vienna (gurkerl. at), but also in Prague (rohlik. cz), Budapest (kifli. hu), Munich and Frankfurt (knuspr. de). Soon the service plans to launch in Hamburg, Milan (sezamo. it), Bucharest (sezamo. ro) and Madrid (sezamo. es). The fresh capital will be used to finance continuing expansion and drive technical innovations. Alexander Rakosi, Partner in the CMS Vienna Corporate Transactions Team, is delighted with the deal: “Such a large cross-border transaction always raises a number of complex legal and organisational issues that require sound legal expertise and a well-coordinated transaction team. Our international network enables us to provide our clients with comprehensive advice and access to seasoned experts in all coun­tries.”Man­aging Partner of CMS in Prague and Bratislava, Helen Rodwell, is also pleased about the successful closing: “We are proud to have been able to accompany this new financing round. Rohlik’s unique offering and first-class service make it an attractive growth candidate for investors cautious due to the current economic and geopolitical climate. As a leading international law firm – with a significant presence in CEE and many other European countries – CMS is ideally placed to provide legal support for this kind of cross-border trans­ac­tion.”The Austrian CMS legal team in Vienna included Alexander Rakosi and Florian Mayer (Corporate Law/M&A), Anna Hiegelsperger (Corporate Law/M&A), Jens Winter (Employment & Pensions), Sonja Otenhajmer (Dispute Resolution), Mariella Kapoun (Real Estate & Construction) and Maximilian Uidl (Real Estate & Construction). The international CMS legal team was led by experienced CMS partner Helen Rodwell (CMS Czech Republic) and consisted of David Cranfield (CMS Romania), Štěpán Havránek and Tristan O'Connor (CMS Czech Republic); and Moritz Kopka (CMS UK). Also advising were Florian Kamienke and Oliver Thurn (CMS Germany); Miklos Boros (CMS Hungary); José Luis Rodriguez and Carlos Peña (CMS Spain); Cristina Ciomos and Rodica Manea (CMS Romania); and Alessandra Cuni, Sara Tammarazio and Daniela Murer (CMS Italy). 
Sonja Otenhajmer strengthens the CMS team as attorney-at-law specialised...
Sonja Otenhajmer continues to support the Dispute Resolution Team at CMS in Vienna as a registered attorney-at-law. Her focus remains on international arbitration. Sonja Otenhajmer (31) has supported...