Rowe & Maw is losing a top lawyer to Aquila Energy.
Carole Colley, a 10-year US and UK dual-qualified lawyer, will leave Rowe & Maw's projects and banking group where she is a senior assistant at the end of February to take up her new post on 13 March.
She will join Aquila Energy's in-house department as director of legal and regulatory affairs.
In Europe, Aquila Energy, a subsidiary of US-based UtiliCorp United, which last year recorded sales of $18.6bn (£11.6bn), is a leading independent provider of risk management, transportation, gas supply and balancing services to retail gas supply companies.
In addition to London, the company has European bases in Spain, Norway and Germany with plans to open further offices.
Colley's role will be to manage its UK and European energy contracts and manage the company's legal affairs across Europe. This will involve coordinating the company's outsourcing requirements throughout Europe, which may include setting up a formal panel.
Colley has previously worked with US-based international corporate practice Bryan Cave.
Neil Morrison, Rowe & Maw's head of projects and banking, says: "We do have replacements lined up."