A&O Shearman

Allen & Overy

George Allen and Thomas Overy founded Allen & Overy (A&O) in London on 1 January 1930 after leaving Roney & Co., bringing several clients with them. Allen became private solicitor to the future Edward VIII in 1935 and advised him during the abdication crisis the following year. His work included helping to draft Edward's broadcast, advising on the legislation permitting his abdication and negotiating his financial settlement. The royal connection brought the young firm wider recognition.

A&O represented Reynolds Metals in the 1958–59 contest for British Aluminium, known as the Aluminium War. Reynolds and Tube Investments, advised by S. G. Warburg & Co., took their offer directly to shareholders after the board favoured an agreement with Alcoa. The dispute helped prompt the 1959 Notes on Amalgamations of British Businesses, a predecessor of the City Code on Takeovers and Mergers introduced in 1968.

In 1963, Allen & Overy acted as English solicitors on the Italian motorway company Autostrade's US$15 million bond issue, arranged by a syndicate led by Warburg. Widely regarded as the first modern Eurobond, it raised dollars outside the United States. A&O's work included addressing British controls on raising capital and the registration requirements for publicly offered bonds.

As the Eurobond market expanded, international finance became a larger part of A&O's business. During the 1970s, its banking practice also grew through syndicated loans, in which several banks lend to one borrower. A&O initially served overseas clients from London, then opened offices in Dubai in 1978, New York in 1985, and Hong Kong and Tokyo in 1988.

After the fall of the Berlin Wall, A&O sought work on the privatisation of state-owned businesses in Central and Eastern Europe. It recruited locally qualified lawyers, adding domestic-law advice to its English-law practice. By 1998, clients outside the United Kingdom accounted for more than two-thirds of revenue.

The firm merged with Italy's Brosio, Casati e Associati that year and took in substantial parts of Loeff Claeys Verbeke in the Benelux countries during 2000–2001. Partners from Germany's Schilling, Zutt & Anschütz also joined A&O in 2000. A 2005 study identified the Netherlands as its second-largest practice by revenue and number of partners, after the United Kingdom and ahead of Germany. A&O was one of the five London commercial firms known as the Magic Circle.

A&O also helped draft contracts used across the financial markets. With Clifford Chance, it prepared the Loan Market Association's recommended syndicated loan agreements in 1999, giving lenders and borrowers a common form to adapt. It was drafting counsel on the 2002 ISDA Master Agreement, which sets terms for derivatives transactions, including termination and default.

A&O advised the underwriters of Malaysia's US$600 million global sukuk issue in 2002, structured to comply with Islamic law, and HBOS on the United Kingdom's first covered bond the following year. The latter gave investors claims against both the bank and a pool of residential mortgages, using contractual arrangements in the absence of specific UK covered-bond legislation.

Following the financial crisis, a 2009 restructuring reduced A&O's workforce by about nine per cent. Its practice advising private individuals and families separated to form Maurice Turnor Gardner. Expansion continued in Australia, where partners recruited from Clayton Utz opened Sydney and Perth offices in 2010, and in Africa, with offices in Casablanca in 2011 and Johannesburg in 2014.

Shearman & Sterling

Shearman & Sterling was founded in New York in November 1873 by Thomas G. Shearman and John William Sterling, both formerly of David Dudley Field's practice. Shearman specialised in litigation and Sterling in corporate work. The financier Jay Gould was among the clients they brought to the partnership. National City Bank of New York, a predecessor of Citibank, retained the firm in 1891 and remained a client for more than a century. At the bank's encouragement, the firm expanded by merging with Cary & Carroll in 1919.

After the Second World War, Boykin Wright and other lawyers joined from Cahill Gordon, bringing new clients. The firm advised on German corporate and municipal debt restructuring and helped companies including BASF and Siemens resume business in the United States. Its securities work included Ford Motor Company's US$657 million initial public offering in 1956, then the largest common-stock offering in the United States.

