Italian energy major ENI said on Saturday it had suspended its activities in Bayelsa state in southern Nigeria due to frequent thefts from pipelines.
"The decision was taken due to an intensification of bunkering activities, or sabotage of the pipelines," the company said in a statement.
ENI said it had completely suspended all onshore activity at the Swamp Area site in Bayelsa in the night between Thursday and Friday.
The company said the theft of oil from the pipelines "had reached levels that were no longer sustainable recently both from the point of view of safety for people and for the damage caused to the environment by these activities."
The Italian oil major was producing between 35,000 and 40,000 barrels of oil equivalent per day at the site and the theft and losses due to sabotage had reached up to 60 percent of production.
Nigeria is Africa's biggest crude oil producer and most of the government's revenue is based on the sector. The populations of the Niger Delta however live mostly in poverty and the area is very polluted.