Mark Himsworth has been handling commercial litigation matters for over 20 years. A member of the Litigation Department at Hamburg, Rubin, Mullin, Maxwell & Lupin, a considerable amount of his practice is related to business disputes, including cases involving covenants not to compete, interference with contractual relations, unfair competition, misappropriation of trade secrets, commercial defamation, and partnership and shareholder disputes. In addition, he handles a wide spectrum of construction disputes, including construction defect claims, mechanic’s lien claims, unfair trade practice and consumer protection law claims, municipal bid litigation, and payment and performance bond claims. He also represents residential and commercial brokers in broker malpractice cases and in commission disputes and individuals and companies in various real estate disputes, including quiet title actions, partition actions, claims involving adverse possession, lis pendens, easements, deed restrictions, disputes involving both residential and commercial agreements of sale, and tax assessment appeals.

Mark is a Fellow of the Litigation Counsel of America, an invitation-only trial lawyer honorary society whose purpose is to recognize deserving, experienced, and highly qualified lawyers. Membership is limited to 3,500 Fellows, representing less than one-half of one percent of American lawyers. Members are selected and invited into Fellowship after being evaluated on effectiveness and accomplishment in litigation and trial work, along with ethical reputation.

Mark currently serves as a member of the Board of Directors of the Montgomery Bar Association, is a past President of the Montgomery Trial Lawyers and is a member of the Montgomery Inn of Courts as a Barrister and past Treasurer. Mark was named to the Pennsylvania Super Lawyers list for Business Litigation for the years 2010-2022. No more than five percent of the lawyers in the state are selected by Super Lawyers each year. He is a current member of the Advisory Council of the PennSuburban Chamber of Commerce. Mark is a former member of the Board of Directors of the Patrician Society, a non-profit food cupboard devoted to helping the needy in the Norristown area and the United Fund of Collegeville-Trappe, Inc., a non-profit serving various charities in the Collegeville-Trappe area. He is a past President of the Board of Directors of Big Brother/Big Sisters of Montgomery County, and was counsel for that organization. He is also a former member of the Trappe Borough Planning Commission. A graduate of the University of Notre Dame in 1984, Mark obtained his law degree from Widener University School of Law in 1987.


Representative Cases

Business Litigation

  • Represented a paper broker in a case against a paper manufacturer who devised a plan to circumvent Mark’s client and all other brokers and to sell directly to the broker’s end-user customers. The plan was to cut the middle man out. The challenge in the case, and in discovery, was to find actual proof of the unlawful plan. The defendant was based in Michigan, but was acquired by an Australian conglomerate headquartered in the U.S. in Atlanta. Depositions of relevant witnesses were taken in Connecticut and Michigan, without the production of any meaningful documents. The breakthrough in the case came when Mark insisted upon making his own personal inspection of the paper company’s documents and records, all of which had been stored in a trailer and shipped to Atlanta. Mark flew to Atlanta and literally spent two entire days perusing through pages and pages of documents, which were boxed in no particular order in a trailer in the middle of a field outside of the paper mill in Atlanta. Lo and behold, buried in a drawer in an otherwise nondescript, dusty file cabinet, mixed among the boxes, was the evidence of the plot to cut brokers out:  the actual in-house overhead slide presentation of the plan to target brokers. Thereafter, the case promptly settled very favorably for Mark’s client.
  • Successfully defended a former shareholder of a national flood certification business who was sued for allegedly violating a covenant not to compete. Not only did Mark win a verdict for the former owner but, in addition, achieved a judgment in favor of his client in the amount of $120,000.
  • Represented a commercial realtors’ association, which formed a joint venture with two Fortune 500 companies to develop a website specifically for commercial realtors. After the defendants abandoned the joint venture, Mark filed suit. Due to the defendants’ delay in responding to carefully tailored discovery requests, the defendants were precluded by court order from presenting evidence which would refute Mark’s client’s valuation of damages. The case settled shortly thereafter for approximately $400,000.
  • Mark settled a shareholder dispute, whereby he negotiated a $4.35 Million buyout. This case involved contentious litigation in Virginia, and contentious litigation in a related case pending in Pennsylvania.

