At 1075km in length the pipeline flows from landlocked Chad to the Atlantic ports of Cameroon and represents the World Bank's largest-ever investment in sub-Saharan Africa.

Chad and Cameroon originally signed a treaty for the construction of the pipeline in 1996 with construction beginning in 2000, and now the first 950,000 barrels have left the Cameroon port of Kribi for world markets.

The project included development of 300 wells in the Doba oilfield in southern Chad, which is estimated to hold reserves of more than 900 million barrels.

Project sponsors say that revenues could reach $US2 billion for Chad and $US500 million for Cameroon over the projected 25-year production period.

Leaders from the impoverished African countries have pledged to invest the majority of expected oil revenues in programs to end poverty and to develop crucial social services such as the health, educational, and agricultural sectors.

ExxonMobil holds a 40% stake in the project, with Malaysia's Petronas holding 35% and ChevronTexaco 25%.

Hopeful of lessening its dependence on Middle Eastern oil, the United States has backed the development of West African oil fields since 1996.

The massive US demand for oil, about 19 million barrels daily, is set to be partially met by several other West African countries like Chad, Congo-Brazzaville, Equatorial Guinea and Sao Tome and Principe, all emerging as new and potentially strong oil producers.

Africa already supplies the United States with about one-fifth of its oil, roughly equal to Saudi Arabia's share of the US market.