BAGHDAD - Recurrent violence in oil-rich parts of Nigeria may provide a sobering lesson for oil companies hoping to work in Iraq - a place that is much more dangerous despite the fact that attacks are at their lowest level in more than four years.

Representatives of 35 international oil companies will meet with Iraqi government officials in London on Monday to discuss the bidding process for eight enormous oil and gas fields. If the contracts are approved, they could lead to the biggest foreign stake in Iraq since the industry was nationalized more than 30 years ago.

About 4,000 miles from Baghdad, oil companies are doing damage control in Nigeria - arguably the most dangerous place in the world where firms like Royal Dutch Shell PLC and Exxon Mobil Corp. currently operate.

Three years of attacks in the country's Niger Delta have cut oil production from 2.5 million barrels per day to around 1.5 million - demoting Nigeria to Africa's second largest oil producer behind Angola.

The violence in Nigeria pales next to Iraq, even now.

"The differential is enormous in terms of the physical threat of being killed by a militant," said Ian Pilcher, a private security consultant who has advised oil companies in both Nigeria and Iraq. "Nigerian hostages are rarely harmed, if at all, and I can't really see West Africans ever setting up roadside bombs."

The risk of death while pursuing oil in Iraq, however, comes with the potential for rich rewards.

Current estimates put Iraq's proven oil reserves at 115 billion barrels - more than three times the 36 billion barrels held by Nigeria.

Experts believe Iraq's proven reserves could rise by an additional 70 billion to 80 billion barrels once security conditions stabilize enough to allow renewed exploration. That would give Iraq the world's second-largest proven oil reserves after Saudi Arabia.

"Even if the security situation is a problem, the potential is so great that if you are a major oil company, you have to have an Iraq strategy in your portfolio," said Leila Benali, director of the Middle East and Africa department at Cambridge Energy Research Associates.

And oil companies are maneuvering to gain access.

The Iraqi government recently signed a $3 billion deal with the state-owned China National Petroleum Corp. to develop the Ahdab oil field in southern Iraq.

In September, Shell signed a deal to establish a joint venture with the state-run Iraqi South Oil Co. to tap natural gas in southern Iraq and is expected to spend $3 billion to $4 billion over five years on the project.