Top 50 US Firms in London Rank:24Revenue:$138.9No. of Partners:17The Lawyer research data

New York firm Sullivan & Cromwell is characterised by its ‘generalist’ approach to legal services, a style that might on the face of it sound somewhat downmarket but in reality is anything but. Sullivan & Cromwell, one of the world’s most profitable law firms, has long sat right at the top of the legal market, scoring a succession of mandates on the world’s biggest M&A, disputes, banking deals and governmental matters. Indeed Sullivan & Cromwell’s close links to the centre

New York firm Sullivan & Cromwell is characterised by its ‘generalist’ approach to legal services, a style that might on the face of it sound somewhat downmarket but in reality is anything but. Sullivan & Cromwell, one of the world’s most profitable law firms, has long sat right at the top of the legal market, scoring a succession of mandates on the world’s biggest M&A, disputes, banking deals and governmental matters.

Indeed Sullivan & Cromwell’s close links to the centre of US governmental power were underlined when a number of its lawyers, notably Jay Clayton, who became chairman of the SEC, joined President Trump’s administration.

Despite its success, Sullivan & Cromwell is also generally thought of as being among the most conservative – staid, even – of the top US firms, both in terms of style and growth strategy. It rarely hires laterally and also eschews bureaucracy, with the lawyers on its management committee also expected to put in a full-time fee-earning stint each year.

The firm was founded by Algernon Sydney Sullivan and William Nelson Cromwell in 1879 and continues to be run along traditional, all equity, single profit pool lines, with transformative cross-border mergers noticeably absent. Sullivan & Cromwell entered the London market in 1972 and its City office is now its second largest after New York.