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
Apergy Corporation
athenahealth, Inc.
Atos S.E.
in its $3.57 billion acquisition of Syntel, Inc.
Belmond Ltd.
Brookfield Asset Management Inc.
- and Brookfield Property Partners L.P. (BPY) in BPY's $14.4 billion acquisition of the approximately 66% of common stock that it did not already own of GGP Inc. (f/k/a General Growth Properties Inc.).
- in its approximately $4.8 billion acquisition of a 61.2% stake in Oaktree Capital Group, LLC.
- in its $2.8 billion acquisition of all of the outstanding common shares not already owned by Brookfield Property Partners L.P. of Rouse Properties, Inc., a REIT that owns and manages regional shopping malls in the United States.
Campbell Soup Company
Churchill Capital Corp III
Dow
- The Dow Chemical Company in its $130 billion all-stock merger of equals with E. I. du Pont de Nemours and Company.
- Dow in its approximately $40 billion spin-off from DowDuPont Inc. as part of DowDuPont's separation into three independent, publicly traded companies, one each for its agriculture, materials science and specialty products businesses.
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 world-wide rights to an intranasal glucagon from Locemia, and the North American rights to Erbitux® (cetuximab) (including commercialization and manufacturing responsibilities) from Bristol-Myers Squibb Company; and in the sale of veterinary assets to Virbac SA.
Kinder Morgan
- in its $76 billion acquisition of all of the outstanding equity securities of Kinder Morgan Energy Partners, L.P., Kinder Morgan Management, LLC, and El Paso Pipeline Partners, L.P. — at the time, the largest energy merger since Exxon and Mobil combined in 1999.
- in its $5 billion acquisition of Copano Energy.
- in its $38 billion acquisition of El Paso Corporation, creating one of the largest energy companies in the world and in El Paso’s concurrent $7.15 billion sale of its E&P production business, EP Energy Corporation.
- and Kinder Morgan Canada Limited in their $3.5 billion sale of Trans Mountain Pipelines Inc. and the Trans Mountain Expansion Project to the Government of Canada.
The Kroger Company
- in the $2.15 billion sale of its convenience store business unit to EG Group.
- in its acquisition of Vitacost.com, Inc.
- in its acquisition via tender offer of Roundy’s, Inc.
- in its strategic partnership with, and investment in, Lucky’s Market.
Maxim Integrated Products, Inc.
MGM Resorts International (MGM Resorts)
- in the formation of a joint venture between MGM Growth Properties LLC and Blackstone Real Estate Income Trust to acquire the Las Vegas real estate assets of the MGM Grand and Mandalay Bay for $4.6 billion and to lease back these assets to subsidiaries of MGM Resorts.
- in its $4.25 billion sale of the Bellagio to a joint venture MGM Resorts formed with Blackstone Real Estate Income Trust and its planned leaseback of the Bellagio.
- in its formation MGM Growth Properties LLC (MGP), a controlled REIT, and in corporate, real estate and tax aspects of MGP’s $1.05 billion initial public offering.
- in its $1.175 billion sale of the real property of the Borgata Hotel Casino & Spa in Atlantic City, New Jersey to MGM Growth Properties LLC. The sale followed MGM Resorts’ $900 million acquisition of the 50% interest in the Borgata that it did not already own from Boyd Gaming Corporation.
Nexeo Solutions Inc.
Transaction Committee of the Board of Directors of Reynolds American Inc.
Sanofi
- in its $25 billion exchange of Merial, its animal health business, for the consumer healthcare business of Boehringer Ingelheim GmbH.
- 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 $2.5 billion acquisition of Synthorx, Inc.
- in its $2.35 billion sale of Zentiva to Advent International.
- in its up to $750 million acquisition of Protein Sciences Corporation.
- in its sale of Laboratoire Oenobiol S.A.S. to Vemedia Manufacturing B.V.
Scripps Networks Interactive, Inc.
in its $14.6 billion merger with Discovery Communications, Inc.
Total S.A.
in its $4 billion acquisition of all of the oil and natural gas assets, liabilities, businesses and operations of Anadarko Petroleum Corporation in Mozambique and South Africa.
