Matthias advises clients in complex transactions, specifically joint ventures and international M&A projects which require bespoke structures. His experience also covers corporate law advice and arbitration. Working as part of a team with his clients, Matthias' practice focuses on developing conclusive solutions to achieve their economic goals, analyzing different structural options and weighing up the pros and cons beyond the legal issues.

In private M&A Matthias has, for example, advised Bayer AG on the sale and carve-out of the Diabetes Care Business (2014-2016), GEA Group AG on the carve-out and sale of its Heat Exchanger Segment (2013-2014), RWE AG on the sale of the Upstream Business of Dea (2013-2015), and Intel on its acquisition and carve-out of the Wireless Business of Infinion (2010).

He is also active in public M&A, most recently the defence of K+S AG when Potash Corp. launched a takeover approach (2015), the public takeover of Impreglon by Aalberts Industries with the subsequent merger squeeze out (2015), and the takeover of Tognum by Rolls-Royce and Daimler followed by a takeover squeeze out and the full acquisition by Rolls-Royce, including structural integration. Earlier prominent transactions in which he advised include the white knight Vivendi in the takeover of Mannesmann by Vodafone (2000) and the merger of Hoechst and Rhône-Poulenc to become Aventis (1999).

Matthias regularly advises on joint ventures, either in operative businesses or for R&D purposes, and in all stages starting from the formation and ongoing cooperation up to termination. Often, these joint ventures play a structural role in transactions, such as the cooperation between RWE and numerous infrastructure investors on the backbone grid Amprion (2010-2011), between Rolls-Royce and Daimler regarding the takeover of Tognum (2010), or the downstream business combination of Shell and Dea (2000-2002).