Marianne I. Sieger

Attorney at Law

Marianne I. Sieger

Phone +41 44 215 41 41
Fax. +41 44 215 41 49

Law practice since 1997
Languages: German, English and French

Preferred areas of practice

Social and private insurance law, contract law, family and inheritance law, matrimonial and cohabitation law

Further professional activities

Independant proxy at Bystronic AG (formerly Conzzeta AG until April 2021, since 2014), Plazza AG (since 2016), Flughafen Zürich AG (since 2017).


  • Swiss Bar Association (SAV)
  • Zurich Bar Association (ZAV)

Professional background

  • Partner at Bretschger Leuch Attorneys at Law, 1.10.2009
  • Partner at Giger & Partner, 2005 renamed Leuch & Sieger, 1997–2009
  • Legal Clerk at the Social Insurance Court of the Canton of Zurich, 1996–1998
  • Legal Clerk in a medium-sized law firm in Zurich focused on commercial law, 1994–1995
  • Legal Clerk at the District Court of Pfäffikon, 1992–1993


  • Admitted to the Zurich Bar, 1995
  • Licentiate from the Faculty of Law and Political Science, University of Zurich, 1992

Continuous further professional education