William A. Maher, Partner

Litigation & Dispute Resolution Group


William Maher is a founding member of the Firm, and leads the Firm’s Litigation & Dispute Resolution Group. In his more than 30 years of practice, Bill has had broad experience in litigating, arbitrating or mediating complex commercial disputes, has tried numerous cases and arbitrations, and has argued appeals in both state and federal court. Bill has represented various financial entities in disputes arising from or relating to the collapse of the residential mortgage-backed securities (“RMBS”) market, including RMBS issuances, debt obligations, derivative instruments tied to RMBS and guarantees of bonds by insurers. For the last eleven years, Bill has been recognized by Chambers USA (a leading independent evaluator of lawyers and law firms) as a leading lawyer for business disputes in New York. In 2017, Chambers USA described him as a "very skilled litigator [whose] . . . practice includes arbitrations as well as high-stakes trial proceedings."


Bill received his J.D. degree from The University of Virginia School of Law, where he graduated at the top of his class as Order of the Coif and was the Managing Editor of the Virginia Law Review. He received his B.A. degree in Economics from The College of William & Mary.

Illustrative Professional Experience

  • Represents Lehman Brothers Holdings Inc., and certain affiliated entities (collectively, "Lehman"), in numerous disputes, including litigations asserting indemnification claims against more than 100 mortgage loan sellers relating to Lehman’s multi-billion dollar settlements of claims litigation with (i) Fannie Mae and Freddie Mac, and (ii) trustees for hundreds of RMBS trusts. In re Lehman Brothers Holdings Inc., et al., Case No. 08-13555 (SCC) (Bankr. S.D.N.Y.), Adversary Proceeding No. 16-01019 (SCC). Previously, Bill represented Lehman in, among other matters, (i) a litigation relating to Archstone, the largest real estate holding of Lehman, which was purchased by Lehman and others in 2007 for approximately $22 billion, In re Lehman Brothers Holdings, Inc., et al., Case No. 08-13555 (JMP) (Bankr. S.D.N.Y.), Adversary Proceeding No. 11-02928 (JMP), and (ii) a lawsuit against an affiliate of Goldman Sachs & Co. for breach of an approximately $1.3 billion contract related to an office building portfolio in Virginia. Rosslyn LB Syndication Partner LLC v. USREO/Rosslyn Investors, LLC, Chapter 11 Case No. 08-13555 (JMP) (Bankr. S.D.N.Y.), Adversary Proceeding No. 11-02764 (JMP).
  • Represents the directors of an insurance company in a purported class action lawsuit against them arising out of the insurance company's demutualization and its simultaneous acquisition in October 2018 for approximately $2.5 billion by a member of the Berkshire Hathaway Group of Insurance Companies. Castagna, et al. v. Capotorto, et al., Index No. 516767/2018 (N.Y. Supreme Court, Kings County).
  • Represents three interest rate swaps ("IRS") trading platforms against 11 of the largest IRS dealers, including Bank of America, Citigroup, Goldman Sachs, and J.P. Morgan, alleging that the IRS dealers conspired to boycott these three IRS trading platforms in an effort to undermine competition in the IRS market. In re Interest Rate Swaps Antitrust Litigation, No. 16-md-2704 (PAE) (S.D.N.Y.).
  • Represented Assured Guaranty (UK) Ltd., as financial guarantor of hundreds of millions in bonds, in a lawsuit against an affiliate of JPMorgan Chase for investing and then maintaining the underlying portfolios in subprime and Alt-A mortgage-backed securities, thereby causing very significant losses. Assured Guaranty (UK) Ltd. v. J.P. Morgan Investment Management Inc., Index No. 603755/08 (N.Y. Supreme Court, N.Y. County). In March 2017, after two weeks of trial, the case settled on confidential terms. Previously, on an issue of major significance in the case and to investors generally, Bill obtained a unanimous landmark ruling from New York’s highest court that New York’s “blue sky” law, known as the Martin Act (N.Y. Gen. Bus. Law § 352-59), does not preempt common-law tort claims for negligence and breach of fiduciary duty in the securities field. Assured Guaranty (UK) Ltd. v. J.P. Morgan Investment Management Inc., 18 N.Y.3d 341 (2011).
  • Represented Mizuho Bank, Ltd. ("Mizuho") as a defendant in a purported class action litigation seeking hundreds of millions in damages against defendants for numerous alleged wrongdoings that purportedly prevented plaintiffs from redeeming bonds issued by Germany for the funding of war reparations. Bleier, et al. v. Bundesrepublik Deutschland a/k/a Federal Republic of Germany, et al., No. 08-cv-6524 (N.D. Ill.). In 2012, the District Court dismissed all claims against all defendants with prejudice, which ruling was affirmed in 2014 by the United States Court of Appeals for the Seventh Circuit. These rulings represented a complete victory for all defendants, including Mizuho.
