Yar'Adua promised when he took office just over a year ago to declare a national emergency on power but has since said he is waiting for two committees, set up to investigate mismanagement by his predecessor, to report back first.

The power crisis has become so severe that much of the country has been without mains electricity for weeks, plunging neighbourhoods without private generators into darkness every night and heightening frustration among its 140 million people.

"Next month I am going to declare a national emergency in the power sector," he told a gathering of French businessmen.

Despite being the world's eighth-biggest oil producer, Nigeria has a generation capacity of about 3,000 megawatts (MW). South Africa, with a third of the population, has more than 10 times that capacity.

Yar'Adua said last month that the emergency period would last until the country was able to generate about 10,000 MW of electricity, which he expected to take until 2011.

Yar'Adua said on Friday the Nigerian state would invest $5 billion in the power sector over the next three years.

Nigeria was also talking to foreign sovereign wealth funds about providing cash for joint ventures in the oil sector. He mentioned Dubai's as one fund his country was in touch with.