INTERVIEW-IEA sees further slide in energy investments

* IEA will revise investment projections downwards

* More detailed IEA energy outlook to be released in Nov

PARIS, June 23 - Recession will cut investments in the energy supply sector in 2009 by more than the $100 billion quoted in the International Energy Agency's report released in May, its chief economist said on Tuesday.

The agency, adviser to 28 industrialised countries, said in a report presented to the G8 energy ministers in May that oil and gas upstream investment would fall 21 percent, or about $100 billion in 2009 from 2008 due to the global recession.

"The information that we are getting... may well mean that we are going to revise the numbers downwards," Fatih Birol told Reuters in an interview.

Birol said the IEA had not made a comprehensive update of the G8 report but that the agency was getting signals the drop in investment would be worse than initially feared.

A more detailed update will be released for the IEA world energy outlook in November, he added.

Birol cited three reasons for the worse-than-feared decline in investments.

"The first thing is that the oil price prospect is still uncertain with most companies not having yet increased their price assumption to base their projects from $40-45," he said.

He cited as other reasons the fact firms did not foresee demand picking up, and that key producing countries still had some spare capacity to be used.

"For those reasons I think it would be wrong to say that the investment appetite of the oil companies has returned," he said.

Asked whether $75 a barrel, a price branded by Saudi Arabia as a target, would be fair for consumers and producers, Birol said: "In a normal world, when the global economy is running in order,..., to bring new investments in the offshore and oil sands to the market, you need a price level of $75 a barrel."

But in the current economic context, any strong price rise from the current price of $68 a barrel would hurt the economic recovery, Birol said.