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John Ahern

Work +44 (0) 20 7770 5253

Work Department

Financial Services


John Ahern, partner at Katten Muchin Rosenman UK LLP and head of the London Financial Services group, focuses his practice on banking and financial services regulation with a strong focus on the UK and European financial markets and related regulations. His background in private practice and as in-house counsel at a global investment bank provides him with a perspective on the unique regulatory issues facing the wholesale and private banking sectors. John advises multilateral trading facilities, broker-dealers and banks on trading, clearing and settlement as well as client money and custody of securities—both physical and dematerialized. He has a particular focus on regulatory capital, and advises a number of banks and other authorized firms on the requirements and implications of the prudential regime. John counsels asset managers and investment advisors on the regulation of alternative funds in Europe.

John assists clients in navigating the regulatory system and counsels them in documenting a range of customer relationships, including the preparation of client agreements, inter-group arrangements, trading platform rulebooks and related compliance documentation.

John is a frequent speaker at seminars and conferences and has written a number of articles for well-respected publications on financial services regulations.

London: Corporate and commercial

Financial services: non-contentious/regulatory

Within: Financial services: non-contentious/regulatory

Katten's experienced finance and regulatory team works across its US, London and Shanghai offices, representing a range of financial institutions, including banks, financial holding companies and investment funds. John Ahern leads the London financial services group and focuses on banking and financial services regulation. Also notable for the firm in this area are Nathaniel Lalone, Neil Robson, Carolyn Jackson and David Brennand.

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London: Finance

Derivatives (including commodities)

Within: Derivatives (including commodities)

The London office of Katten is part of the firm's transatlantic practice, which advises on regulatory, compliance, transactional, documentation and structural matters. The firm is adept at futures, cleared and uncleared swaps, including their use in structured products. Among its clients are investment firms, including broker-dealers; end users such as proprietary trading groups, hedge funds, commodity pools, pension  plans, corporations and municipalities; clearinghouses, exchanges, multilateral trading facilities and swap execution facilities. It also works with intermediaries; clearing firms; alternative investment fund managers; and swap dealers in the US and EU. Regulatory expert John Ahern joined from Jones Day in early 2018 to lead the financial services practice.  Carolyn Jackson provides US financial regulatory legal advice to commercial banks, investment banks, trade associations and OTC derivatives service providers. Nathaniel Lalone and Neil Robson are also recommended for regulatory and compliance advice.

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