James P. O'Sullivan

James P. O'Sullivan



Legal Assistant:

Maria Malagon

JIM O'SULLIVAN represents closely-held businesses, including law firms and other service professionals. Serving as general counsel and primary contact for businesses and their owners, Jim focuses on the ongoing legal needs of these clients, as well as strategic planning for growth and ownership succession opportunities. Jim leverages his considerable planning, negotiation and contract drafting experience to counsel clients through key events such as business formation, joint ventures, mergers and acquisitions, and other agreements among business owners.

Business divorces, related fiduciary duties and other disputes among businesses are also a substantial part of Jim's practice. He has significant experience in resolving disputes among businesses and their owners, often serving in a consulting role to litigation attorneys and their clients in mediation and other forms of dispute resolution.

Jim frequently acts as counsel and as consulting counsel to other attorneys in transactions, including providing local counsel assistance to non-Arizona attorneys and their clients. Additionally, he has considerable experience as an expert witness in business law matters. Jim has been recognized by his peers with an AV rating for his legal abilities and ethics, the highest rating awarded by Martindale-Hubbell, an international attorney rating service. Jim has lectured and published extensively on business law and related ethics issues. He was one of the drafters of the revised Arizona corporate statutes, having served during the drafting process as State Bar of Arizona liaison to the Arizona Corporation Commission, and is a co-author of Arizona Corporate Practice, published by Thomson West.

Jim's community service centers on his interest in interactive education, whether as an in-classroom Junior Achievement volunteer introducing middle school students to his entrepreneur clients or interacting as a presenter with the business community and other professionals.

Arizona (1983)
U.S. District Court, District of Arizona
U.S. Tax Court


  • Legal Issues in Buying a Company
  • A Thorough Analysis of the Unique Issues of the Limited Liability Company
  • When Business Partners Part Company
  • Done and Done-Er - The Lawyer's Odyssey to Closing...and Beyond!
  • Resolving the Business Dispute
  • Sales and Mergers of Law Firms
  • Closing a Law Practice
  • Mergers and Acquisitions of CPA Firms
  • The Ties that Bind?
  • Who is Your Client? Commentary on a New Ethics Opinion on Representing a "To-Be-Formed Company."
  • Arizona Practice Guide, a two-volume treatise published by Thomson West since 1995.
  • Revocation of Corporate Charter Raises Tax Questions," 22 Taxation for Lawyers 76, 1993, 51 Taxation for Accountants 92, 1993;
  • "Articles of Incorporation Revoked-NO BIG DEAL?," 29 Arizona Attorney 18, 1993; "COBRA-Recent Developments Shed Light on Gross Misconduct Sanctions," 28 Arizona Attorney 15, 1992;
  • "COBRA: A New Law Requires Immediate Attention to Group Health Plans," 22 Arizona Bar Journal 8, 1986, reported in Westlaw.


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