Professor Liegl studied law at LMU Munich. After completing his studies he worked as a lawyer in New York, Chicago, Minneapolis/St. Paul (USA) and Paris. In 2006 Professor Liegl was appointed honorary professor at TUM. Professor Liegl is a partner in international law firm Noerr LLP. He advises strategic and private equity investors on domestic and cross-border M&A transactions and corporate restructuring. He also advises on the purchase, sale and structuring of entrepreneurial investments. In the field of media, sport and sponsoring he has provided advisory services for major sports events including the 2008 Olympic Games in Peking, the 2012 Olympic Games in London, the 2016 Olympic Games in Rio, the 2010 Winter Olympics in Vancouver, the 2014 Winter Olympics in Sochi, the 2012 Youth Olympics, the FIFA World Cup (2002, 2006, 2010, 2014, 2018), the Bundesliga, Formula 1, tennis, boxing and other sports events.
- Judge at the German Court of Arbitration for Sport at the German Institution of Arbitration (DIS)
- Director, Formula One Management Ltd. and Formula One Administration Ltd., London
- Sports director, KirchMedia, Munich
- Chair of the International Sports Law Practice Group of Lex Mundi, the world's leading association of independent law firms
- Honorary consul of the principality of Monaco, Munich (since 1993)