Aggreko has poached British Gas boss Chris Weston to lead the firm after its leader Rupert Soames left the group to join embattled security firm G4S.
British Gas and Aggreko revealed in separate statements that Weston, who was one of the three most senior people at energy group, would be leaving after less than a year in his role at the Big Six firm.
"Aggreko is a fascinating business and I'm very excited to be taking on this role," said Weston.
"I have watched and admired Aggreko's tremendous growth over recent years and I look forward to working with Carole Cran and the entire management team to develop the company further in the coming years."
Aggreko is a FTSE100 support services company and world's largest temporary power generation and temperature control services business.
Cran, currently Interim CFO, has also been officially appointed as chief financial officer and executive director of Aggreko and will join the Board with immediate effect. Cran joined Aggreko in 2004 and has worked closely with Angus Cockburn as group financial controller and more recently as Director of Finance.
"I am delighted to welcome Weston to Aggreko on behalf of all the Board and the Company. Weston brings senior experience of the energy industry and proven leadership skills in a large international business," said Ken Hanna, Chairman of Aggreko.
"He has consistently succeeded in driving performance and growth in his career and we believe he has the skills and vision to continue Aggreko's growth and lead the Group to the next level.
"In addition I would like to thank Angus Cockburn so much for the immense contribution he has made to Aggreko over the last 14 years. We can understand his desire to seek a fresh challenge and wish him every success in his future career."
Weston is subject to 12 months' notice and a further announcement will be made in due course regarding the timing of Chris' departure and succession for the leadership of Centrica's International Downstream business.
He is expected to join Aggreko next year once he has completed his commitments at Centrica.
Cockburn, Aggreko's Interim CEO, will continue this role. Cockburn had previously indicated to the Board that he had decided not to apply for the role on a permanent basis and that, after 14 years at Aggreko principally as CFO, he was keen to seek fresh challenges.
Accordingly, he will step down from the Group later in the year.
Weston was tipped to replaced Centrica, British Gas' parent group, CEO Sam Laidlaw eventually.
"Weston has made an important contribution to Centrica over 11 years, leading a number of our businesses, in the UK and North America. We will be sorry to see him leave but recognise that Aggreko offers a great opportunity for him," said Laidlaw.
Centrica has recently its finance director lost Nick Luff after he announced his resignation in January.