Construction Litigation

  • Achieved a verdict in favor of an electrical contractor in the amount of approximately $400,000. The significance of the verdict, however, is that it is guaranteed personally by the principals of the defendant, and secured by assets owned personally by the principals of the defendant. Mark’s client provided labor, material and services to the defendant corporation. The defendant’s defense for not paying mounting outstanding invoices was that third parties were not paying it and, alternatively, a dispute as to accounting errors. Mark filed suit, and in just over six months, a verdict was obtained. In preparation for trial, each and every third party who was alleged to have failed to pay the defendant, purportedly resulting in the defendant’s inability to pay the plaintiff, was personally contacted. Each confirmed that in fact the defendant had been paid in full and had been paid very promptly. Once that secret was out, the defendant changed its tune. Not surprisingly, as trial was about to begin, the defendant made an offer of settlement, but with no security. Contemplating piercing the corporate veil to collect on an inevitable judgment against the corporate defendant, an investigation had already been made of the personal assets of the corporation’s shareholders. Those assets were significant. This proved beneficial in negotiating a stipulated verdict, resulting in payment of $125,000 within two months, with the balance to be paid in installments, all secured by personal assets of the principals of the defendant, including a residence, a vacation home on the beach, and a yacht. To the extent that any person failed to execute any documents to secure the obligation, the court retained jurisdiction to enforce compliance.
  • Mark represented a material supplier for a construction job in the city.  After an award of summary judgment in his client’s favor and against the subcontractor, with whom his client had a direct relationship, Mark successfully represented the material supplier against the general contractor, based upon breach of a joint check agreement. An award was entered for the full amount of approximately $100,000, plus interest.  Attorney’s fees were also awarded against the subcontractor.

Real Estate Litigation

  • Represented a family who owned a $1.5 million property that was sold at a tax sale, but because of defects in the sale, Mark was able to successfully set aside the sale and preserve the family estate.
  • Mark represented a defendant sued, based upon allegations of fraud, in connection with an agreement of sale. The plaintiff alleged that there was misrepresentation as to the square footage of the house. Mark filed a motion to dismiss, and was successful.  The case was dismissed in its entirety as to Mark’s client, with prejudice.
  • Mark defended a real estate broker sued in a multi-million dollar class action based upon allegations of RESPA violations.  Mark immediately filed a motion to dismiss, in response to which the plaintiff pulled the plug on the case and voluntarily dismissed it.

Insurance Litigation

  • Represented one of the area’s largest builders in an action brought by the builder’s insurance company seeking to avoid coverage in a case where there was multimillion dollar exposure to the builder. Through creative discovery, Mark obtained some smoking-gun admissions of coverage by the carrier in interoffice memoranda, which ultimately prompted the carrier to acknowledge coverage and pay the lion’s share to settle the underlying litigation.
  • Represented a restaurant owner whose employee sustained a serious back injury in the course of employment, with the likelihood of needing multiple back surgeries. Upon submitting the claim to the Workers’ Compensation carrier, Mark’s client was told that there was no coverage, apparently because the worker’s compensation policy had lapsed. The carrier claimed that notice of the lapse was sent by certified mail to Mark’s client. In the process of filing suit, Mark investigated the protocol used by the U.S. Post Office for bulk certified mailing and learned that in fact no such mail had been mailed by the carrier. Once this was exposed, after suit was filed, the case resolved almost instantaneously. Workers’ Compensation coverage was reinstated and, in addition, Mark’s client recovered all attorneys’ fees and costs.

Banking Litigation

  • Defended a bank sued for racial discrimination in connection with the opening, handling and closing of certain business accounts.  Suit was brought in federal court.  Mark filed a motion to dismiss, which was granted.  Significantly, attorney’s fees were awarded to the bank as a sanction against the plaintiff.
  • Mark also represented an industrial development corporation involved in financing for construction of an industrial complex, which later was leveled as a result of a catastrophic fire.  Mark’s client was subsequently sued in a multi-party, multi-million dollar class action. Mark was the first to file a motion to dismiss on behalf of lenders, and he was successful.  That order became the law of the case.  Mark’s client was dismissed from the case in its infancy avoiding costly protracted litigation.
  • Mark defends banks in cases involving forgeries, unauthorized signatures and endorsements. In one case, which was brought in federal court based upon RICO allegations, Mark was successful in achieving a dismissal of the case as to the bank. The allegations were that employees of the business embezzled money through the use of an account and that they, and others, conspired in a RICO scheme to use the account.

