Cleary's Simon Jay describes how his firm has evolved its London practice since opening in the City more than 40 years ago

Cleary Gottlieb Steen & Hamilton opened its doors in London more than 40 years ago. Unlike many of its peer firms in the US, Cleary had, from its inception in 1946, been a firm with ambitions on both sides of the Atlantic. Having opened in Paris in 1949 and Brussels in 1960, the London office was thus a relative latecomer to the Cleary European presence when Manley Hudson opened its doors as the sole resident partner in 1971.

Initially the office had a distinctly American flavour. In the early days the new lawyers were primarily transferred from New York and, consistent with the regulatory environment at the time, were only able to practise US law. The London office was very much a piece of New York in the City – busy and vibrant, but small and focused on US securities advice and the US components of global M&A transactions.

Throughout the 70s and early 80s, growth was modest but, with the privatisation programme of the Thatcher Government, which was soon followed by other European countries, the volume of US securities law advice increased dramatically as European issuers sought to access the US capital markets. The office gradually increased in numbers, with further US partners and associates moving to London developing the office's reputation for complex US tax and securities law advice. It became a notable feature of the Cleary London practice that the US partners who came to London stayed in London for the long term, providing a solid base for the next stage of development of the office – the arrival of the English.

The early 90s saw changes in the regulatory framework, which transformed the London legal landscape and, to a significant extent, the international legal landscape. Once English firms became free to practise New York law, it was only a matter of time for those US firms with international ambitions to develop their own English law practices.

The Cleary English law capability commenced in London in 1997 with former Lovells partner Andrew Curran joining the firm. I became the second English London resident partner two years later. During the early days of the English practice, we were focused on M&A, financing, capital markets and related corporate work. An English tax capability was soon developed to complement the strong reputation of the existing US tax practice in London. But, throughout this development and in keeping with the firm's traditional approach, we encouraged our English lawyers not to become too narrowly focused – a strategy which has proved invaluable, given the events of recent years.

Because of Cleary's preference for organic growth, its global lockstep and full equity partnership, our approach has been one of steady but modest expansion, not seeking to rival the magic circle or even many of the more recent US arrivals in terms of size or full-service capability. But steadily, by playing to our strengths with global co-ordination on complex, cross-border transactions, the English law offering has become an integral part of the Cleary global network.

While the enactment of Sarbanes Oxley in 2002 saw a rapid decline in the volume of US-registered offerings conducted by US firms in London, changes in the global market favoured those US firms with a developed English law capability. The success of English law as the law of choice in many cross-border financing and M&A deals led to a rapid increase in the workload of our English practice. The London practice has always benefited from its close relationship with our Moscow office, and the demand for English law advice from Russia has been followed by similar demand from other emerging markets where Cleary has traditionally had a strong presence, including South America, the Middle East and Africa.

The financial crisis which struck in 2007 required all firms to re-examine the nature of their practices. Traditional M&A and capital markets transactional work gave way to restructuring, while it soon became apparent that a wholesale rewriting of the regulatory rulebook for financial institutions would take place on both sides of the Atlantic.

Strong demand for regulatory advice from financial institutions needing to navigate the often conflicting demands of Dodd Frank and the European Union legislative programme has seen many of our lawyers in London contributing to the work of our regulatory reform group. And the continuing sovereign debt crisis in Europe has seen many of them involved in the firm's representation of Greece in its recent debt restructuring.

Litigation was also understandably a major area of expansion for firms across the globe at this time. In 2009 Cleary embarked on the development of an English disputes resolution practice when Jonathan Blackman relocated from New York. His arrival was soon followed by the arrivals of Jonathan Kelly and Sunil Gadhia, who have since built a strong UK litigation capability.

Cleary's global antitrust practice has always contributed significantly to the firm's overall reputation as well as the development of its transactional practices. The firm has always had a strong English presence in the Brussels office competition team, but rapidly increasing workloads during this period required greater capacity in London. With Nicholas Levy and Romano Subiotto QC splitting their time between Brussels and London and Maurits Dolmans moving to London, the domestic competition practice also grew recently with the hire of former Competition Commission chairman Peter Freeman and Paul Gilbert, former deputy director of competition policy at the Office of Fair Trading.

Organic growth and a celebration of diversity remains very much the order of the day at Cleary. We have promoted four new English partners from the London associate ranks in the last three years and our trainee programme, which now recruits between 12 and 15 lawyers each year, will ensure that there is abundant talent to maintain growth in the future. The international background of our lawyers is clear – in London we have native speakers of 12 different languages and denizens of many other English-speaking countries.

Both in our people and the work we do, the London office of this "US firm" is very different to what would have ever been thought possible 41 years ago but has remained faithful to the principles of our founders when they set out to develop an international firm in 1946.

Simon Jay is a partner at Cleary Gottlieb Steen & Hamilton in London.