William N. Finnegan IV is a partner in the Austin and Houston offices of Latham & Watkins. He has an extensive practice covering a broad range of corporate and securities transactions, including the representation of issuers and underwriters in public and private offerings of debt and equity securities, negotiating and structuring public and private company acquisitions, forming and financing joint ventures and partnerships, and advising on general corporate and securities transactions.

Mr. Finnegan has been:

  • Recommended for his work in Nationwide Capital Markets and Texas M&A and Capital Markets by Chambers USA from 2005-2022 and Chambers Global from 2014-2023   
  • “Hailed as one of the deans of the capital markets Bar, he continues to garner praise for his longstanding securities law practice.”
    “Brilliant, bright, and creative.”
    Chambers USA 2019-2020
  • Recognized for his work in Corporate and M&A Transactions Law by The Best Lawyers in America from 2003-2024 (Best Lawyers is by BL Rankings)
  • Named among the 500 Leading Dealmakers in America by Lawdragon, 2021-2022, 2024
  • Named a Texas Super Lawyer from 2003-2018, 2020
  • Named 2019 Lawyer of the Year in Corporate Law by Best Lawyers*
  • Recognized by Texas Lawyers’ 2019 Professional Excellence Award for Lifetime Achievement
  • Recognized as a market leader by IFLR1000 United States for his work in Capital markets, M&A, and Private Equity (2019, 2023)

Mr. Finnegan is a member of the Texas Bar Foundation, Houston Bar Foundation, and the American Bar Association, and serves as Chair of Latham's Finance Committee.

Mr. Finnegan has represented some of the largest energy companies in the world, with a specific focus on energy Master Limited Partnerships (MLPs).

Representative M&A transactions include:

  • Occidental Petroleum Corporation on its US$12 billion acquisition of CrownRock 
  • Chesapeake Energy on its $US24 billion combination with Southwestern Energy
  • Enerplus Corporation on its US$11 Billion combination with Chord Energy
  • Chesapeake Energy on its US$2.2 billion acquisition of Vine Energy
  • Riverstone Holdings on its US$1.5 billion acquisition by Silver Run Acquisition Corporation of Centennial Resource Development
  • Energy Transfer Partners on its US$18 billion acquisition of Regency Energy Partners
  • Occidental Petroleum Corporation on its US$1.1 billion acquisition of Carbon Engineering 
  • Energy Transfer Equity in its US$1.04 billion sale by Southern Union Company, a subsidiary of Energy Transfer Equity, of Missouri Gas Energy and New England Gas Company, natural gas distributors, to The Laclede Group
  • Energy Transfer Partners on its US$5.3 billion acquisition of Sunoco Inc.
  • Energy Transfer Equity on its US$9.4 billion acquisition of Southern Union Company
  • Rowan Companies on its US$1.1 billion sale of LeTourneau Technologies to Joy Global
  • Rowan Companies, in a Share Purchase Agreement and cross border exchange offer with Skeie Drilling and Production ASA, a Norwegian public limited company

Representative Capital Markets transactions include:

  • CONE Midstream Partners in its US$385 million initial public offering (Counsel to the Company)
  • Westlake Chemical Partners in its US$270 million initial public offering (Counsel to the Underwriters)  
  • Phillips 66 in its US$434.44 million initial public offering (Counsel to the Company)
  • MPLX in its US$437 million initial public offering (Counsel to the Company)
  • Tesoro Partners in its US$273 million initial public offering (Counsel to the Company)
  • Summit Midstream in its US$287.5 million initial public offering (Counsel to the Company)
  • Southcross Energy Partners in its US$180 million initial public offering (Counsel to the Company)
  • Energy Transfer on multiple debt and equity offerings totaling more than US$60 billion in aggregate (Counsel to the Company)
  • Regency Energy Partners on multiple debt and equity offerings totaling more than US$7 billion in aggregate (Counsel to the Company)

Bar Qualification

  • Texas


  • JD, University of Houston Law Center, 1981
    magna cum laude
  • BBA, University of Texas, 1978
    with honors