Derek E. Diaz


Derek E. Diaz serves as chair of Hahn Loeser’s Appeals & Critical Motions group. He brings a wealth of trial and appellate experience to complex commercial matters, including class actions and employee raiding cases. As an Ohio State Bar Association board certified specialist in appellate law, Derek’s clients include Fidelity National Financial Inc., ExxonMobil Corp., Nucor Corp. and Century 21 Real Estate LLC.

Derek offers additional professional insights a one of the founders of the The Class-Action & Compliance Sentinel blog, which keeps real estate professionals apprised of new developments regarding class actions and compliance matters in that industry.  Derek also is a member of the firm’s Real Estate Industry Services group. He is a Life Member of the 6th Circuit Judicial Conference.

Professional History

  • Ohio State Bar Association Board Certified Specialist in Appellate Law
  • Partner, Hahn Loeser & Parks LLP, 2009-present; Associate, 2004-08
  • Law Clerk to the Honorable Arthur I. Harris, United States Bankruptcy Court for the Northern District of Ohio, 2002-04
  • Judge Advocate; United States Marine Corps, 1998-2002
  • inVentiv Health Communications, Inc. v. Rodden, Fifth Dist. Delaware No. 17CAE09 0066, 2018-Ohio-945. Successfully obtained partial reversal of adverse judgment in case involving enforcement of non-competition agreement against North Carolina resident.
  • Atlas Noble, LLC v. Krizman Enters., 692 F. App’x 256 (6th Cir. 2017). Successfully obtained appellate reversal of $2.4 million judgment against oil-and-gas company, which had resulted from failed sale of mineral interests.
  • Safi v. Central Parking System of Ohio, Inc., 45 N.E.3d 249 (Ohio Ct. App. 2015). Obtained appellate reversal of order granting plaintiff’s motion for class certification in case involving allegedly improper practices for towing automobiles.
  • Carter v. Welles-Bowen, Inc., 736 F.3d 722 (6th Cir. 2013). Defeated class certification and obtained summary judgment in RESPA case of national precedent, which invalidated a long-standing HUD policy statement relating to affiliated-business arrangements.
  • Defeated class certification in two suits alleging that Fidelity National Title Insurance Company and Chicago Title Insurance Company had overcharged for title insurance policies in five different states.
  • Hazewood v. Found. Fin. Group, LLC, 551 F.3d 1223 (11th Cir. 2008). Successfully defended Ticor Title Insurance Company in a national class action seeking damages for alleged title insurance overcharges.
  • Represented ExxonMobil Corporation in multi-district litigation involving “MTBE,” a fuel additive, for a mandamus action and a collateral‑order appeal from the district court’s plan to conduct bellwether trials.
  • Tharo Sys., Inc. v. cab Produkttechnik GmbH & Co. KG, 196 Fed. Appx. 366 (6th Cir. 2006). Obtained a successful appellate defense, following jury trial, of €1.7 million judgment in favor of an Ohio software development company against a German company that breached a partnership agreement.
  • Successfully obtained injunctive relief on behalf of Ticor Title Insurance Company against former agent in complex, multi-state litigation for former agent’s wrongfully continuing to hold itself out as a licensed agent after termination.
  • Represents Ticor Title Insurance Company in multiple lawsuits, state administrative proceedings, and regulatory investigations that involve coverage disputes that were caused by the misconduct or fraud of agents and former agents.



Ohio State University, J.D., May 1998

Honors & Activities: Ohio State Law Journal, Staff Editor, 1997-98; Cali Award for Pretrial Litigation, 1998; Judge Joseph M. Harter Memorial Award for Trial Practice, 1997


John Carroll University, B.A., Political Science, magna cum laude, 1995

Community Involvement

National Multiple Sclerosis Society, Ohio Buckeye Chapter, Volunteer

Awards & Distinctions

Ohio Super Lawyers®, Business Litigation, 2014-18


Rising Star, Ohio Super Lawyers®, 2010-13


Distinguished Service Award, Standing Committee on Legal Assistance for Military Personnel, American Bar Association, 2001


Achievement Medal, U.S. Navy & Marine Corps, June 2000 (For service on Aviano Trial Team)


Award for Trial Advocacy, New York Bar Association, December 1999

Bar Admissions

State of Ohio, 1998


U.S. Supreme Court, U. S. Courts of Appeals for the Fifth, Sixth, Eighth and Eleventh Circuits; U.S. District Courts for the Northern and Southern Districts of Ohio

Memberships & Affiliations

American Bar Association, Member


American Land Title Association, Associate Member; Best Practices Committee Member, 2016-present; State Advocacy Committee, Member, 2016-present


Cleveland Law Library Association, Board of Directors


Cleveland Metropolitan Bar Association, Bench-Bar Committee, Member


Federal Bar Association, Northern District of The Ohio Chapter, Board of Directors; CLE Committee, Chairperson


Real Estate Services Providers Council, Inc., Associate Member; Program & Education Committee, Member, 2016-present