The British Gas executive responsible for delivering price rises to millions of UK customers is quitting to join Barratt Developments as its new chief executive.
Mark Clare, who has been managing director of British Gas's residential energy business since 2002, will join the homebuilder in September.
Owner Centrica revealed in February that British Gas made losses of £75 million in the second half of 2005, after price rises failed to offset the impact of rising wholesale costs.
Centrica chief executive Sir Roy Gardner paid tribute to Mr Clare's efforts in steering the business through "a period of unprecedented wholesale and retail price volatility".
He added that he recognised Mr Clare's desire to move in order to take up a chief executive's role at another company.
Sir Roy said: "Mark has made a substantial contribution to the group, both in its early days of turnaround and growth, and more recently in transforming the UK residential energy business."
Mr Clare, who is 48, will take on the role at Barratt currently held by David Pretty, who is to retire at the end of the year after 16 years as a board director, including almost four years as chief executive.
Barratt chairman Charles Toner said Mr Pretty left the business well placed after successive years of record growth in volumes and profits.
He added: "The board is delighted to have secured someone of the calibre of Mark Clare as its group chief executive.
"His outstanding track record and experience as a FTSE 100 managing director, combined with the very strong Barratt management team he inherits, give us an exceptional blend of skills inside the board."
Mr Clare joined British Gas in 1994, becoming Centrica's finance director in 1997.
Centrica said its incoming chief executive, Sam Laidlaw - the oil executive who joins from from Chevron - would review the organisation and make an announcement as soon as possible on the future leadership of the British Gas residential arm. Mr Laidlaw is due to start on July 1.