"The force majeure on Forcados loading was lifted... Thursday, while that of Bonny had been lifted earlier on November 21," Shell spokesman in Lagos Precious Okolobo told AFP.

Force majeure is a legal term releasing a company from contractual obligations due to circumstances beyond its control.

Shell's Nigerian subsidiary had suspended loadings at Bonny and Forcados on October 19 because of theft, flooding and damage to the supply pipelines.

Pipeline damage and associated spills are common in the Niger Delta region as a result of oil theft to feed the lucrative black market.

Militants claiming to be fighting for a fairer distribution of oil revenue have also regularly blown up pipelines, though such attacks have decreased since a 2009 amnesty deal.

Although Shell did not disclose the volume of crude exports affected by the shut-down, industry sources said both Bonny and Forcados account for substantial percentage of Nigeria's total oil exports.

Nigeria is Africa's largest oil producer, exporting between two and 2.4 million barrels per day in recent months.