Exxon Mobil Corp. ended exploration plans with Total in South Sudan, Total and the government said, a sign of faltering investor confidence in the African nation as a civil war enters its eighth month.

Exxon Mobil in April didn’t renew an agreement with Total to negotiate for joint-exploration over parts of a 120,000 sq km (46,300 sq mile) concession in Jonglei state, Total spokeswoman Anastasia Zhivulina said in an Aug. 12 e-mailed response to questions. Total is still bidding to explore in partnership with Kuwait’s state-owned Kuwait Foreign Exploration Petroleum Co. she said. Exxon Mobil spokesman Patrick McGinn said by e-mail that the company doesn’t comment on specific ventures.

“Losing the American oil company’s interest is definitely a blow for the future prospects of South Sudan’s oil industry,” Luke Patey, a researcher on the country’s industry at the Danish Institute for International Studies, said in an e-mailed response to questions. Exxon Mobil could re-enter South Sudan when security improves, he said.

Crude oil output, South Sudan’s almost sole source of revenue, has fallen by at least a third to about 160,000 bbl/d since conflict erupted in December and the army battled rebels in two oil-producing states.

Projects suspended

The conflict, which has left thousands dead, led to the evacuation of some staff by the country’s main oil producers including China National Petroleum Corp. and India’s Oil & Natural Gas Corp. The former head of U.S. security company Blackwater Security Consulting LLC, Erik Prince, suspended plans to build an oil refinery in the north of the country due to the violence.

Petroleum Ministry spokesman Nicodemus Ajak Bior said in an e-mail that he was aware of Irving, Texas-based Exxon Mobil’s “pull out.”

Total, which is based in Paris, has held the Block B concession in Jonglei state, near South Sudan’s eastern border with Ethiopia, since 1980 when it was part of a united Sudan. Recurrent violence has hampered exploration and there have been no proven oil finds.

In September 2012, the government divided the block into three. Exxon Mobil is pulling out of its agreement to jointly-explore two of them, Zhivulina said. The outbreak of war in South Sudan meant Total and the Kuwaiti company’s October offer for Blocks 1 and 2 hasn’t been approved by the government, she said.

Man-made famine

Upper Nile state is the only region of South Sudan still pumping oil eight months after violence began between