Jonathan Porteous

George Knighton is a top attorney recognized by Best Lawyers in the practice area(s) of Mergers and Acquisitions Law and Private Equity Law. George, 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 George is held by other top lawyers in the same geographic and legal practice area.

Sunay Radia focuses his practice on financial restructuring transactions, including high yield bond and LBO workouts, refinancings, consensual and nonconsensual restructurings, enforcements and distressed asset sales. He has advised on a number of complex cross border matters for creditors (including direct lenders and distressed debt funds) and sponsors. Sunay also has a wealth of experience in origination banking and finance matters, including acquisition finance and real estate finance tra...

Jason Hambury is a top attorney recognized by Best Lawyers in the practice area(s) of Construction Law and International Arbitration. Jason, 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 Jason is held by other top lawyers in the same geographic and legal practice area.

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 ...

Tony Horspool is a top attorney recognized by Best Lawyers in the practice area(s) of Insolvency and Restructuring Law. Tony, who practices law in London, United Kingdom, has been recognized since 2014. This recognition is based on an exhaustive peer-review survey, reflecting the high esteem in which Tony is held by other top lawyers in the same geographic and legal practice area.

Penny Madden is an English qualified Queen’s Counsel and serves as Co-Partner-in-Charge of the London office at Gibson, Dunn & Crutcher. She is Co-Chair of the International Arbitration Practice Group and a member of the firm’s Transnational Litigation Practice Group. She has a wide range of experience in all key aspects of international arbitration with particular expertise in shareholder, telecommunications, SPA, energy, international trade and insurance disputes. She repres...

Graham Tyler leads the firm’s Asset Finance team globally. A recognised authority on aircraft finance and leasing, Graham regularly represents financial institutions, leasing companies, equity investors, airlines and arrangers in the procurement, financing and leasing of new and used aircraft and engines and aircraft portfolio acquisitions, financings and sales. Adept at crafting complex cross-border leasing and innovative financing structures, Graham negotiates commercial debt deals in...

Vincent Zabielski focuses on international nuclear energy matters, including providing strategic advice related to new-build EPC contracts, power purchase agreements, operation and maintenance, fuel supply chain, liability issues, and export controls. Prior to joining Pillsbury, Vincent was Senior Nuclear Counsel for the UAE nuclear new build program, where he was responsible for integration of nuclear licensing strategy with the largest-ever public financing of a public works project. During...

Gillian Sproul is a top attorney recognized by Best Lawyers in the practice area(s) of Competition Law. Gillian, who practices law in London, United Kingdom, has been recognized since 2025. This recognition is based on an exhaustive peer-review survey, reflecting the high esteem in which Gillian is held by other top lawyers in the same geographic and legal practice area.