John McArthur established the Law Office of John Burritt McArthur in 2008 in order to combine a growing practice as an arbitrator with his active trial practice. McArthur has been involved as a lawyer in some of the largest commercial disputes of the last 28 years. His earliest work concerned an antitrust case over tennis ball manufacturing and an antitrust lawsuit between Northrop Corporation and McDonnell-Douglas over the F-18 fighter plane. In the 1980s, as a partner in Houston's Susman Godfrey LLP, he played a major role in natural gas take-or-pay litigation. In the 1990s, he represented one of Alaska's native corporations in a large dispute with the Department of the Interior, advised major oil companies on Alaskan matters, and handled other energy cases while in a Ph.D. program in public policy at the University of California at Berkeley. From 1999 to 2008, as a partner in what ultimately became San Francisco's Hosie McArthur LLP, he devoted the bulk of his time to a series of oil posted-price and natural gas royalty cases, including cases for the States of Alaska and Louisiana. McArthur continues to provide trial representation for states and other clients in royalty and tax litigation, and increasingly sits as an arbitrator in large commercial disputes.

McArthur has been a trial lawyer in some of the largest jury trials of the last few decades. Early in his career, he was one of the lawyers who tried the first take-or-pay case to go to trial on a repudiation theory. The jury awarded a $563 million verdict against El Paso Natural Gas Company in one of the top 10 jury verdicts in 1988. Soon after counsel including McArthur argued the appeal in a Houston court of appeals, El Paso settled by paying $302 in cash and returning mineral interests later appraised at $135 million.

McArthur also played a major role in Chevron against the State of Louisiana, which began as a defense case. It was one of the few oil posted-price cases to go to trial. After the court realigned the State as the true plaintiff, the jury awarded $111 million against Chevron in one of the top 15 verdicts in 2004. For a representative list of past cases, see Experience.

McArthur's has handled cases in state and federal courts around the country. His clients come from the plaintiff and defense sides of the docket and have ranged from some of the country's largest corporations to Alaskan native corporations, States, individuals, and small businesses. Among his plaintiff clients have been the states of Hawaii, Alaska, Louisiana, and Mississippi, Aetna Life Insurance, the second largest producer of natural gas in Texas, and one of the largest interstate gas marketers into the California market. Among his defense clients have been Aetna, Sonat Offshore, British Petroleum, and BASF.

In terms of subject matter, McArthur's cases have run the gamut from antitrust disputes to securities and intellectual property lawsuits, from racketeering and qui tam claims to contract and tort disputes and many varieties of energy cases.

McArthur has a broader perspective on complex trial work because he has also served as an expert and as an arbitrator, and has advanced academic training in complex economic topics. Among his expert testimony is testimony cited with approval by the Arkansas Supreme Court in Seeco v. Hales, 22 S.W.3d 157 (Ark. 2003). Holding advanced degrees in economics, public administration, and public policy, McArthur has graduate-level training in the economic and financial concepts used in many complex commercial disputes. He has written over 35 articles in law reviews and bar publications, including articles on arbitration, judicial management, many energy issues, and antitrust. For his major publications, see Publications.

As an arbitrator, McArthur is listed as a neutral for the Commercial Case, Oil and Gas, and National Energy Panels of the American Arbitration Association; as a Distinguished Neutral for the California and Energy, Oil and Gas Panels of the International Institute for Conflict Prevention and Resolution (CPR); and by the international arbitration centers in Singapore, Hong Kong, Dubai, and Kuala Lumpur. He is a member of the International Bar Association, the London Court of International Arbitration, the American Society for International Law, and a Sponsoring Member of the Institute for Energy Law and the Institute for Transnational Arbitration. His approach to arbitration is described in Arbitration.

McArthur has been acknowledged for his experience by his peers. In 2007, he was elected a Fellow of the Litigation Counsel of America, a fellowship composed of top American lawyers. He has long held an "av" rating from Martindale-Hubbell.

McArthur has devoted an increasing share of his time to serving as an arbitrator in recent years in the belief that alternative dispute mechanisms are gradually supplanting the court system because the courts have grown so crowded. With a long-standing interest in problems of case management, McArthur has published articles on this topic in law journals and Judicature, the magazine for the nation's judges.