Roger Thomi

Maurus Winzap is a partner and heads the Tax Team. Maurus' practice covers all areas of domestic and international corporate taxation. He acts for a broad range of corporate and financial clients, and has developed significant expertise in planning and advising on M&A and private equity transactions, structured financings, corporate restructurings, relocations, capital market transactions, collective investment schemes and management incentive programs. Furthermore, he focuses on advice t...

Florian Gunz Niedermann is a top attorney recognized by Best Lawyers in the practice area(s) of Mergers and Acquisitions Law. Florian, who practices law in Zürich, Switzerland, has been recognized since 2026. This recognition is based on an exhaustive peer-review survey, reflecting the high esteem in which Florian is held by other top lawyers in the same geographic and legal practice area.

Partner Dr Patrick Sommer is Co-Head of the CMS Competition & EU Group. In this position, he jointly leads an international team of more than 170 competition lawyers. Patrick Sommer focuses on competition law, corporate law and M&A. Patrick Sommer has graduated from the University of St.Gallen in 1987 and was admitted to the bar in 1989. He has written his doctoral thesis on the relationship of Switzerland to the European Union and completed postgraduate studies at the Collège ...

Monique Sturny is a top attorney recognized by Best Lawyers in the practice area(s) of Antitrust/Competition Law and Public Law. Monique, who practices law in Zürich, Switzerland, has been recognized since 2024. This recognition is based on an exhaustive peer-review survey, reflecting the high esteem in which Monique is held by other top lawyers in the same geographic and legal practice area.

Partner Mark Cagienard specialises in tax law, covering individual and corporate taxation both on a domestic and international level with a particular focus on corporate finance, M&A and VAT. Mark Cagienard assists clients frequently in obtaining tax rulings and represents them in front of courts and tax authorities. Mark Cagienard graduated from the University of Zurich in 2006 (magna cum laude) and was admitted to the bar in 2008. In 2012 he qualified as a Swiss Certified Tax Expert. In...

Hans-Jakob Diem is a corporate Partner at Lenz & Staehelin. He heads the firm's Corporate and M&A practice group and is the co-head of the Capital Markets practice group in Zurich. He has extensive experience in representing clients in a variety of corporate transactions, concentrating on mergers and acquisitions, capital market transactions, bank financings and corporate governance matters. Hans-Jakob Diem is regarded as a leading corporate practitioner in Switzerland and is regularl...

Martin Busenhart is a partner in the Tax Team. He advises on national and international tax matters and is specialised in domestic and international structuring of capital market transactions, acquisitions and divestments and tax-optimized structuring for relocations of entrepreneurs, partnerships and corporate groups. Martin Busenhart was educated at Zurich University (lic. iur. 1988) and graduated as Certified Tax Expert (1994). He has working experience as tax expert and tax partner with a...

Daniel Staffelbach is a partner in the Corporate & Commercial Team of Walder Wyss. He counsels Swiss and international clients in all sectors of health care & life sciences and in the insurance industry. His main areas of practice include company and contract law, public law and employment law. He advises his clients and also represents them in litigation. Born in 1966, Daniel Staffelbach studied law at the University of Berne (attorney 1993). He worked at the Administrative Law Panel...

Michael Cartier represents parties in international arbitrations under all major institutional rules and in ad-hoc proceedings, before state courts and in enforcement and legal assistance matters. He is listed as an expert for arbitration in Who's Who Legal 2016, 2017, 2018, 2019, 2020 and 2021. He also acts as arbitrator and is listed on the panel of arbitrators of the ICC National Committee (Switzerland) and of the Korean Commercial Arbitration Board. The focus of his work is on constructio...

Roger Staub is a Partner in the Information Technology, Intellectual Property and Competition Team. He represents national and international companies from various industries, such as luxury goods, pharmaceuticals, food, financial services, fashion, medical devices and media. He specialises in litigating complex cases before state courts and arbitration tribunals. In addition, he advises clients in negotiating IP and technology-related contracts and in developing IP strategies. He also works ...