Mergers & Acquisitions
Weil has helped advise clients on some of the largest and most innovative transactions in the marketplace. In the last year alone, Weil has advised on more than 100 transactions larger than $1 billion for clients in a range of sectors and geographies.
Notable Representations, Key Contacts
Strategic Business Partners in Global M&A
Thinking Outside the Box
Boards of Directors, Special Board Committees and Governance
We have substantial experience assisting Boards of Directors and Special Board Committees with internal investigations, governmental investigations and litigation (including securities, class action and derivative litigations arising out of M&A transactions involving affiliated entities).
Nuanced Understanding of Activism and Takeover Defense

Significant Recent Global M&A Matters
Bell Canada
Brookfield Asset Management Inc.
- Brookfield Business Partners in its $8 billion sale of Westinghouse Electric Company
- Brookfield Corporation in connection with the spin-off of a 25% interest in its asset management business through a newly listed company, Brookfield Asset Management Ltd.
The Campbell's Company
Cedar Fair
ChampionX
Dun & Bradstreet
DIRECTV
Dow
- The Dow Chemical Company in its $130 billion all-stock merger of equals with E. I. du Pont de Nemours and Company.
- in its approximately $40 billion spin-off from DowDuPont Inc. as part of DowDuPont's separation into three independent, publicly traded companies
Eli Lilly and Company
- in its approximately $8 billion acquisition of Loxo Oncology, Inc.
- in its $5.4 billion acquisition of the animal health business of Novartis AG, making Lilly's animal health business the second-largest animal health company by global revenue.
- in its $1.1 billion acquisition of Dermira, Inc.
- in its acquisitions of CoLucid Pharmaceuticals, Inc., Avid Radiopharmaceuticals, Inc., Lohmann SE, ChemGen Corp.
The Home Depot, Inc.
The Kroger Company
- proposed $24.6 billion merger with Albertsons Companies, Inc.
- in the $2.2 billion sale of its convenience store business unit to EG Group.
- $1.9 billion sale of 413 stores, as well as select banners, distribution centers, offices and private label brands to C&S Wholesale Grocers, LLC
- sale of Kroger Specialty Pharmacy to CarelonRx Inc.
NEOGEN Corporation
Sanofi
- in its $13 billion sale of nearly all of its 20.6% stake in Regeneron Pharmaceuticals, Inc.
- in its $11.6 billion acquisition of Bioverativ Inc.
- in its $4.8 billion acquisition of Ablynx NV.
- in its $3.7 billion acquisition of Principia Biopharma Inc.
- in its $3.2 billion acquisition of Translate Bio, Inc.
- in its $2.9 billion acquisition of Provention Bio Inc.
- in its approximately $2.2 billion acquisition of Inhibrx.
- in its $1.075 billion sale of Enjaymo.
Vonage Holdings Corp.
Sunoco LP
- in its $9.1B Acquisition of Parkland Corporation
- in its approximately $7.3 billion acquisition of NuStar Energy L.P.
Willis Towers Watson PLC
- Willis Group Holdings plc in its $18 billion merger of equals with Towers Watson & Co.
- Willis Towers Watson PLC $632 million sale of TRANZACT
Key Contacts



See list of lawyers globally
Shortcut Links
Michael J. Aiello and Eoghan Keenan Named 2025 “Dealmakers of the Year”
The American Lawyer
Weil Named M&A “Practice Group of the Year”
Law360 2024
Ranked Tier 1 for M&A: Large Deals ($1bn+)
Legal 500 US 2024
Ranked Tier 1 in M&A Category in the United States for the 12th Year Running
IFLR1000 2024
Winner of “France M&A Legal Adviser of the Year”
Mergermarket European M&A Awards 2022
It’s a super, full-service Firm that does cutting-edge deals” and “the Firm always brings its A-team to every deal.”
Chambers USA
They are creative, thoughtful lawyers who can handle anything.”
Chambers USA
Beyond the very high-level legal expertise, the firm stands out for its creativity, legal innovation and strategic sense."