The firm opened its first overseas office in Paris in 1963. Work for oil-producing states took it into North Africa and the Middle East. Algeria retained it in 1965 to negotiate with foreign oil companies; advice on the establishment of the Abu Dhabi National Oil Company in 1971 led to a permanent presence in Abu Dhabi. Offices in London and Hong Kong opened in 1972 and 1978 respectively, with Tokyo, Beijing and Singapore added during the next two decades.

During the Iran hostage crisis, Shearman & Sterling represented Citibank in negotiations over frozen Iranian assets that formed part of the settlement securing the hostages' release in 1981. Bank lawyers met at the firm's offices to complete the documentation for transferring funds through the Federal Reserve Bank of New York.

The firm's European offices expanded beyond US law. Emmanuel Gaillard established an international arbitration practice in 1987. The London office, which initially practised US law, recruited its first UK lawyers in 1996 to offer English-law advice. In 2000, a group of partners from Schilling, Zutt & Anschütz joined Shearman in Germany, while others joined Allen & Overy. The Mannheim office returned to independence as Schilling, Zutt & Anschütz in 2008.

Under senior partner David Beveridge, the firm opened offices in Austin and Houston in 2018 as part of an effort to expand its US corporate business, particularly in energy transactions and projects. In 2021, Gaillard and fellow arbitration head Yas Banifatemi left with six partners to establish Gaillard Banifatemi Shelbaya Disputes.

Merger

The predecessor firms' logos before their merger in 2024.

Allen & Overy had sought a larger US practice for several years, particularly in New York. Talks with O'Melveny & Myers failed in 2019. Shearman & Sterling's negotiations with Hogan Lovells ended in March 2023, amid partner departures and redundancies at Shearman.

The firms announced their proposed combination on 21 May 2023. Figures reported at the announcement put A&O's annual revenue at approximately US$2.65 billion and Shearman's at US$1 billion. Their stated rationale was to combine Shearman's US corporate client base with A&O's wider international network, bringing US, English and local-law advice into one firm. In October, more than 99 per cent of votes cast by partners at each firm supported the merger.

The merger took effect on 1 May 2024. A&O Shearman began with nearly 4,000 lawyers and 3,000 other employees in 47 offices, and combined annual revenue of approximately US$3.5 billion. A&O's Khalid Garousha became senior partner and Hervé Ekué managing partner; Shearman's Adam Hakki became co-chair of the board and executive committee and chair of the US business.

Integration and restructuring

In September 2024, A&O Shearman announced plans to cut its roughly 800-strong partnership by ten per cent, close the Johannesburg office and discontinue its consulting business. The firm said the changes would remove overlaps while allowing recruitment and promotions elsewhere. By October 2025, Legal Business reported that more than 170 partners had left or retired since the merger announcement, including 130 since completion. More than a third of the departures were in the United States.

Agreement with the Trump administration

On 11 April 2025, during the Trump administration's campaign against law firms, A&O Shearman's US practice reached an agreement with the administration to avoid potentially punitive executive action. It committed to provide US$125 million in pro bono legal services for causes supported by the administration, including assistance to veterans and combating antisemitism. The agreement also included commitments concerning employment practices and the acceptance of clients regardless of political affiliation. The administration agreed to withdraw an Equal Employment Opportunity Commission inquiry into the firm's employment practices.

The agreement prompted concerns among associates. At internal meetings later that month, the firm's leaders said that the commitment did not extend to working directly for the US government or negotiating trade agreements.

In July 2026, the United States Department of Justice subpoenaed A&O Shearman and 13 other firms in connection with the American Bar Association's lawsuit challenging the administration's actions against the legal profession. The subpoenas sought documents and testimony concerning the executive actions and agreements, including communications with Trump's adviser Boris Epshteyn.

Banking and capital markets

In 2020, the firm advised JDE Peet's and its largest selling shareholder, JAB, on the coffee company's initial public offering on Euronext Amsterdam. Pandemic restrictions required investor marketing and due diligence to be conducted remotely. The International Financial Law Review (IFLR) selected it as Equity Deal of the Year at its 2021 European awards, describing it as the first initial public offering exceeding €1 billion conducted entirely remotely.

