LAGOS, Nigeria (AP) — Royal Dutch Shell PLC says it will spend more than $2 billion in the coming years to cut down on gas flaring in Nigeria's oil-rich delta.

Shell announced Wednesday that its project would involve 26 flow stations in the Niger Delta, in areas where the oil major had seen its work stopped by funding shortages or security concerns.

Shell says its Nigerian subsidiary already spent more than $3 billion to install such equipment at 32 flow stations.

Gas flaring is the burning of natural gas that is produced along with crude oil. Environmentalists describe it as one of the largest sources of greenhouse gases, which cause global warming.