Chambers Europe 2022
Named a “Leading” Firm for Corporate/M&A
Chambers USA 2024; Chambers Global 2023; Chambers Europe 2022
Named “SPAC Legal Advisory Firm of the Year”
Mergermarket North America M&A Awards 2021
M&A Partner Michael J. Aiello Ranked Band 1 for Corporate/M&A
Chambers Global 2024 and Chambers USA 2024
M&A Partner Michael J. Aiello Named MVP for M&A
Law360 2020, 2017, 2016
Recognized for “M&A Deal of the Year, $250-$999 million category” for Advising Main Event Entertainment in its Sale to Dave & Buster’s, Inc.
D CEO and Association for Corporate Growth-DFW Mergers & Acquisitions Awards 2023
It’s a super, full-service Firm that does cutting-edge deals” and “the Firm always brings its A-team to every deal.”
Chambers USA 2021
Diverse, talented group of practitioners” who “work seamlessly to drive outcomes and provide guidance and support in complex transactions.”
Legal 500 US 2021
Awards and Recognition, Latest Thinking, Firm News & Announcements
Awards and Recognition
- Michael J. Aiello and Eoghan Keenan Named 2025 “Dealmakers of the Year” Award Brief — The American Lawyer — PDF
- Weil Ranked Tier 1 for M&A: Large Deals ($1bn+) Award Brief — Legal 500 2024
- Weil Ranked Tier 1 for M&A in the U.S. for the 12th Year Running Award Brief — IFLR1000 2024
- Weil Named “France M&A Legal Adviser of the Year” Award Brief — Mergermarket European M&A Awards 2022
- Weil Named “SPAC Legal Advisory Firm of the Year” Award Brief — Mergermarket North America M&A Awards 2021
- Weil Named a “Leading” Firm for M&A in the U.K., France, Germany, China and Hong Kong Award Brief — IFLR1000 2022
- Weil Named a “Leading” Firm for Corporate/M&A, Global-wide and in the U.S., U.K., France and China Award Brief — Chambers Global 2023
- Weil Ranked Tier 1 for M&A in New York Award Brief — IFLR1000 2024
- Weil Named a “Leading” Firm for Corporate/M&A in the U.K. and France Award Brief — Chambers Europe 2022
- Michael J. Aiello Ranked Band 1 for Corporate/M&A in New York Award Brief — Chambers USA 2024 and Chambers Global 2024
- Weil Named a “Leading” Firm for Corporate/M&A: The Elite in New York, Texas and the U.S. Award Brief — Chambers USA 2025
Latest Thinking
- IPOs, Spins and Split-Offs: Capturing the Value of a Separate Business Unit Alert — By Corey Chivers, Amanda Fenster, Sachin Kohli, Joseph M. Pari, Alex P Dobyan and Julia Yu — PDF — June 03, 2025
- Delaware Enacts Conflict Transaction Safe Harbors and Curbs Stockholder Inspection Rights Alert — By Michael J. Aiello, John A. Neuwirth, Caroline Zalka, Lyuba Goltser and Evert J. Christensen — PDF — March 26, 2025
- New Listing Rules for London Publication — By David Avery-Gee, Sarah Flaherty and Murray Cox — July 11, 2024
- Updates to the UK Takeover Code Publication — By Michael Francies, David Avery-Gee, Murray Cox, Sarah Flaherty, Ian Hamilton and Jack Gray — May 03, 2024
Firm News & Announcements
- Weil Advised Catalina in its Sale of NCSolutions to Circana Deal Brief — June 04, 2025
- Four Weil Partners Named 2025 Emerging Leaders by The M&A Advisor Firm Announcement — June 03, 2025
- Weil Advises Sanofi in its $9.5 Billion Acquisition of Blueprint Medicines Deal Brief — June 02, 2025
- Weil Lawyers Shortlisted at IFLR1000’s 2025 Women in Business Law EMEA Awards Firm Announcement — May 13, 2025
- Weil Advises WhiteHawk in Acquisition of PHX Minerals Deal Brief — May 08, 2025
- Weil Advises The Gores Group on $312 Million Upsized IPO of Gores Holdings X, Inc. Deal Brief — May 07, 2025
- Weil Advises Sunoco LP in its $9.1B Acquisition of Parkland Corporation Deal Brief — May 05, 2025
- Weil Honored with Three Awards at 2025 IFLR Europe Awards Firm Announcement — April 04, 2025