During the transition away from the LIBOR interest-rate benchmark, the firm advised BNP Paribas and NatWest on Tesco's US$3.4 billion multicurrency credit facility in 2020. The agreement used the Sterling Overnight Index Average and the Secured Overnight Financing Rate from signing; earlier facilities had retained LIBOR initially and provided for a later switch. Tesco's borrowing margin was also linked to its performance against sustainability targets.

The firm also advised on the use of blockchain technology to issue and settle bonds. In 2019, it acted for Banco Santander on a US$20 million bond issued and settled using Ethereum. Both the bond and the cash used to purchase it were represented digitally; Santander issued the bond to another entity within its own group. The firm subsequently advised the banks on the European Investment Bank's €100 million digital bond in 2021, which used a public blockchain and was sold to institutional investors.

In 2023, it advised the Hong Kong government on an HK$800 million tokenised green bond. The transaction operated on a private network, with digital records establishing ownership and settlement taking place through Hong Kong's Central Moneymarkets Unit. The government described the issue as the first tokenised green bond issued by a government.

In December 2024, the firm advised The Nature Conservancy on Ecuador's debt-for-nature conversion supporting the Amazon Biocorridor Programme. The transaction used US$1 billion in new financing to repurchase approximately US$1.53 billion of outstanding sovereign bonds at a discount. Part of the savings on debt payments was allocated to conservation payments and an endowment. The programme was expected to provide approximately US$460 million over 17 years for conservation in the Ecuadorian Amazon.

Mergers and acquisitions

The firm's acquisition work has included transactions requiring the sale of businesses to secure competition approval. In 2016, it advised Japan's Asahi Group Holdings on the €2.55 billion acquisition of Peroni, Grolsch and Meantime, followed by a €7.3 billion agreement to acquire former SABMiller businesses in the Czech Republic, Slovakia, Poland, Hungary and Romania from AB InBev. The disposals formed part of AB InBev's commitments to the European Commission in connection with its takeover of SABMiller. The firm's regional teams handled local-law due diligence and advice on financing, competition, tax and employment. The €7.3 billion acquisition was completed in March 2017.

The firm was among the legal advisers to CVS Health on its acquisition of Aetna, announced in 2017. Valued at approximately US$69 billion, or US$77 billion including assumed debt, the transaction combined CVS's pharmacies and pharmacy-benefit management business with Aetna's health insurance operations. Both companies sold individual Medicare Part D prescription-drug plans. The US Department of Justice concluded that the acquisition would reduce competition in 22 states and required Aetna to divest that business to WellCare.

In 2025, the combined firm advised Prosus, the Amsterdam-based technology investor controlled by South Africa's Naspers, on its €4.1 billion offer for Just Eat Takeaway.com. The Amsterdam-led team included corporate, tax and employment lawyers. Competition scrutiny focused on Prosus's existing minority shareholding in rival delivery platform Delivery Hero. The European Commission cleared the acquisition subject to commitments to reduce that holding and restrict voting rights and board representation.

Projects and infrastructure

The firm advised Citadel Capital and the Egyptian Refining Company on financing the US$3.7 billion Mostorod refinery project in Egypt. Negotiations continued through the global financial crisis and the 2011 Egyptian revolution. Financing was completed in 2012, comprising US$2.6 billion in debt and US$1.1 billion in equity.

In Saudi Arabia, the firm advised Dow Chemical on the financing of Sadara, its petrochemicals joint venture with Saudi Aramco. Financing agreements for US$12.5 billion were signed in June 2013, following a US$2 billion sukuk issue. The funding combined export-credit support, commercial lending, investment from Saudi Arabia's Public Investment Fund and Islamic financing arrangements. Sadara received the US Export-Import Bank's Deal of the Year award in 2013.

The firm also advised commercial lenders and Nippon Export and Investment Insurance on the financing of Kuwait's first independent water and power project, Az-Zour North, in 2013. The project combined electricity generation with desalination, supported by a 40-year agreement for the Kuwaiti government to purchase its output.

