Twice each year from 2004-2012,  Greg assisted mediation pioneers Professor Frank Sander and Washington, D.C. mediators Linda Singer and Michael Lewis in teaching the prestigious "Mediation Workshop" at the Harvard Negotiation Institute. Greg is a Past Chair of the California State Bar's Standing Committee on Alternative Dispute Resolution, a Distinguished Fellow of the International Academy of Mediators, a Fellow of the Chartered Institute of Arbitrators, and a member of the CPR Panel of Distinguished Neutrals, the California and National Academies of Distinguished Neutrals, the Arbitration Panels of the International Chamber of Commerce (ICC), the London Court of International Arbitration (LCIA), the Mediation and Arbitration Panels of the World Intellectual Property Organization (WIPO), and a member of the American Arbitration Association Roster of Neutrals (AAA), and a past member of the arbitration panel of Independent Film & Television Alliance (IFTA).

Greg was named as a "Power Mediator" by The Hollywood Reporter in its list of the mediators to whom the entertainment community turns to resolve disputes. He has been recognized annually since 2006 as a SuperLawyer in the fields of ADR, Intellectual Property Litigation and Entertainment and Sports Law.  Based upon the review of his peers, Greg has achieved an AV rating in the Martindale Hubbell Law Directory and has been named a Best Lawyer in Los Angeles for Mediation since 2021 and Arbitration since 2022.

Greg has received mediation and arbitration training through highly respected programs including the Harvard Law School "Mediation Workshop," Pepperdine University School of Law's Straus Institute for Dispute Resolution, Ken Cloke's Center for Dispute Resolution, The Center for Dispute Settlement in Washington, D.C., Dispute Resolution Services, Inc. of the Los Angeles County Bar Association, the International Academy of Mediators, the Section of Dispute Resolution of the American Bar Association, the American Arbitration Association, the Chartered Institute of Arbitrators and the Independent Film and Television Alliance.

In 1979, Greg joined the law firm of Dern, Mason, Swerdlow and Floum, where he practiced for ten years, becoming the Managing Partner of the firm's litigation department. Upon the dissolution of Dern, Mason in 1989, he became a founding member of Del, Rubel, Shaw, Mason & Derin, where he remained until opening his own office in 1997.

Greg is experienced in all phases of litigation, having handled matters before federal and/or state trial or appellate courts in California, Illinois, New York, Pennsylvania, among other jurisdictions, and before the American Arbitration Association, California Labor Commissioner, Screen Actors Guild, American Federation of Television and Radio Artists, the Major League Baseball Players' Association, California Regional Water Quality Control Board, California State Water Resources Control Board, and the National Association of Securities Dealers.

Greg has litigated, mediated and arbitrated matters in diverse substantive areas, including contract, fraud, blockchain, cryptocurrency, entertainment, including talent agency and management and commissions, motion picture, television, music (including licensing and valuation of music rights), computer, social media, apparel, internet and high techology, intellectual property (including copyright, trademark, trade dress, secondary meaning), photography, copyright termination, Lanham Act, Digital Millennium Copyright Act, dilution, deceptive trade practices, licensing, trade secrets, unfair competition, rights of privacy and publicity, defamation (libel and slander), misappropriation, Federal Trade Commission, breach of fiduciary duty, real estate, employment, wage and hour, wrongful termination, corporate and partnership, legal malpractice, class actions, unjust enrichment, business torts, interference with contract and prospective economic advantage and unfair business practices.. He serves as principal outside litigation counsel to a major talent agency, was lead local counsel in Southern California to a Fortune 500 company in connection with a series of product liability matters involving a medical device, and has tried cases as varied as a class action concerning a real estate development, a multi-million dollar construction defect matter, and talent agency disputes.

He is admitted to practice before all state and federal courts in California, the United States Courts of Appeals for the Ninth and Federal Circuits, and the United States Supreme Court.

Greg is a Phi Beta Kappa graduate of the University of California at Berkeley, from which he received an A.B. degree with Highest Honors in 1976. Greg received a J.D. degree from the University of California, Berkeley School of Law in 1979, where he was on the editorial board of the California Law Review.

University of California, Berkeley , A.B., 1976
Graduation with Highest Honors in Political Science
Phi Beta Kappa

University of California, Berkeley School of Law, J.D., 1979
Research and Book Review Editor, California Law Review

Mediation Training:
Harvard Law School, Program of Instruction for Lawyers, Mediation Workshop (30.5 Hour Training Program Led by Professor Frank E.A. Sander, Linda Singer and Michael Lewis) Pepperdine University School of Law, Straus Institute for Dispute Resolution, Mediating the Litigated Case (42 Hour Certificate Program) Center for Dispute Settlement (Washington, D.C.), Advanced Mediation Techniques (18 Hour Program) Dispute Resolution Services, Inc. (Los Angeles County Bar Association), Advanced Mediator Skills Training (15 Hour Certificate Program) American Bar Association, Section of Dispute Resolution/International Academy of Mediators, Advanced Mediation and Advocacy Skills Training (12 Hour Training Program) Center for Dispute Resolution (Kenneth Cloke), Mediation Training (30 hour Training Program) Pepperdine University School of Law, Straus Institute for Dispute Resolution, Advanced Training for United States District Court Settlement Officers: Cross-Cultural Ramifications in Mediations, Overcoming Impasse and Transparency in Mediations, Mediator Influence and Overcoming Barriers, To Caucus or Not to Caucus,  and Helping People Make Effective Decisions in Mediation

Arbitration Training:
American Bar Association, Section of Dispute Resolution, "Arbitration Training Institute" (20 Hour Training Program); American Arbitration Association, "Arbitration Fundamentals and Best Practices (2 Day Training Program); Chartered Institute of Arbitrators (3 Day Training); Independent Film and Television Alliance Panel Training

• Distinguished Fellow, International Academy of Mediators
• Fellow, Chartered Institute of Arbitrators
• Past Chair, Southern California Chapter, North American Branch, Chartered Institute of Arbitrators
• Chair, California State Bar Committee on Alternative Dispute Resolution 2006-2007
• Member, California State Bar Committee on Alternative Dispute Resolution 2003-2007
• Member, American Arbitration Association Roster of Neutrals
• Member, CPR Panel of Distinguished Neutrals (Los Angeles and Entertainment Panels)
• Member, California and National Academies of Distinguished Neutrals
• Member, World Intellectual Property Organization (WIPO) Mediation and Arbitration Panels
• Member, Panel of Neutrals, London Court of International Arbitration
• Past Member, Arbitration Panel, Independent Film & Television Alliance (IFTA)
• Past Settlement Officer, California Court of Appeal, Second Appellate District
• Member, Copyright Society of the United States, Los Angeles Chapter
• Member, Los Angeles Copyright Society
• Member, Los Angeles County Bar Association (Intellectual Property and Entertainment Sections)
• Member, Beverly Hills Bar Association (Entertainment and Dispute Resolution Sections)
• Member, American Bar Association (Litigation and Dispute Resolution Sections)
• Member, Federal Bar Association
• Member, Los Angeles Intellectual Property Association
• Member, Sports Lawyers Association
• Member, Association of Business Trial Lawyers Association