Nigeria's parliament has begun a detailed debate of the latest version of long-delayed reforms to Africa's biggest energy industry, just two months ahead of elections, the head of the state oil company said on Wednesday.

The Managing Director of NNPC, Austin Oniwon, said the Petroleum Industry Bill (PIB), which will redefine Nigeria's relationship with foreign oil firms, would be put under scrutiny by both houses of parliament in the coming days.

The Senate will begin today the clause by clause debate of the bill and in the next days the House of Representatives will also start a clause by clause debate, Oniwon said at an industry conference in the capital Abuja.

President Goodluck Jonathan has vowed that the bill will become law before the end of the current administration in May and his energy adviser went further on Tuesday, saying it would be passed within weeks.

But the ambitious reforms have been subject to numerous delays and amendments, making the details of the final draft unclear. Oil executives have said billions of dollars of investment are on hold until there is clarity.

The government hopes the bill will tackle issues including funding shortfalls at its joint ventures with foreign firms, insecurity in the Niger Delta, increasing local involvement in the industry and production of more gas for domestic power.