Restructuring and insolvency

In Re Spectrum Plus Ltd (2005), the firm represented National Westminster Bank in a dispute over lenders' rights when a borrower becomes insolvent. The bank argued that its security over money owed to Spectrum Plus by customers was a fixed charge, giving it priority over certain other creditors. The House of Lords held that the security was instead a floating charge, because the company remained free to use the proceeds in its business. The decision overturned the earlier approach in Siebe Gorman & Co Ltd v Barclays Bank Ltd and clarified the degree of control needed to create a fixed charge over such debts.

Following the collapse in air travel during the COVID-19 pandemic, the firm represented Virgin Atlantic in the first restructuring plan approved under Part 26A of the Companies Act 2006, introduced by the Corporate Insolvency and Governance Act 2020. Approved by the High Court in September 2020, the plan reorganised obligations to four classes of creditors as part of a wider recapitalisation to keep the airline operating.

In Argentina's approximately US$65 billion foreign-debt restructuring in 2020, the firm advised Bank of America and HSBC, the banks managing the exchange offer, on New York law. The restructuring used collective action clauses in bonds issued from 2016, which allowed specified creditor majorities to approve changes binding on other holders. Latin Lawyer selected it as its restructuring Deal of the Year.

Arbitration and public international law

In Enka Insaat ve Sanayi AS v OOO Insurance Company Chubb, the firm represented a contractor facing proceedings in Russia following a fire at a power station. The construction contract provided for arbitration in London but did not expressly identify the law governing the arbitration agreement. In 2020, the UK Supreme Court held that English law governed that agreement and upheld an injunction restraining the Russian proceedings.

In the Yukos arbitration, the firm represented three companies holding a majority interest in the Russian oil producer Yukos. They argued that tax assessments and enforcement measures had been used to bankrupt the company and transfer its assets to the state. In 2014, the tribunal found that Russia had breached the Energy Charter Treaty and awarded the claimants more than US$50 billion. The awards led to prolonged proceedings over their validity and enforcement; in March 2026, the English High Court ruled that the shareholders could enforce them in the United Kingdom.

The firm also acted for Cuba in its challenge to Australia's tobacco plain-packaging legislation at the World Trade Organization. Cuba disputed restrictions on the use of trademarks and geographical indications on tobacco packaging. The panel rejected the claims, and its report in Cuba's dispute was adopted in August 2018 without an appeal.

In climate-related advisory proceedings, the firm represented Djibouti before the International Tribunal for the Law of the Sea and advised it in relation to proceedings before the International Court of Justice. The maritime tribunal concluded in May 2024 that human-caused greenhouse-gas emissions constituted marine pollution under the United Nations Convention on the Law of the Sea, requiring states parties to take measures to prevent, reduce and control that pollution. The ICJ's July 2025 opinion addressed the wider obligations of states under climate treaties and customary international law, including duties to prevent significant environmental harm and to cooperate in protecting the climate system.

Government and diplomacy

• Melody Barnes, director of the White House Domestic Policy Council during the Obama administration.
• James M. Beck, United States solicitor general and member of the House of Representatives.
• Laurens Jan Brinkhorst, former Dutch deputy prime minister and minister of economic affairs.
• Margery Bronster, former attorney general of Hawaii.
• Annagrazia Calabria, Italian politician.
• Joseph A. Doyle, United States assistant secretary of the Navy from 1979 to 1981.
• Michael Forrestal, National Security Council official during the Kennedy and Johnson administrations.
• Thomas Graham Jr., American diplomat and arms-control negotiator.
• Ferdinand Grapperhaus, Dutch minister of justice and security from 2017 to 2022.
• John McCarthy, Australian diplomat who served as ambassador to the United States, Indonesia and Japan, and as high commissioner to India.
• Erika Mouynes, former foreign minister of Panama.
• Caroline Mulroney, former Attorney General of Ontario.
• Stephen A. Oxman, United States assistant secretary of state for European and Canadian affairs.
• Clark Randt, United States ambassador to China from 2001 to 2009.
• Mitchell Silk, United States assistant secretary of the Treasury for international markets during the first Trump administration.
• Thomas E. Stephens, appointments secretary to President Dwight D. Eisenhower.
• Tom Suozzi, member of the United States House of Representatives from New York.
• Christopher Walford, former Lord Mayor of London.
• Garrard B. Winston, United States under secretary of the Treasury.
• David Wootton, Lord Mayor of London from 2011 to 2012.
• Stéphanie Yon-Courtin, French member of the European Parliament.

