Jeannemarie O’Brien is a partner in the New York law firm of Wachtell, Lipton, Rosen & Katz, where she is active in the firm’s merger and acquisition practice, focusing on the executive compensation and employee benefits aspects of transactions, with a particular emphasis on transactions involving financial services institutions. O'Brien has been involved in many major domestic and international merger, acquisition and buyout transactions, strategic defense assignments and proxy contests. O’Brien also advises companies and their boards on governance issues and assists companies and senior executives on executive compensation matters in both the public and private sectors.
Transactions in which O’Brien has recently been involved include many major financial institution transactions, both bank and non-bank, and transactions in a variety of other industries, including:
- Capital One in its pending $35.3 billion acquisition of Discover Financial Services
- AbbVie in its $10.1 billion acquisition of ImmunoGen
- Hess Corporation in its pending $60 billion all-stock acquisition by Chevron Corporation
- BGC Group, Inc. in the investment by a consortium of 10 banks into FMX
- RTX Corporation in its $1.3 billion sale of its Cybersecurity, Intelligence & Services business
- The Goldman Sachs Group Inc. in its sale of its GreenSky platform and associated loan assets to Sixth Street and in partnership with others
- The Cigna Group in its sale of its Medicare Advantage, Cigna Supplemental Benefits, Medicare Part D and CareAllies businesses to Health Care Service Corporation
- PGA TOUR in an up to $3 billion investment by Strategic Sports Group in PGA TOUR Enterprises
- Greenhill in its $550 million all-cash acquisition by Mizuho
- American International Group in its $4.5 billion sale of its Validus Re business to RenaissanceRe Holdings Ltd
- The PNC Financial Services Group in its $11.6 billion acquisition of BBVA USA Bancshares
- Webster Financial Corporation in its $10.3 billion all-stock merger of equals with Sterling Bancorp
- BMO Financial Group in its $16.3 billion acquisition of Bank of the West
- United Technologies in its $147 billion merger of equals transaction of its Aerospace business with Raytheon, forming Raytheon Technologies Corporation, and its spinoffs of Otis Worldwide and Carrier Global
Lawdragon Honors
| Honor | Year | Practice |
|---|---|---|
| The 2026 Lawdragon 500 Leading Corporate Employment Lawyers | 2026 | Executive Compensation & Benefits |
| The 2025 Lawdragon 500 Leading Corporate Employment Lawyers | 2025 | Executive Compensation & Benefits |
O’Brien received a B.A,. cum laude, from Mount Holyoke College and a J.D., cum laude, from Fordham Law School, where she was an associate editor of the Fordham Law Review. She is a member of the New York State and American Bar Associations.
Select Publications
- Financial Institutions MA Key Trends and Outlook,
in Harvard Law School Forum on Corporate Governance, February 3, 2025.
- Compensation Season 2025,
in Harvard Law School Forum on Corporate Governance, January 23, 2025.
- Wachtell Publishes Financial Institutions M&A Guide for 2024,
in NYU Law School’s Blog on Compliance and Enforcement, May 8, 2024.
- Compensation Season 2024,
in Columbia Law School’s Blog on Corporations and the Capital Markets, January 29, 2024 and Harvard Law School Forum on Corporate Governance, January 30, 2024.
- Compensation Season 2023,
in Harvard Law School Forum on Corporate Governance, January 20, 2023.
- Integrating, Retaining and Providing Benefits and Incentives to Employees of a Joint Venture,
in Partnerships, Joint Ventures & Strategic Alliances (Law Journal Press, 2022).
- Compensation Season 2022,
in Harvard Law School Forum on Corporate Governance, January 9, 2022 and Columbia Law School’s Blog on Corporations and the Capital Markets, January 11, 2022.
- 2021 Proxy Season: Executive Compensation Considerations,
in Harvard Law School Forum on Corporate Governance, February 15, 2021.
- Compensation Season 2021,
in Harvard Law School Forum on Corporate Governance, January 14, 2021.
- Executive Compensation Considerations - Looking Ahead and Staying Nimble,
in Columbia Law School’s Blog on Corporations and the Capital Markets, August 25, 2020.
- Covid-19: What Compensation Committees Should Be Thinking About Today,
in Harvard Law School Forum on Corporate Governance and Financial Regulation, March 31, 2020.
- Compensation Committee Guide - 2020,
in Harvard Law School Forum on Corporate Governance and Financial Regulation, March 19, 2020.
- Compensation Season 2020,
in Harvard Law School Forum on Corporate Governance and Financial Regulation, January 23, 2020.
- Compensation Committee Guide - 2019,
in Harvard Law School Forum on Corporate Governance and Financial Regulation, April 26, 2019.
- Compensation Season 2019,
in Harvard Law School Forum on Corporate Governance and Financial Regulation, January 11, 2019.
- Compensation Season 2018,
in Harvard Law School Forum on Corporate Governance and Financial Regulation, January 9, 2018.
- 2018 Proxy Season: Five Ways to Improve Your Compensation Disclosure,
in Harvard Law School Forum on Corporate Governance and Financial Regulation, November 25, 2017.
- Compensation Season 2017,
in Harvard Law School’s Forum on Corporate Governance and Financial Regulation, January 7, 2017.
- FINANCIAL INSTITUTIONS DEVELOPMENTS - Significant Activity in All Sectors as Financial Institutions Innovate and Evolve,
in Harvard Law School Forum on Corporate Governance and Financial Regulation, October 12, 2016.
