About MARK
Mark represents businesses and individuals in a wide range of disputes, including complex matters involving contracts, trade secrets, unfair competition, construction claims, and real estate conflicts. He is known for his practical approach to resolving high-stakes litigation while guiding clients through every stage of the process.
Specialties
Admin Contact
Kelly M. DiBonaventure
KDiBonaventure@HRMML.com
Mark F. Himsworth
(215) 661-0400 • MHimsworth@HRMML.com
Mark Himsworth is a seasoned commercial litigator with more than 25 years of experience representing businesses and individuals in complex disputes. A member of the Litigation Department at Hamburg, Rubin, Mullin, Maxwell & Lupin, Mark’s practice covers a wide range of business and real estate conflicts.
He regularly handles matters involving covenants not to compete, interference with contractual relations, unfair competition, misappropriation of trade secrets, commercial defamation, and partnership or shareholder disputes. In addition, Mark represents clients in construction litigation, including construction defect claims, mechanic’s lien actions, municipal bid challenges, consumer protection claims, and payment and performance bond disputes. He also frequently advocates for residential and commercial brokers in malpractice and commission cases and counsels clients in real estate disputes such as quiet title actions, partition and adverse possession claims, deed restrictions, lis pendens, agreements of sale disputes, and tax assessment appeals.
Mark is a Fellow of the Litigation Counsel of America, an invitation-only honorary society recognizing fewer than one-half of one percent of American lawyers for excellence in trial advocacy and litigation. He has also been recognized on the Pennsylvania Super Lawyers list for Business Litigation every year from 2010 through 2023—an honor awarded to no more than five percent of attorneys statewide.
Deeply engaged in both the legal and local communities, Mark serves on the Board of Directors of the Montgomery Bar Association, is a past President of the Montgomery Trial Lawyers, and is an active Barrister with the Montgomery Inn of Courts. He also contributes to civic and nonprofit organizations, currently serving on the Advisory Council of the PennSuburban Chamber of Commerce and having previously served with the Patrician Society, the United Fund of Collegeville-Trappe, and as President and counsel for Big Brothers Big Sisters of Montgomery County. He is also a former member of the Trappe Borough Planning Commission.
Mark earned his B.A. from the University of Notre Dame in 1984 and his J.D. from Widener University School of Law in 1987.
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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).
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Admissions
Pennsylvania
Education
Widener University School of Law (J.D. 1987)
University of Notre Dame, (B.A. Accounting 1984)
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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
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Bankruptcy law creates a conundrum for warehouse operators holding payments,ACWI Advantage, publication of the American Chain of Warehouses, February 15, 2021
Make Sure Your Remote Corporate Meetings Follow Corporate Formalities, HRMM&L Legal Spotlight, January 18, 2021
In a Limited Liability Company, Majority Rule Doesn’t Necessarily Rule, HRMM&L Legal Spotlight, January 15, 2019
After “Reelin’ In the Years and Stowin’ Away the Time” Revisit Your Buy-Sell Agreement, HRMM&L Legal Spotlight, June 26, 2018
If a Provision of a Non-Competition Agreement is Overbroad, There is a Risk that the Entire Agreement May Be Thrown Out, HRMM&L Legal Spotlight, November 13, 2017
An Accountant’s Liability for a Client’s Loans, What? HRMM&L Legal Spotlight, October 30, 2017
If You Had the Chance to Choose Home Court Advantage, Why Wouldn’t You? HRMM&L Legal Spotlight, September 13, 2017
To Catch a Thief: Understanding the World of Trade Secrets and Making Non-Competes Work for You,” HRMM&L Business Advisory Group Seminar, June 21, 2017
New Changes to Pennsylvania’s Mechanic’s Lien Law Will Impact Some Construction Projects, HRMM&L Legal Spotlight, January 17, 2017
If You Think That Attorney’s Fees are Recoverable in a Suit for a Tenant’s Breach of a Residential Lease, Think Again, HRMM&L Legal Spotlight, June 17, 2016
Where There’s a Will, There’s a Way, HRMM&L Legal Spotlight, May 10, 2016
Recent Bills Signed by Governor Corbett Affecting Oil and Gas Leases, HRMM&L Client Alert, October 2014
Selling Real Estate on the Shale, Bradford Sullivan Association of Realtors, July 2010
Oil and Gas Company Was a Couple Days Late and a Couple Dollars Short, HRMML Gas Lease and Development Update, March 2011
Residents’ Suit Against Oil and Gas Company Survives Challenge, HRMML Gas Lease and Development Update, December 2010
Recent Ruling Gives Life to a Homeowners’ Challenges to the Validity of an Oil and Gas Lease, HRMML Gas Lease and Development Update, December 2010
The Home Improvement Consumer Protection Act, HRMML Real Estate Update, May 2009
Real Estate Agents Beware: Your Commission MUST be in Writing, In Brief HRMML Newsletter, March 2008
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Fellow of the Litigation Council of America
Named to the Pennsylvania Super Lawyers List for Business Litigation for the years 2010-2025. No more than five percent of the lawyers in the state are selected by Super Lawyers each year.
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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.