John M. Losinger


Florham Park

T 973-232-0606

John "Jack" Losinger advocates on behalf of businesses and individuals in connection with commercial disputes, with a specific focus on violations of restrictive covenants and the misappropriation of trade secrets and confidential information.  

Jack’s wide range of litigation experience - which includes employment lawsuits arising from claims of discrimination and harassment, contractual and estate disputes, environmental cost recovery actions, tax appeals, and municipal court matters - gives him the ability to quickly adapt and pursue a strategy that is in the best interest of his client.  By making a concerted effort to understand the strengths and weaknesses of his client’s position, he has had success negotiating favorable pre-suit resolutions and, when necessary, litigating in state and federal court and in arbitration.  Jack’s clients have included individuals, small companies and publicly traded corporations.  

Jack also has extensive experience conducting comprehensive investigations of a variety of sensitive matters for institutions of higher education and private sector employers, including allegations of inappropriate conduct in the workplace, ethical violations, conflicts of interest, policy violations, and bullying. 

Jack is regularly appointed by Chancery Division judges in Essex County and Morris County to serve as the court-appointed attorney for alleged incapacitated persons in guardianship matters.

Reported Opinions

Capparelli v. Lopatin, 459 N.J.Super. 584 (App. Div. 2019) (applying the doctrines of frustration of purpose and impossibility to affirm the trial court’s avoidance of a written contract)

Listed In:

  • Best Lawyers® - Commercial Litigation - 2024
  • New Jersey Law Journal - New Leader of the Bar, 2021
  • New Jersey Super Lawyers® - 2023-2024
  • New Jersey Super Lawyers® - Rising Stars - 2015-2021
John M. Losinger
Rated by Super Lawyers

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New Jersey State Bar Association

Programs Co-Chair, ABA Business Torts and Unfair Competition Committee

Judging Panel, Vincent J. Apruzzese High School Mock Trial Competition

  • Represented a technology company in a bench trial relating to a former employee's allegations of breach of contract, wage and hour violations, and retaliation. After nine days of trial, the matter was resolved for a fraction of the plaintiff's pre-trial demand.

  • Represented an employer and successfully thwarted two former employees’ efforts to misappropriate the employer’s confidential information, violate their restrictive covenants, and work for a direct competitor.  After filing a Verified Complaint and Order to Show Cause, and securing temporary restraints, and a preliminary injunction, the matter was resolved to the employer’s satisfaction. 

  • Defended claims that a former employee was owed significant post-employment commissions payments arising from the termination of an Employment Agreement and successfully negotiated a pre-suit resolution of the dispute.

  • Following an evidentiary hearing, obtained a judgment that a written contract was void based on the doctrines of impossibility and frustration of purpose. The judgment was affirmed by the Appellate Division in a reported opinion.

  • Obtained numerous favorable rulings in a multi-day arbitration in which former business partners presented hundreds of disputes arising from the negotiated wind-down of their shared business entities.

  • Successfully negotiated a favorable settlement on behalf of the owner of commercial property in a claim arising from the tenant's breach of a lease agreement, which required the tenant to provide defense and indemnity in connection with a slip and fall accident that occurred at the property.

  • Following a bench trial, obtained a judgment dismissing plaintiff's claims that a contractor breached its construction contract. 

  • Represented employers, both pre-suit and in litigation, in connection with claims for hostile work environment, discrimination, and wrongful termination.

  • Following a bench trial, procured a judgment for money damages in favor of a multinational IT and networking company, on the basis that a customer breached a UCC Finance Lease Agreement.

  • Successfully resolved probate litigation on behalf of the executor of an estate arising from a dispute as to the validity of a handwritten codicil to the decedent’s will.

  • Successfully moved to preliminarily dismiss portions of a Complaint filed against a construction company, and, shortly thereafter, negotiated the voluntary withdrawal of the lawsuit.

  • Represented families in connection with the appointment of guardians of the person and estate of incapacitated individuals.

  • Represented colleges, universities, private schools, and business entities to conduct in-depth investigations into allegations of, among other things, hostile work environment, inappropriate sexual conduct, discrimination, and hazing.