Central African leaders officially opened the taps Saturday on one of the largest private investments in sub-Saharan Africa - a 663-mile, $3.7 billion pipeline snaking from Chad through virgin rain forests to the Atlantic.
The presidents of landlocked Chad and the coastal nation of Cameroon took turns opening two pumping station valves before a gathering of leaders of other African nations - including some equally caught up in a regional oil boom.
Supporters say the project will bring billions of dollars and tens of thousands of jobs to the two countries. Opponents say the project threatens to pollute farmland and feeds corruption.
Crude began flowing through the pipeline last year, but a spat between presidents Paul Biya of Cameroon and Idriss Deby of Chad delayed the formal inauguration until Saturday.
Biya called the opening of the pipeline a "victory over skepticism." The Cameroon leader asked for "comprehension and hospitality" from the people through whose homelands, villages and towns the pipeline runs.
Oil companies ExxonMobil, Chevron and Malaysia's Petronas financed the massive project, with the World Bank providing 4 percent of the funding and its imprimatur to the potentially risky and already controversial project.
The World Bank has committed to monitoring dispersal of profits from the project, hoping to make it a model development program.
But opponents say the project threatens vital farmland in Chad, and is disrupting communities including those of pygmies in Cameroon, who were given cash compensation for the pipeline routing through their traditional hunting grounds.
"The Chad-Cameroon pipeline, in fact, is far from improving the quality of life for the populations ... of the two countries concerned," Cameroon's private Center for the Environment and Development said in a statement Saturday.
The group urged the oil giants involved to increase environmental safeguards at the pipeline and do more to compensate populations disrupted by the pipeline and the flood of oil workers.
On Saturday, ExxonMobil vice president Frank Risch pledged "environmental protection with U.S. and European standards applied."
Risch said ExxonMobil and its partners in the project already had employed 35,000 people, 65 percent of them from Chad and Cameroon, and laid 370 miles of roads in the two countries.
The World Bank's Cameroon representative, Madani Tall, said the international lender agreed to take part only because the companies involved agreed to adhere strictly to environmental norms, and because Chad pledged to use the profits for its impoverished people.
Tall stressed "the need for vigilance" in seeing that all the promises were fulfilled.
Risch said production was expected to reach its target of 250,000 barrels per day within weeks, a level at which it is to continue for 25 years. The pipeline already produces about 180,000 barrels per day.
Total receipts are estimated to reach at least $12 billion over the life of the project, with Chad receiving 12.5 percent of that. Cameroon is slated to receive a smaller share.
West Africa is one of the world's fastest increasing oil regions, with production projected to provide 25 percent of U.S. oil imports alone by 2010.
Nigeria, the world's seventh-biggest oil exporter and the source of one-fifth of U.S. oil imports, produces 2.5 million barrels a day.
Chad and Cameroon both are cited by Amnesty International and other rights groups for alleged human rights violations, while Transparency International ranks Cameroon as among the world's top-five most corrupt governments.
Leaders of Central African Republic, Burkina Faso and Equatorial Guinea were on hand for Saturday's ceremony. Four dozen traditional dance groups performed, in a ceremony and banquet stretching over five hours.