A civilian transport helicopter used in Nigeria's oil industry crashed Friday, killing the pilot, company officials said Friday.

No passengers were on board when the craft went down about an hour after dawn in southern Nigeria, said an official of the company, Bristow, which owned the helicopter that was often used to ferry oil workers around the restive region.

The pilot's nationality wouldn't be released pending notification of next of kin, the official said.

Oil industry workers contacted in the region said rain was falling heavily at the time of the crash, which the Bristow official said was under investigation.

Helicopters have taken on an increasing role in transporting oil workers amid rising insecurity in southern Nigeria, where all of Nigeria's crude is pumped. More than 150 foreigners have been kidnapped in Nigeria this year alone, with many taken from their vehicles as they traveled on the region's roads.

But Nigeria's aviation industry has also had troubles. Hundreds of people have died in aircraft accidents over the past three years, with analysts blaming poor maintenance and untrained ground crews.

A civilian helicopter crash in November killed one person and injured three others. In April, a military helicopter crashed in heavy rains as it helped deliver voting materials around the country.

Copyright (c) 2007 Dow Jones & Company, Inc.