The diversified energy giant said this morning that Fraser, who joined AGL in 1984 and most recently worked as group general manager, would take over as managing director and chief executive immediately.

AGL announced a profit downgrade of 17% last week only two months after the company had said 2008 profit would be at the upper end of its forecast range.

The announcement prompted AGL’s shares to plunge 20% - its biggest share slump in 20 years.

AGL’s chairman Mark Johnson said the company believed it would benefit from a new management approach.

“Paul Anthony has secured many achievements at AGL and has established a firm base on which to build our growth and integration strategy,” he said.

“However, the circumstances leading up to and surrounding the revised earnings guidance announced last week and other factors, have contributed to the directors’ view that now is the right time for a new management approach, with strengthened focus on our core operations.”

Johnson added that the board believed Fraser was the right man for the job.

“He has extensive energy industry experience, is highly respected by his peers and has a deep operational working knowledge of the company,” he said.

“Michael Fraser has been a significant contributor to the development of the company’s strategy and is committed to further developing AGL as a world-class, customer-focused energy company.”

In his previous role as group general manager Merchant Energy, Fraser led the expansion of AGL’s upstream energy interests.

He also had responsibility for AGL’s power generation, wholesale gas and electricity trading portfolios and energy sales to major customers.

Before joining AGL, Fraser worked for a chartered accounting firm and the Australian Taxation Office.

He is also a director of Queensland Gas Company and deputy chairman of ActewAGL.