Judiciary and regulation

• Raymond Dearie, former chief judge of the United States District Court for the Eastern District of New York.
• James Donato, judge of the United States District Court for the Northern District of California.
• Elizabeth Hazlitt Emerson, former justice of the New York Supreme Court.
• Stephan Harbarth, president of Germany's Federal Constitutional Court.
• William F. Kuntz II, judge of the United States District Court for the Eastern District of New York.
• Jeffrey A. Meyer, former judge of the United States District Court for the District of Connecticut.
• Edward Murray, judge of the High Court of England and Wales.
• Sarmad Jalal Osmany, former judge of the Supreme Court of Pakistan.
• Richard Smith, judge of the High Court of England and Wales.
• Heath Tarbert, chairman of the Commodity Futures Trading Commission from 2019 to 2021.
• Joachim Wuermeling, former member of the Deutsche Bundesbank executive board and the European Parliament.

Legal practice

• Thomas F. Fennell, lawyer specialising in arbitration.
• Emmanuel Gaillard, lawyer specialising in international arbitration.
• Henry Harfield, banking lawyer specialising in letters of credit.
• Patricia Hynes, former president of the New York City Bar Association.
• Ann Olivarius, civil rights lawyer and founding partner of McAllister Olivarius.
• Thomas Wilner, lawyer who represented detainees at Guantanamo Bay.

Business

• Temi Adeniji, music executive at Warner Music Group.
• Tim Bezbatchenko, football executive and former president and general manager of the Columbus Crew.
• Keily Blair, chief executive of OnlyFans.
• Mitch Caplan, former chief executive of E-Trade.
• Philippe Dauman, president and chief executive of Viacom from 2006 to 2016.
• Chelsy Davy, founder of the jewellery brand Aya.
• Markus U. Diethelm, former general counsel of UBS and Credit Suisse.
• Gerry Fitzsimons, chief executive of TTP Ventures.
• Albert Theodore Powers, businessman who chaired Allied Pacific Group.
• Douglas W. Shorenstein, chairman and chief executive of Shorenstein Properties.
• Steuart Walton, businessman, Walmart director and co-founder of Runway Group.
• Nina Zagat, co-founder of the Zagat restaurant guides.

Academia

• John Dewar, legal academic and former vice-chancellor of La Trobe University.
• Kristine A. Huskey, clinical professor of law at the University of Arizona.
• Twinette Johnson, dean of the Saint Louis University School of Law.
• David Kershaw, professor of law and former dean of LSE Law School.
• Charles W. Mooney Jr., scholar of commercial and bankruptcy law at the University of Pennsylvania Law School.
• Frederick Mostert, intellectual property lawyer and professor of practice at King's College London.
• Robert Mundheim, former dean of the University of Pennsylvania Law School and general counsel of the United States Department of the Treasury.
• Marike Paulsson, international arbitration scholar and visiting professor at the University of Miami.
• Steven L. Schwarcz, professor of law and business at Duke University.
• Steven Davidoff Solomon, professor of law at the University of California, Berkeley.
• A. Benjamin Spencer, dean of William & Mary Law School.

Literature, media and the arts

• Ikenna Azuike, broadcaster, filmmaker and creator of What's Up Africa.
• Fernando Berckemeyer, Peruvian journalist and newspaper editor.
• Lawrence Joseph, American poet and legal academic.
• Nick Laird, Northern Irish poet and novelist.
• Geri Miller, actress associated with Andy Warhol's Factory, who later worked as a member of the firm's staff.
• William A. Rusher, publisher of National Review and political commentator.
• Bob Woodruff, journalist and former co-anchor of ABC's World News Tonight.