Art Market Partners is a network of independent art lawyers supporting clients internationally. Advisory contracts are concluded with individual advisers, not with Art Market Partners. Art Market Partners is not a law firm nor a partnership or an incorporated entity.

You can find more information about the members of the network below.

Cathy Kaplan

Cathy represents collectors, artists, galleries, corporations and museums in a wide range of art-related transactions. Cathy has also represented banks and funds on art financing transactions.

Cathy is actively involved in the arts community, serving on several boards and committees. She is the Chair of the Board of Trustees of The Aperture Foundation and on the Photography Committee of the Whitney Museum. Cathy is Chair of the Board of Visitors of Columbia Law School, where she is an adjunct professor and teaches seminars on Law and Finance and Law and Finance of the Art Market. Cathy serves on the Governing Board of the Yale Art Gallery and is Chair of the Nominating Committee of the Board. Cathy also serves on the Board of the Bronx Council on the Arts. For eight years, Cathy served on the Board of Directors of Her Justice (which provides legal services to victims of domestic abuse), and she now chairs its annual Photography Auction and serves on its Senior Advisory Board.

Cathy is a retired partner of Sidley Austin LLP. While at Sidley, Cathy focused her practice on a broad range of structured finance transactions within Global Finance. She worked on structured notes, structured insurance products, CDOs, CLOs, cross-border transactions, asset- and mortgage-backed financings, and art-related financings. Cathy served on the Executive Committee and co-headed Sidley’s Global Finance group for 14 years, and she continues to help curate the art collection of Sidley's New York office. 

In 2022, Cathy was honored by the New York Law Journal with the Lifetime Achievement Award in recognition of her accomplishments and impact on the legal community and the practice of law over the course of her career. In 2021, Cathy led a Sidley team that handled a $1 billion refinancing of a loan secured by a major auction house’s art loan receivables, a deal that was named “Structured Finance and Securitization Deal of the Year” at the IFLR Americas Awards.

Cathy is admitted to the New York Bar.


Columbia Law School
Yale University

Pierre Valentin

Pierre has spent the last 30 years advising private collectors, art businesses and public collections on the law.  He was in-house counsel to Sotheby’s prior to becoming a partner of Withers LLP and for the last 10 years, a partner of Constantine Cannon LLP.  Pierre now runs his own art law practice.  He is a consultant at Fieldfisher LLP and a member of Art Market Partners.

Pierre’s clients include art collectors, art galleries, art dealers, auction houses, artists, museums, private banks, family offices and insurance companies. About half of his clients are based in the UK and the rest of Europe, a quarter in the USA and the rest in the Middle East and Asia. 

Pierre is praised by commentators as “one of the best exponents of art law in the business.” “A veritable giant in the field, he introduced art law to the firm, and now oversees a team looking after art collectors, artists and galleries, museums and foundations.”, says UK Spear’s 500, the annual publication that recognises the top private client advisers, wealth managers, lawyers and service providers for HNW individuals.

Pierre has represented clients in the High Court and the Court of Appeal in matters of ownership, valuation of art, fraud, authenticity, Nazi restitutions, and foreign nation recoveries.  A qualified mediator, he supports clients through the mediation process and has represented clients in LCIA arbitrations.

He structures, negotiates and documents the sale and purchase of blue-chip art and collectibles. He has a wealth of experience in handling all aspects of complex international transactions. He advises art market professionals and businesses on a wide range of regulatory issues including import & export controls, anti-money laundering, art finance and consumer protection.

Pierre has been highly recommended as an expert on heritage property by Legal Experts year-on-year since 2008.

He is regularly called upon to advise on intellectual property rights, with a particular emphasis on copyright and the resale right. For over 10 years, he was a trustee of the Artist’s Collecting Society, one of the two societies collecting copyright and the resale right on behalf of artists in the UK. He co-founded ARTISTATE, a project aimed at supporting artists and artist’s families in planning artistic legacies. 

Pierre was a trustee then chair of World Monuments Fund Britain. He founded PAIAM, the association of Professional Advisors to the International Art Market and more recently, he founded ICRA, the International Catalogue Raisonné Association.

He is a founding member of Restitution Partners, a project aimed at supporting private and public collections in matters of restitution of cultural property.  He sits on the advisory board of the Court of Arbitration for Art in The Hague. 

Pierre is admitted as Solicitor in England and Wales and Avocat at the Barreau de Bruxelles.


The London School of Economics and Political Science (LSE)

Philipp Nuernberger

Philipp advises artists, collectors, galleries, dealers, art finance providers and other art market players on strategic and legal questions pertaining to their practice and business, including on the realization of artistic projects, art and art finance transactions and other commercial arrangements, corporate structure, M&A transactions, and art market specific compliance matters.

Based on years of experience as legal generalist both at major international law firms and in-house, Philipp also provides general counsel services to small and medium sized businesses in the art market and other creative industries. You can find more information at

Philipp has experience on the board of startups and not for profit cultural institutions in the U.S., U.K. and Germany. He currently serves as a member of the board of TIAMSA – The International Art Market Studies Association. Philipp has co-organized conferences on art law at the National Gallery in London and Christie’s in New York and London, amongst others, and has spoken as a guest lecturer at universities in the U.S., France, Germany and Poland. He is published on a range of art market related topics.

Philipp's international background and work experience in the U.S., U.K., Germany, France and Spain enable him to navigate cultural differences with ease and to provide advice and negotiate in English, German and French.

Philipp is admitted to the New York Bar.


New York University School of Law
Humboldt University Berlin
University Paris 1 Panthéon-Sorbonne
Heidelberg University

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Art Market Partners is not a law firm, nor a legal partnership or incorporated entity. Instead, it is an informal network of independent legal advisers. Any advisory contract is concluded between client and individual adviser.

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