International Corporate / M&A

Guide Locations

International Corporate / M&A

Published November 2022


Alan Klein

Firm: Simpson Thacher & Bartlett LLP
Country: USA - New York

Practice Area: Corporate

  • 425 Lexington Avenue
    New York
    NY 10017

Simpson Thacher & Bartlett LLP is one of the world’s most respected law firms. But for us, this has never simply been a matter of size or rankings. It’s the direct result of our commitment to one founding principle.

Our success is driven by that of our clients.

Since 1884, many of the world’s largest organisations have turned to us for smart solutions to critical commercial challenges. Today, more than 900 lawyers in 10 global offices put the collective experience of the Firm to work for every client we serve.

Our teams start with a deep understanding of our clients’ business objectives. We share knowledge across practices and regions. We help our clients not only mitigate risk, but also discover opportunity. And each success begins with the same simple question...

How can we help you?


Simpson Thacher is home to more than 900 lawyers, many of whom have spent their entire careers here, collaborating on behalf of our clients.


Many of the world’s leading and most innovative companies – from finance to philanthropy and from Fortune 500 to high-tech startups – come to Simpson Thacher for trusted counsel.


From 10 offices, across 32 major practice areas and almost every industry sector, we bring the collective expertise of the entire firm to bear on the business challenges facing each one of our clients.


We consistently rank among the world’s leading law firms in a wide variety of publications – including Chambers, Bloomberg, Refinitiv, The Legal 500, IFLRand American Lawyer.

Corporate Law

Corporate transactions are a core feature of the modern commercial world; Simpson Thacher offers a pragmatic, straightforward and collaborative approach to help our clients attain their goals through these transactions.

“They are cutting edge, very practical and extremely smart.” Chambers USA 2016 (quoting a client)

As leaders across all corporate disciplines, we regularly advise on a range of complex transactions, including mergers and acquisitions, equity and debt capital markets offerings, joint ventures, project financings and infrastructure development, structured financings, private fund formation and investments, syndicated loans, debt restructurings and bankruptcies, and privatisations.

The versatility of our practice areas greatly benefits clients – banks, companies, private equity firms, public utilities, nonprofits and individuals. We regularly advise clients such as Alibaba Group, Apax Partners, Bank of America Merrill Lynch, Blackstone, Carlyle, Dell, EQT, First Reserve, Goldman Sachs, HCA, Hellman & Friedman, Hilton, JPMorgan, KKR, Microsoft, the Republic of Peru, Seagate Technology, Silver Lake Partners, SiriusXM, Travelers and scores of others.

By assembling multidisciplinary teams, we counsel clients on increasingly intricate transactions with ingenuity and efficiency. Independent rankings attest to our unsurpassed leadership in the marketplace. We consistently rank at the top in both US and global evaluations by publications such as Chambers, The Legal 500 and the International Financial Law Review.

“We think of Simpson Thacher for high-profile transactions.” Chambers Global 2016 (quoting a client)

Alan Klein

Alan Klein is a Partner with Simpson Thacher & Bartlett LLP, where he practices in the Corporate Department and is Co-Head of the Firm’s Mergers and Acquisitions Practice and a member of the Executive Committee. Alan’s practice concentrates on mergers and acquisitions, shareholder activism and corporate governance matters.

Alan has represented Microsoft Corporation in connection with its $28.2 billion acquisition of LinkedIn, its $7.2 billion acquisition of Nokia’s phone business, its acquisition of Skype for $8.5 billion in cash from the investor group led by Silver Lake and in its investment in Barnes & Noble’s Nook business, as well as in its approach to Yahoo! Inc.

In addition, he recently represented Aetna’s Board of Directors in connection with CVS Health’s acquisition of Aetna for $69 billion; The ADT Corporation in its $15 billion sale to Apollo Group Management; Johnson Controls in the sale of its Scott Safety business to 3M for approximately $2 billion and Tyco International Ltd. in connection with a number of transactions, including its $20 billion merger with Johnson Controls, Inc.; its separation into three independent, publicly traded companies and the multibillion-dollar merger of its Flow Control business with Pentair, Inc.; its acquisition of Chemguard, Inc.; its $300 million acquisition of a 75% equity stake in privately held KEF Holdings Ltd.; its $2 billion cash and stock acquisition of Brink’s Home Security Holdings, Inc., now operating as Broadview Security and its sale of a majority interest in its Electrical & Metal Products business. He also represented Best Buy in a take-private offer by its founder and former chairman.

