Barry O'Leary

Mark Fennessy is the co-head of the London Finance, Restructuring and Special Situations Group. He focuses his practice on contentious and non-contentious restructuring and insolvency matters. He has particular experience in multifaceted group collapses and global insolvency issues. He has been involved in a number of high-profile assignments for banks, funds and various strategic parties. Mark leads a team with unrivalled expertise in special situations, including in relation to assets facin...

Rohan Massey is a top attorney recognized by Best Lawyers in the practice area(s) of Privacy and Data Protection Law. Rohan, who practices law in London, United Kingdom, has been recognized since 2024. This recognition is based on an exhaustive peer-review survey, reflecting the high esteem in which Rohan is held by other top lawyers in the same geographic and legal practice area.

Josh Dambacher is a top attorney recognized by Best Lawyers in the practice area(s) of Investment Funds. Josh, who practices law in London, United Kingdom, has been recognized since 2021. This recognition is based on an exhaustive peer-review survey, reflecting the high esteem in which Josh is held by other top lawyers in the same geographic and legal practice area.

Brenda Coleman specialises in all aspects of corporate tax including private equity, fund formation, public and private M&A, restructurings, complex financings and tax disputes. Her experience includes acting for private equity funds, multi-asset managers, LPs, multinational companies, banks, hedge funds, Sovereign wealth funds and various UK Government departments. Brenda is described in Chambers UK 2022 as “extremely capable, very analytical and very thorough.” Clients say &...

Marian heads the UK insurance and disputes practices working closely with the firm’s established trade and export finance team, and U.S.-based disputes team, offering advice on insurance, risk management and commercial dispute resolution.With over 20 years' experience, Marian advises banks, insurance brokers, investment funds, government agencies and corporates on commercial insurance arrangements which support structured trade, commodity and pre-export financing as well as corporate fi...

Lord Grabiner is a commercial lawyer with a substantial court, arbitration and advisory practice. For over 40 years he has been involved in many of the highest profile commercial disputes that have been fought in London. Specialising in banking & finance, energy/oil and gas, civil fraud, competition and merger investigations and shareholder disputes, Lord Grabiner is highly experienced both as an advocate in the High Court and as arbitration counsel. He also sits as an arbitrator in domes...

Al Gourley is a Partner at the firm’s London office. He is a globally-recognised resource lawyer, having led many UK and Canadian initial public offerings, secondary and alternative finance transactions, as well as mergers and acquisitions, in the resource sector, particularly cross-border transactions involving Europe, Africa, Australia and Canada. Al is also the Chairman of the World Initiative of Mining Lawyers based in Europe. Al is known for his knowledge of “pure” mini...

Graham Iversen focuses his practice on corporate tax matters, including mergers and acquisitions, private equity transactions, joint ventures, partnerships, corporate restructurings, debt and equity finance, derivatives, structured investments, real estate and tax disputes. Graham joined the firm from Slaughter and May in London, where he was a partner in the firm’s London office in their tax department for more than 14 years. He has been a corporate tax attorney for more than 22 years,...

Stephen A. Thierbach is a US-qualified corporate partner in the London office of Gibson, Dunn & Crutcher. A senior U.S. securities lawyer, he advises issuers, underwriters and selling shareholders on complex, innovative and multi-jurisdictional offerings of equity, equity-related and debt securities. He has a broad capital markets transactions practice, with a focus on initial public offerings and secondary offerings, and has represented corporates, investment banks, private equity firms ...

Patrick Doris is a partner in Gibson Dunn’s Dispute Resolution Group in London, where he specialises in global white-collar investigations, commercial litigation and complex compliance advisory matters. Mr. Doris’ practice covers a wide range of disputes, including white-collar crime, internal and regulatory investigations, transnational litigation, class actions, contentious antitrust matters and administrative law challenges against governmental decision-making. Mr. Doris handle...