Oct. 3 (Bloomberg) -- Royal Dutch Shell Plc, Europe's biggest oil company, said oil spills in Nigeria caused by sabotage jumped 47 percent last year.

A total of 18,500 barrels of crude were spilled into the environment in 2007 in ``221 incidents of sabotage and vandalism to pipelines, flow lines and manifolds,'' Shell said on its Web site. That compared with 12,600 barrels of crude spilled in similar incidents the previous year.

Sabotage accounted for two-thirds of total spills in Shell's operations in the West African nation last year, with equipment failure, corrosion or human error responsible for the remainder.

Shell Petroleum Development Co., the company's Nigerian unit, operates a joint venture in which state-owned Nigerian National Petroleum Corp. has a 55 percent stake. Shell holds 30 percent, Total SA has 10 percent and Eni SpA the remaining 5 percent.

Armed groups, including the Movement for the Emancipation of the Niger Delta, or Mend, have targeted pipelines and other installations in Nigeria's oil-producing delta in recent years, cutting more than 20 percent of the country's crude exports since 2006. Mend says it's fighting on behalf of local communities who have yet to benefit from Nigeria's oil wealth.

To contact the reporter on this story: Dulue Mbachu in Lagos via the Johannesburg bureau at abolleurs@bloomberg.net

Last Updated: October 3, 2008 11:01 EDT