ABUJA, May 14 (Reuters) - Gunmen kidnapped a Nigerian manager working for Italian oil company Agip <ENI.MI> in Port Harcourt in the Niger Delta on Monday, the latest in a spate of abductions in Nigeria's anarchic oil heartland, police said. The man was on his way to work when six men dressed in military uniforms snatched him, a source working for a security company said. Ransom seekers in the Niger Delta sometimes dress up as soldiers to carry out abductions. Militant attacks on oil facilities and kidnappings of oil workers have multiplied this year in the Niger Delta, which accounts for all of Nigeria's crude exports, the eighth-biggest in the world. Attacks have cut output by a quarter while thousands of foreigners have fled. About 100 expatriates have been kidnapped this year but most have been released after their employers paid ransoms. Thirteen foreign hostages are still in captivity. U.S. major Chevron <CVX.N> said on Friday it was evacuating hundreds of non-essential staff from offshore operations due to security concerns. It said the pullout would not further impact its production in Nigeria, which has been cut by attacks. Chevron has had to cut output by 42,000 barrels per day (bpd) at its Escravos oilfields and by 15,000 bpd at its Pennington terminal this month. Agip has also been hard-hit by the violence, which is rooted in resentment at an industry that has enriched corrupt Nigerian governments for five decades but brought almost no benefits to the impoverished people of the delta. Agip has had several foreign staff abducted in the past few months and its Brass export terminal has been affected by several attacks. Last week it had to reduce volume flowing through Brass by 98,000 bpd because of pipeline bombings. Some of the violence in the delta is carried out by militant groups pressing political demands such as greater local control over oil wealth and the release of jailed leaders from the delta. But the lines are blurred with criminal gangs seeking profits from kidnappings or from the trade in stolen crude. The rebel Movement for the Emancipation of the Niger Delta (MEND), which was responsible for most of the attacks that reduced oil output, has said it had instructed fighters to cause "mayhem" in the run-up to Nigeria's political transition. Outgoing President Olusegun Obasanjo is due to hand over to president-elect Umaru Yar'Adua on May 29. But the election that gave Yar'Adua his mandate was deemed "not credible" by international observers who reported widespread vote-rigging. This has caused anger in the Niger Delta, where many residents already felt disenfranchised because their region has suffered decades of neglect despite accounting for the bulk of Nigeria's wealth.