Orphans’ Court Litigation

  • Represents clients in will disputes and in estate administration disputes and guardianship proceedings.
  • Co-counsel for the guardian ad litem in a case concerning the questionable enforceability of multimillion dollar pledges which various non-profits alleged were made by the decedent.
  • Mark represented the executor of the estate of a decedent, where the decedent was accused of misappropriating funds from a decedent, who had given her power of attorney. The executor was sued, based upon allegations that the executor was aware of the misappropriation, and because the funds made their way into a joint account in which the executor was a co-signer, and that he had somehow been unjustly enriched.  Mark filed a motion for summary judgment and was successful, and the case was dismissed against Mark’s client, with prejudice.

Representative Reported Cases:

  • Amplifier Research Corp. v. Hart, 144 B.R. 693 (E.D. Pa. 1992) (representing the plaintiff in a commercial defamation case, successfully defeated a motion to remove the case to Bankruptcy Court and eventually recovered a favorable settlement).
  • Rouse & Associates, Inc. v. Delp, 658 A.2d 1383 (Pa. Super. 1995) (successfully defended against the plaintiff’s attempts to execute on shares of a closely held business).
  • Annenberg v. Commonwealth, 757 A.2d 338 (Pa. 2000) (high-profile, landmark personal-property tax litigation; successful defense of Montgomery County’s personal property tax resulting in a $65 million savings to the County).
  • Israelit v. Montgomery County, 703 A.2d 722, Pa. Commw. 1997, aff’d, 725 A.2d 184 (Pa. 1998) (successful defense of Montgomery County in related landmark class-action personal-property tax litigation; class action dismissed summarily, setting precedent for dismissal of similar class actions which were dismissed subsequently).
  • Palmer v. Security National Bank, 2001 W.L. 877584 (E.D. Pa. 2001) (successfully defended a bank against allegations of racial discrimination and obtained a dismissal of the case and sanctions against the defendant).
  • Lapio v. Robbins, 729 A.2d 1229 (Pa. Super. 1999) (representing the lender against the borrower for breach of an oral $250,000 loan; won summary judgment against the defendant).
  • Hagan v. Olsho, 706 A.2d 1265 (Pa. Super. 1997) (represented a seller in connection with an agreement of sale where the plaintiff alleged fraud; not only was the buyer’s case dismissed in its entirety, but the seller was awarded the deposit money).
  • Lower Providence Township v. Solid Waste Services, Inc. d/b/a J.P. Mascaro & Sons, 747 A.2d 903 (Pa. 1999) (representing the Township in a highly publicized case; within four months of filing suit, due to the waste hauler’s reneging on its Township-wide waste hauling contract, succeeded in a motion for judgment on the pleadings, resulting in a potential savings to the Township and its residents in the amount of approximately $750,000).
  • Winner v. NVR Homes, 754 A.2d 32 (Pa.Super. 2000) (successfully defended a builder in a suit brought by a buyer who claimed to have an option to purchase).
  • Geftman Bros. v. Batt, 817 A.2d 1188 (Pa.Super. 2002) (successfully defended a property owner against a suit brought by a developer claiming deed restrictions were no longer enforceable).




  • Pennsylvania


  • Widener University School of Law (J.D. 1987)
  • University of Notre Dame, (B.A. Accounting 1984)


  • Patrician Society
    • Former Member, Board of Directors
  • United Fund of Collegeville-Trappe, Inc.
    • Former Member, Board of Directors
  • Big Brothers/Big Sisters of Montgomery County
    • Past President, Board of Directors
  • Trappe Borough Planning Commission, Member
  • PennSuburban Chamber of Commerce
    • Member, Advisory Council
  • Perkiomen Valley Chamber of Commerce, Member
  • Pennsylvania Bar Association, Member
  • Montgomery Bar Association
    • Member, Board of Directors
  • Montgomery Trial Lawyers, Past President
  • Montgomery Inn of Courts, Barrister and Treasurer
  • Notre Dame Club of Philadelphia, Member

Publications & Speeches

Honors & Awards

  • Fellow of the Litigation Council of America
  • Named to the Pennsylvania Super Lawyers List for Business Litigation for the years 2010-2022. No more than five percent of the lawyers in the state are selected by Super Lawyers each year.

Personal Interests

Mark is active in his parish at St. Eleanor Church, and he and his wife, Kelly, are the proud parents of three wonderful children, who are busy with school, field hockey, soccer, lacrosse, and ice hockey. Mark and his family also regularly participate in various runs for cancer research, including the Broad Street Run, the Race for the Cure, Run for Your Life, and the Parkway Run.