UPDATE 1-Shell declares force majeure on Nigeria Bonny Light oil

LONDON/ABUJA, March 5 (Reuters) - Royal Dutch Shell declared force majeure on the Nigerian Bonny Light crude oil grade on Tuesday due to a leak on a pipeline, a day after warning it may need to close the line altogether because of oil theft.

Shell Petroleum Development Company (SPDC) declared the force majeure on the Bonny Light offtake programme at 1500 GMT following the shutdown of Nembe Creek Trunkline after a leak was observed on Sunday, Shell said in a statement.

Shell's country head warned on Monday that it may be forced to completely shut down the 150,000 barrel per day Nembe Creek pipeline because of "unprecedented" levels of theft.

SPDC is a joint venture with the Nigerian state oil firm NNPC holding 55 percent, Shell 30 percent, Total 10 percent and Eni 5 percent. Shell operates production.

"There has been a recent upsurge in crude theft activities on NCTL, resulting in frequent production shutdown and massive oil spills blighting the environment," the statement said.

It said that between Feb. 22-25, flow stations feeding into the pipeline were shut down by safety systems three times due to oil theft.

"The leak on Sunday occurred directly on the NCTL and necessitated its immediate shut down for repairs," the statement said, adding that the cause would be determined by a joint investigation visit.

Nigeria was due to export 168,000 barrels per day of Bonny Light in March before this outage, according to shipping programmes.

The Nembe trunkline is one of the most important production routes for Africa's top crude oil exporter, feeding the benchmark Bonny Light export terminal.

The pipeline was replaced in 2010 at a cost of $1.1 billion, Shell says.