BP said on Thursday it had started production at the Platina oilfield offshore Angola, helping Africa's second biggest oil exporter slow a decline in output.

The Platina field will be linked to BP's existing Greater Plutonio floating production, storage and offloading (FPSO) system in Angola's Block 18 which started up in 2007.

It will produce 30,000 barrels of oil per day at its peak and access an estimated 44 million barrels of oil reserves.

The project was delivered 44 days ahead of schedule and 25% below the original budget, BP said in a statement.

The new production will help the West African nation slow a decline in output after years of lower investments in the sector.

BP, which is the operator of the field, has a 46% stake in Block 18. China's Sinopec has a 37.72% stake and Angola's national oil company Sonangol the remaining 16.28%.

(Reporting by Ron Bousso; Editing by Jan Harvey and Alexander Smith)