Willis Towers Watson PLC
- Willis Towers Watson PLC in its proposed $80 billion combination with Aon PLC.
- Willis Group Holdings plc in its $18 billion merger of equals with Towers Watson & Co.
- Willis Towers Watson PLC in its $1.3 billion acquisition of TRANZACT.
Key Contacts



See list of lawyers globally
Shortcut Links
Ranked Tier 1 in M&A Category in the United States for the 10th Year Running
IFLR1000 2022
Winner of “France M&A Legal Adviser of the Year”
Mergermarket European M&A Awards 2022
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 2021; Chambers Global 2022; 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 2022 and Chambers USA 2021
M&A partner Michael J. Aiello Named MVP for M&A
Law360 2020, 2017, 2016
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, Speaking Engagements, Latest Thinking, Firm News & Announcements
Awards and Recognition
- Weil Ranked Tier 1 for M&A in the U.S. for the 10th Year Running Award Brief — IFLR1000 2022
- 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 2022
- Weil Ranked Tier 1 for M&A in New York Award Brief — IFLR1000 2022
- 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
- Weil Named a “Leading” Firm for Corporate/M&A: The Elite in New York, Northern California, Texas and the U.S. Award Brief — Chambers USA 2021
- Weil Named a “Leading” Firm for Corporate/M&A in Massachusetts Award Brief — Chambers USA 2021
- Weil Named a “Leading” Firm for M&A: Large Deals ($1BN+) Award Brief — Legal 500 US 2021
Speaking Engagements
-
NACD’s 2021 Virtual Master Class
Speaker(s):
Michael J. Aiello
August 17, 2021 — Weil Mergers & Acquisitions partner Michael J. Aiello spoke on a panel titled “M&A Activity and the Board’s Role in Integration” as part of NACD’s 2021 Virtual Master Class.
-
The Harvard Business School Association’s 2021 Nonprofit Board Summit: Building High Impact Nonprofit Boards During Dynamic Times
Speaker(s):
Adé Heyliger and
Mark Hoenig
May 6, 2021 — Weil partners Adé Heyliger (Public Company Advisory) and Mark Hoenig (Tax) presented on a panel titled “Risks and Opportunities Through the Legal Lens” as part of The Harvard Business School Associations of Boston, New York and Northern California’s 2021 Nonprofit Board Summit: Building High Impact Nonprofit Boards During Dynamic Times.
Latest Thinking
- UK National Security and Investment Bill Alert — PDF — November 2020
- Delaware Supreme Court Upholds Federal-Forum Provisions for Litigation Under the Securities Act of 1933 Alert — Mergers & Acquisitions — By Michael J. Aiello, John A. Neuwirth, Evert J. Christensen and Amanda K. Pooler — PDF — March 22, 2020
- Key Considerations for Boards Navigating COVID-19 Alert — Mergers & Acquisitions — By Michael J. Aiello — PDF — March 20, 2020
- CFIUS Issues Final Regulations Implementing 2018 Statutory Overhaul Publication — PDF — January 17, 2020
Firm News & Announcements
- Weil to Add M&A Partner Sarah Flaherty in London Press Release — January 17, 2023
- Charles Ching Named 2022 Dealmaker of Asia by Asian Legal Business Firm Announcement — December 29, 2022
- Weil Ranked Among Most Innovative North American Law Firms in 2022 by Financial Times Firm Announcement — December 06, 2022
- Weil Elects 12 New Partners and Announces New Counsel Class Firm Announcement — November 22, 2022
- Weil Shortlisted for Two Awards at Financial Times Innovative Lawyers North America 2022 Firm Announcement — November 18, 2022
- Weil Advises Dstny on Acquisition of easybell Deal Brief — October 28, 2022
- Weil Advises The Kroger Company in its Pending $24.6B Merger with Albertsons Deal Brief — October 17, 2022
- Weil Advises Brookfield Business Partners in its Pending $8B Sale of Westinghouse Electric Company Deal Brief — October 11, 2022