Gregor has a strong disputes and transactional practice in art and cultural heritage law. He acts for a wide range of private clients, private and institutional art collectors, art dealers, commercial art galleries, fine art agents, funding organisations and various private and public institutions. Gregor advises on the contractual aspects of commissioning, buying or selling art, whether through commissioning agreements with artists, agency or gallery agreements, private treaty sales or consignment by auction, including advice on pre-acquisition due diligence and the application of artists' resale right. In relation to the ownership and management of art collections, he has consulted on matters such as the loan of artworks for exhibition, the use of artworks as collateral for financial transactions, and the restoration and insurance of artworks. When disputes arise, Gregor represents clients in relation to contract and title disputes, historical restitution claims, on questions of misattribution or authenticity of artworks and illegally excavated and/or exported artefacts.
Gregor qualified as a German Rechtsanwalt in 1995 and as an English solicitor in 1996. Following a career at two leading international City of London law firms and at a US law firm, Gregor founded and led the boutique firm of Klein Solicitors. Gregor joined Hunters as a partner in the art, dispute resolution and business services departments upon the merger of the two firms in February 2014.
Gregor is a founding member and chairs the board of the Professional Advisers to the International Art Market (PAIAM), a member of the Institute of Art and Law (IAL), Art Law Foundation, Lawyers' Committee for Cultural Heritage Preservation, Institut für Kunst und Recht, the Arts Club and the Fondation Maeght.