  • Represented Assured Guaranty Municipal Corp. (“Assured Guaranty”), against three affiliates of The Royal Bank of Scotland Group plc (“RBS”) that had created a residential mortgage-backed securities structure known as Soundview Home Loan Trust 2007-WMC1. In 2014, the United States District Court for the Southern District of New York (Koeltl, J.) denied the RBS Defendants' motion to dismiss Assured Guaranty’s claims for common law fraud and for aiding and abetting common law fraud. Assured Guaranty Municipal Corp. v. RBS Securities Inc., et al., No. 13-cv-2019 (JGK) (S.D.N.Y.). The case subsequently settled on confidential terms.
  • Represented certain junior noteholders in two related interpleader lawsuits involving collateralized debt obligations (“CDOs”). See In re LNR CDO IV, Ltd., No. 13-cv-2239 (JSR) (S.D.N.Y.), and In re JER CRE CDO 2005-1, Limited, No. 13-cv-2232 (JSR) (S.D.N.Y.). Senior noteholders in both CDOs attempted to cut off all payments to junior noteholders. On December 31, 2013, Bill prevailed in his summary judgment argument that the Trustee was required under the Indentures to “rescind and annul” the senior noteholders’ declaration of acceleration, thereby requiring the Trustee to distribute tens of millions of dollars to the junior noteholders that had been withheld pending the resolution of the dispute. The senior noteholders did not appeal the District Court’s Order.
  • Represents insurance companies as cedents, reinsurers and/or retrocessionaires in confidential arbitration proceedings. Although most of these proceedings are non-public, arbitration awards sometimes become public when one of the parties seeks to confirm the arbitration award in court. For example, the Firm filed a petition to confirm an arbitration award on behalf of its client, Minnetonka Insurance Company, which prevailed in virtually every respect in the underlying arbitration. Minnetonka Insurance Co. v. Lloyd’s Syndicate SJC-2003, et al., No. 11-cv-6592 (DAB) (S.D.N.Y.). That arbitration involved Minnetonka’s effort to enforce reinsurance agreements with respect to a claim in excess of $220 million submitted to it by Minnetonka’s insured in connection with the flooding of its facility in Cedar Rapids, Iowa, as well as other locations around the country.
  • Represented two insurance companies seeking to recover tens of millions in reinsurance balances and interest due under various reinsurance agreements. Chartis Property Casualty Co., et ano. v. Transatlantic Reinsurance Co., Index No. 652337/2011 (N.Y. Supreme Court, N.Y. County). In December 2015, the case settled on confidential terms while summary judgment motions were pending.
  • Represented Mizuho Bank, Ltd. ("Mizuho") against claims that it breached a multi-million dollar letter of credit that it had issued to facilitate an international commercial transaction between companies in the U.S. and Taiwan. In 2011, Bill was successful in obtaining summary judgment on behalf of Mizuho. CVD Equipment Corp. v. Taiwan Glass Industrial Corp., et al., No. 10-cv-0573 (RJH) (S.D.N.Y.), 2011 U.S. Dist. LEXIS 35791.
  • Represented an affiliated group of insurance companies against claims for many tens of millions in damages pursuant to a joint venture agreement and a reinsurance agreement. Bill was successful in having the claims dismissed at the summary judgment stage, which ruling ultimately was upheld by the Ohio Supreme Court. Olympic Holding Co., LLC, et al. v. ACE Limited, et al., 909 N.E.2d 93 (Ohio Supreme Court 2009).

Articles and Presentations

Faculty Member at presentation on “Difficult Issues in Arbitration – Even for Experienced Arbitrators” (New York, NY, March 14, 2013)

Faculty Member at presentation on oral and written communications and the scope of applicable privileges (New York, NY, July 28, 2011 & September 26, 2011)

Faculty Member at presentation on litigating issues arising from settlement agreements (Boston, MA, October 22, 2010)

Faculty Member at mock arbitration for training arbitrators (New York, NY, November 11, 2009)

Faculty Member at mock arbitration for training arbitrators (New York, NY, November 6, 2008)

Faculty Member at litigation & arbitration conference (Philadelphia, PA, September 8, 2008)

Faculty Member at mock arbitration for training arbitrators (Tarrytown, NY, September 3, 2008)

Special Editor for the Association of Insurance & Reinsurance Run-Off Companies (“AIRROC”), Special Issue on Dispute Resolution, AIRROC Matters Newsletter, Spring 2008, Volume 4, No. 1 (published May 2008)

Faculty Member at mock arbitration for training arbitrators (Boca Raton, FL, May 10, 2007)

Other Activities

Member, Board of Trustees, Ranney School (Grades K-12, Tinton Falls, NJ) (2014-Present)