Claire Williams

Claire Williams is a Partner in the Firm’s Credit Practice, based in the London office and concentrating on infrastructure debt finance matters. She represents financial sponsors and their portfolio companies on complex cross-border financings across a wide range of infrastructure asset classes (including energy and energy transition, regulated utilities, transport and digital infrastructure). Claire has extensive experience on senior and subordinated financing structures for acquisition (including public-to-private), capex roll-out/development and refinancing transactions and regularly advises clients on multi-source and rated debt raisings.

Claire’s recent work highlights include advising:

• KKR Infrastructure in connection with financing for:
  • its voluntary tender offer to acquire Greenvolt 
  • its takeover offer to acquire ContourGlobal 
  • its takeover offer to acquire Ocean Yield A/S
  • its takeover offer to acquire Quantafuel
• Blackstone Infrastructure in connection with:
  • financing its voluntary tender offer to acquire Atlantia S.p.A. (now Mundys)
  • a sustainability-linked holdco financing relating to its investment in Mundys S.p.A.
• John Laing in connection with: 
  • the refinancing and upsize of its existing platform NAV facilities
  • financing the acquisition of a portfolio of assets from AMP Capital’s Irish Infrastructure Fund
• Viridor in connection with: 
  • implementation of its corporate level financing arrangements
  • its first investment grade rated multi-source financing structure to refinance existing debt in its EfW business
  • a greenfield financing for the construction and development of an EfW plant in Tilbury Docks
• ContourGlobal in connection with: 
  • a platform refinancing for its European renewable power generation business
  •  the refinancing of a portfolio of CHP cogeneration plants in Mexico
• Greenvolt in connection with capex facilities to finance its European utility-scale pipeline
• DigitalBridge Group, Inc. and its portfolio company, Netomnia, in its merger between Netomnia and Brsk 
• A Blackrock-led consortium in connection with partial refinancings of an acquisition bridge facility for their investment in Aramco’s Gas Pipelines
• EQT in connection with financing for its acquisition of Statera Energy 
• Q-Park in connection with a senior secured note issuance and amend and extend of its existing super senior revolving credit facility 

Claire was named a “Next Generation Partner” by Legal500 in its 2025 guide and an “Up and Coming Partner” by Chambers UK in its 2025 guide. She was also named a “Rising Star of Legal Services” by Financial News and a “UK Female Rising Star” by Law.com International in 2023. 

Prior to joining Simpson Thacher, Claire was a senior associate in a magic circle law firm in London and spent time on secondment to 3i Infrastructure.

Claire's experience prior to Simpson Thacher included representing:

• A consortium of Blackrock, Goldman Sachs and Mubadala in connection with the take private of Calisen plc
• Global Infrastructure Partners in connection with a refinancing for Edinburgh Airport
• Macquarie in connection with its acquisition of Currenta
• A consortium of Allianz and Macquarie in connection with their acquisition of Elenia
• A consortium of Macquarie and Danish pension funds in connection with their takeover offer for TDC
• A consortium led by Macquarie and CIC Capital in connection with the acquisition of a majority stake in National Grid's gas distribution business
• 3i Infrastructure in connection with:
  • a refinancing for the Wireless Infrastructure Group
  • various institutional debt raisings for Scandlines
  • the refinancing of Belfast City Airport
• InfraCapital in connection with the acquisition and refinancing of Energetics
• Antin in connection with a refinancing and bolt-on acquisitions for Eurofiber