A&O Shearman

Born of the 2024 merger of U.K.-based Allen & Overy and U.S.-based Shearman & Sterling, the new Allen Overy Shearman Sterling—more commonly known as A&O Shearman—has nearly 4,000 lawyers across 47 offices in 28 countries with approximately 650 attorneys reporting to a U.S. office.

Both Sides of the Pond

Allen & Overy’s history goes back to 1930, when the firm was founded in London. Over the following decades, A&O became one of London’s most prominent legal shops and expanded internationally. Founded in New York City over 150 years ago, Shearman & Sterling forged relationships with Wall Street powerhouse clients from the start. A&O Shearman builds on the significant global reach, rosters of well-known clients, and international prestige that Allen & Overy and Shearman & Sterling both bring to the new global legal force.

Global Coverage

A&O Shearman’s comprehensive lineup of practices include practices at the center of macro global trends, such as energy transition, technology, and private capital. Allen & Overy and Shearman & Sterling regularly ranked in Vault’s Project Finance, Banking & Financial Services, and Securities/Capital Markets rankings; Allen & Overy ranked in Vault’s International and Energy, Oil, & Gas rankings, as well. Combined, the firms that compose A&O Shearman had 122 Band 1 Chambers practices around the world.

The firm touts its combined reputation for unwavering commitment to delivering quality and promises to build an unparalleled firm with a forward-looking approach to deliver excellence and innovation for clients’ most complex matters.

• Advised Paramount Global in connection with the collapse of Archegos Capital Management, one of the largest recent securities class actions, earning recognition as Am Law Litigator of the Week. 
• Advised Texas Instruments, a global semiconductor company, on its definitive agreement to acquire Silicon Labs, a leader in secure, intelligent wireless technology, for approximately $7.5 billion enterprise value.
• As transaction counsel, advised the DOT on the development of the $11 billion SR 400 Express Lanes Project, working on diligence of design-build contracting arrangements and various state support contributions. This Georgia DOT’s Major Mobility Investment Program will add two express lanes in each direction along a vital corridor. It involves the largest Transportation Infrastructure Finance and Innovation Act loan in history ($3.9 billion) and private activity bonds secured by toll revenues.  
• Advised stakeholders on the arrangement and primary syndication of senior unsecured bridge credit facilities for Ferrero International S.A to finance its acquisition of WK Kellogg Co for $23.00 per share in cash, representing a $3.1 billion enterprise value.

•  White Collar Practice Group of the Year, 2025—Law360
• 316 practice area rankings worldwide, 2026—Chambers Global Legal Guide; 137 practice and individual rankings, 2025—Chambers USA: America’s Leading Lawyers for Business
• 73 practice and individual rankings, 2025—Legal 500 United States
• ESG Law Firm of the Year, Deal of the Year Awards, 2024—LatinFinance
• For a DOT project, named North America Transport Deal of the Year, 2025—Proximo; P3 Deal of the Year, 2025—The Bond Buyer; Americas Infrastructure Deal of the Year, 2025—PFI; P3 Innovation Award, 2025—The American Road and Transportation Builders Association; and Transport Deal of the Year, North America, 2025—IJGlobal