The Chadian government has nationalised assets belonging to a subsidiary of Exxon Mobile.

It’s the latest development in a dispute between the authorities of the Central African country and the US oil giant over the sale of its assets in Chad to a third party.

The vast majority of Chad’s revenue comes from exporting oil. So when it disagreed with the terms under which Exxon sold its Chadian assets to British company Savannah Energy last year, it promised to go to court to block the purchase.

Now the Chadian authorities have gone one step further - they’ve nationalised Exxon’s assets, a move which could potentially spook foreign investors.

Savannah Energy has said it will challenge the move legally. The assets involved include a 40% stake in Chad’s Doba oil project - seven oilfields with a combined output of 28,000 barrels per day.