John Ahern is a Non-contentious Financial Services Regulatory Partner in the Financial Markets & Products Group.

With more than 30 years of experience in UK, European, and Asian financial markets, John advises banks, multilateral trading facilities, broker-dealers, asset managers, and investment advisors on regulatory challenges. He offers clients who are active in the transport, energy and infrastructure sectors deep knowledge of how regulators in different jurisdictions approach compliance and enforcement issues and helps them operate in compliance with financial regulations, while also maximizing opportunities.

John’s practice focuses on the regulation of banks and other financial institutions by the EU and UK prudential and conduct regulators. He regularly advises on various EU regulations that were developed in the aftermath of the 2008 financial crisis, including MiFID II, the Market Abuse Directive II, the Payment Services Directive II, the Capital Requirements Directive, and the EU’s EMIR regulation in relation to futures and derivatives. He has a particular focus on prudential regulation of banks and investment firms and frequently advises on the Capital Requirements Regulation and related regulatory measures.

John’s practice also involves advice to asset management and private fund clients on AIFMD, custody arrangements, brokerage, clearing and trading, and payment systems. John also has experience representing individuals in UK Financial Conduct Authority (FCA) compliance and enforcement matters.

John previously served for eight years as in-house counsel for a global investment bank, and he draws on this understanding of financial business operations in advising clients.

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  • Represented a major Asian bank in the establishment of a private wealth business in the UK.
  • Advised a European proprietary trader on establishing a UK subsidiary and the capital requirements associated with it.
  • Represented an international banking group in the acquisition of certain assets and liabilities from The Royal Bank of Scotland relating to its structured retail investor products and equity derivatives business.
  • Advised a leading UK commercial bank with a corporate governance review project. Provided advice on the bank's compliance with corporate governance obligations under the Companies Act 2006 and as a PRA- and FCA-regulated entity.
  • Advised UK commercial banks on the portfolio reconciliation and dispute resolution obligations imposed by EMIR.


  1. 1995 · Admitted in England & Wales
  2. 1993 · Admitted in the Republic of Ireland
  3. 1986 · National University of Ireland, BCL, Law

memberships and associations

  1. Law Society of England & Wales
  2. Law Society of Ireland Pro Bono Program