The arrest of mining executives in Mali, threats by Burkina Faso's junta to strip permits and the seizure of a French-run uranium site in Niger have unsettled Western miners operating in West Africa and could limit further investments.

Day-to-day production in Mali and Burkina Faso has so far been largely unaffected.

The escalation is expected, however, to hit firms seeking finance and insurance - curbing supply growth in Africa's engine of gold output, more than a dozen people, including mining employees, financiers, insurance providers and government sources, told Reuters.

The push by Mali, Burkina Faso and Niger's military governments to renegotiate terms with mining companies and gain a bigger share of revenues has coincided with a surge in gold and uranium prices.

It has also followed a series of coups, starting with Mali in 2020, and the three countries' shift towards Russia and away from their traditional backers France, the United States and the United Nations.

Moscow has strengthened its military and diplomatic presence in the region. There is no evidence yet Russian companies have positioned themselves to take over mining assets, but analysts said that could not be ruled out.

"We wouldn't invest in Mali now," a Western fund manager told Reuters, adding record gold prices had made miners operating in the Sahel an obvious target for juntas. The fund manager asked not to be named.

Over the last decade, companies keen to profit from West African gold countered the spreading threats posed by Islamist militants expanding from their initial stronghold in northern Mali by working with governments to beef up security.

But relations have soured since the coups.

Mali, Africa's second biggest gold producer last year, according to the World Gold Council (WGC), carried out an audit of operations and rolled out a new mining code, triggering talks over new agreements and outstanding tax bills.

Arrests of staff from Australia's Resolute Mining and Canada's Barrick Gold by military authorities have gathered pace since September. Mali issued an arrest warrant for Barrick CEO Mark Bristow last week.

The country has so far received or been promised over $635-million in additional tax payments from various companies, Reuters calculations show.

Four Barrick Gold employees are detained in Mali's capital Bamako pending trial. Barrick, the world's No.2 gold miner, said in November it was seeking to strike a deal.

Barrick did not reply to requests for comment for this story.

CHANGED EQUATION

Home to vast, untapped gold reserves, mining investment in West Africa has surged in the last 15 years, though Mali, Niger and Burkina remain among the world's poorest countries.

Mali's gold output has more than doubled to 105 metric tons as of last year from 2010 levels, WGC data show. With Burkina Faso and Niger, it accounts for a quarter of the continent's gold production.

Mali's junta pledged to review mining contracts in 2020. Some companies, including B2Gold, signed new agreements with the government. Last month, Resolute Mining made $100 million in payments to Mali after its chief executive was detained during a visit. Mali accuses Barrick of owing up to $500 million, which Barrick denies.

A Malian government source said the new mining code seeks to address inequalities in contracts with companies without "killing the industry". Mali's mines ministry did not immediately reply to a request for comment.

In a sign of unease over Mali, Canada's Robex Resources said in September it was looking to sell its Nampala mine in Mali but it had not received any reasonable offer.

"Due to the geopolitical context for investments in Mali, the market of potential buyers is currently very limited." Robex did not respond to requests for further comment.

Insurers are more cautious about the risks they underwrite, said Gallagher's Racheal Tumelty, head of Political Risk Australia, who has previously brokered insurance for projects in Mali and other West African countries.

Premiums for some West African countries had almost trebled as of late 2023 compared to 2019, she said.

TAKING BACK PERMITS

Challenges in the Sahel did not apply to the wider region of West Africa, Jeff Quartermaine, CEO of Perseus Mining, said, so events in Mali had no impact on the Australian-listed miner's operations in coastal Ivory Coast or Ghana.

But others see warning signs for the industry.

In Niger, where the junta tore up a defence agreement with former colonial power France shortly after coming to power last year, authorities have taken control of French nuclear fuels company Orano's Somair uranium mine, the company said last week.

London-listed Endeavour Mining sold two of its gold mines to the Burkina Faso government for $60 million, having flagged an initial agreement of $300 million, company statements showed. Endeavour declined to comment about the discrepancy.

Burkina Faso junta leader Ibrahim Traore said in July he would withdraw permits from miners headquartered in countries that did not supply military equipment.

A senior official working for a mining company in West Africa said the authorities were implicitly telling Western miners that they could now turn to Moscow if they needed other mining partners.

Short term, analysts said they expected juntas to continue squeezing the companies already in the region.

"I don't think the miners are reassured. A couple of years down the line, they might find themselves being told, 'that is not sufficient'," said Vincent Rouget, an analyst at global risk consultancy Control Risks, which advises miners in the region.