Royal Dutch Shell said it started operations at the third phase of operations in the deep waters off the coast of OPEC-member Nigeria.

Shell said its Nigerian exploration and production company started production at the third phase of the offshore Bonga prospect.

"This new start-up is another important milestone for Bonga, adding valuable new production to this major facility," upstream director Andrew Brown said in a statement.

Shell last year started oil production from the deepwater Bonga North West development off the coast of Nigeria. At its peak, the company said the third phase of operations offshore Nigeria should be around 50,000 barrels of oil equivalent.

Nigeria was among the member states contributing most to the production from Organization of Petroleum Exporting Countries. In August, the last full month for which data are available from OPEC, Nigeria produced about 1.86 million barrels of oil per day, about 4 percent higher than the previous month.

Reserves taken from the third phase of the Bonga prospect will be fed through existing production infrastructure offshore, which can produce more than 200,000 barrels of oil and 150 million cubic feet of natural gas per day at full capacity.

The entire Bonga prospect started oil and gas production in 2005 and was Nigeria's first development in deep waters. To date, the full project has produced more than 600 million barrels of oil.

"The country's deep-water resources are making an important contribution to meeting growing energy demand in Nigeria and around the world,Tony Attah, managing director of Shell's regional exploration subsidiary, said in a statement.