Alan has also been involved in many cross-border M&A transactions around the world during the last decade, including representing ChemChina in its $43 billion acquisition of Syngenta; Chinalco in its $12 billon investment in Rio Tinto plc; Gas Natural S.A. in its $30 billion bid for Endesa S.A.; Royal Ahold in connection with its merger of equals with Delhaize Group; ADT in its CAD $550 million acquisition of Protectron; Rinker Group Limited in connection with its $15 billion acquisition by Cemex S.A.B. de C.V.; Portugal Telecom S.A. in connection with the unsolicited offer made for it by Sonae S.A.; Gerdau S.A. in its acquisition of Quanex Corporation; Bavaria S.A., Latin America’s second-largest brewer, in its sale to SABMiller plc; Owens-Illinois Inc. in its acquisition of French packaging company BSN Glasspack from CVC Europe and in its disposition of Owens-Brockway Plastic Products Inc.; Merck & Co, Inc. in its tender offer for shares of Banyu, a Japanese pharmaceutical company; Telefonica Moviles S.A. in its acquisition of certain non-U.S. cellular phone companies from Motorola Inc. and Pechiney in its proposed three-way merger with Alcan Aluminum and Alusuisse.

Alan is the past Co-Chair of the International Bar Association’s Corporate and M&A Law Committee. For the past seven years, he has chaired the International Bar Association’s Annual International Mergers and Acquisitions Conference in New York City.

Alan recently authored a chapter entitled “Avoiding the Pitfalls and Reaping the Benefits of Cross-Border M&A Deals” in Structuring International M&A Deals: Leading Lawyers on Managing Mergers & Acquisitions in a Global Environment, published by Aspatore Books, a Thomson-Reuters business.

From 1994 to 1998, Alan was resident in the Firm’s London office, and worked on international transactions, including the merger of Glaxo plc and Wellcome plc; the acquisition of Affymax N.V. by Glaxo; the acquisition by Owens-Illinois, Inc. of the glass and packaging business of BTR plc; the acquisition of Yorkshire Electricity plc by American Electric Power and its partner New Century Energy, as well as initial public offerings by British, French, Italian, Norwegian and Swedish companies.

Alan joined the Firm in 1984 and became a Partner in 1993. Alan received his B.A. with Honors in history in 1981 from Haverford College. He received his J.D., cum laude, from Harvard Law School in 1984. Alan was named a 2017 “M&A Trailblazer” by the National Law Journal. He was also named a 2012 MVP by Law360 for his leadership in M&A, including closing within one year several of the market’s most significant M&A deals with a combined transaction value of more than $18 billion. In addition, Alan was selected as a 2012 “Dealmaker of the Year” by The American Lawyer. He was chosen for leading the Simpson Thacher team representing Microsoft in connection with its $8.5 billion acquisition of Skype. He is recognised in Chambers Global: The World’s Leading Lawyers for Business, Chambers USA: America’s Leading Lawyers for Business, The International Who’s Who of Mergers and Acquisitions Lawyers, and The International Who’s Who of Corporate Governance Lawyers, as well as by IFLR1000 as a leading mergers and acquisitions lawyer.


•             Montefiore Medical Center, Member, Board of Trustees (2007–Present)

•             Film Forum, Chair, Board of Directors (2013-Present), Member, (2005-2013)

•             Lawyers for Children, Member, Board of Directors, (1999–Present)

•             LaGuardia/Wagner New York City Mayoral Archives, Member, Advisory Board (2007-Present)

•             Volunteers of America – Greater New York, Inc., Member, Board of Directors (2000–2007)

•             Citizens Budget Commission, Trustee (2000–2012)

•             Association of the Bar of the City of New York

•             American Bar Association

•             International Bar Association

•             New York State Bar Association

Work Highlights

•             Aetna’s Board of Directors in connection with CVS Health’s $69 billion acquisition of Aetna

•             Ahold in its $29 billion merger of equals with Delhaize Group

•             Chinalco in its $14 billion acquisition of a minority stake in Rio Tinto and in its subsequent $19.5 billion investment in Rio Tinto

•             Tyco International in various transactions, including its separation into three independent, publicly traded companies and its $2 billion acquisition of Brink’s Home Security Holdings

•             Gas Natural S.A. in its $30 billion bid for Endesa S.A.

•             Rinker Group Limited in its $15 billion acquisition by Cemex S.A.B. de C.V.

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