William N. Finnegan IV

  • Partner
  • Ebill.finnegan@lw.com
  • 301 Congress Avenue
  • Suite 900
  • Austin, Texas 78701
  • United States
  • T +1.713.546.5400
  • 811 Main Street
  • Suite 3700
  • Houston, TX 77002
  • USA
  • T +1.713.546.7410


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 2005-2021 and Chambers Global from 2014-2021   
  • “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 Best Lawyers* from 2003-2022 (Best Lawyers is by BL Rankings)
  • Named among the 500 Leading Dealmakers in America by Lawdragon, 2021-2022
  • 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 2019 for his work in Capital markets, M&A, and Private Equity

Mr. Finnegan is a member of the Texas Bar Foundation, Houston Bar Foundation, and the American Bar Association.


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:
  • Chesapeake Energy Corporation — US$2.2 billion acquisition of Vine Energy
  • Riverstone Holdings LLC — US$1.5 billion acquisition by Silver Run Acquisition Corporation of Centennial Resource Development
  • Energy Transfer Partners LP — US$18 billion acquisition of Regency Energy Partners LP
  • Energy Transfer Equity, L.P. — US$1.04 billion sale by Southern Union Company, a subsidiary of Energy Transfer Equity, L.P., of Missouri Gas Energy and New England Gas Company, natural gas distributors, to The Laclede Group, Inc.
  • Energy Transfer Partners LP — US$5.3 billion acquisition of Sunoco Inc.
  • Energy Transfer Equity, L.P. — US$9.4 billion acquisition of Southern Union Company
  • Rowan Companies, Inc. — US$1.1 billion sale of LeTourneau Technologies to Joy Global, Inc.
  • Rowan Companies, Inc. 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 LP in its US$385 million initial public offering (Counsel to the Company)
  • Westlake Chemical Partners LP in its US$270 million initial public offering (Counsel to the Underwriters)  
  • Phillips 66 — US$434.44 million initial public offering (Counsel to the Company)
  • MPLX LP in its US$437 million initial public offering (Counsel to the Company)
  • Tesoro Partners LP 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 LP — multiple debt and equity offerings totaling more than US$30 billion in aggregate (Counsel to the Company)
  • Regency Energy Partners LP — multiple debt and equity offerings totaling more than US$7 billion in aggregate (Counsel to the Company)

Thought Leadership

  • Midstream MLP Merger Mania Maintains Momentum -  October 30, 2014
  • Four Trends in Master Limited Partnership M&A in 2014 -  October 01, 2014

According to sources:

"He is a fantastic lawyer."

"He stays on top of things and he inspires confidence in his clients – you want him on your transaction."

Chambers USA 2021
Bar Qualification
  • Texas
  • JD, University of Houston Law Center, 1981
    magna cum laude
  • BBA, University of Texas, 1978
    with honors
  • Energy & Infrastructure
  • Capital Markets
  • Public Company Representation
  • Master Limited Partnerships
  • Mergers & Acquisitions
  • Private Equity