NIAMEY/PARIS, June 20 (Reuters) - Niger plans to

nationalise the Somair uranium mine operated by France's Orano

after months of worsening relations between the French

state-owned company and its local partners following a 2023 coup

in the West African nation.

Niger's decision to nationalise Somair comes amid a wave

of mine nationalisations across West Africa, prompting concerns

from global miners and other foreign investors who have invested

billions of dollars into the region.

In a statement late on Thursday, Niger accused the French

company of taking a disproportionate share of the mine's

commercialised production compared to its shareholding.

"According to the shareholders' agreement, the uranium

produced by SOMAÏR is removed by the shareholders in proportion

to their respective stakes. However, the figures....are far from

reflecting this sharing rule," the statement said.

Orano holds a 63% stake in Somair, while Niger's state-owned

Sopamin owns the remainder, but the government said Orano had

taken 86.3% of production between 1971, when the mine was

launched, and 2024, without elaborating.

It also accused Orano of what it called "irresponsible,

illegal and unfair" behaviour pointing to the company's decision

to withdraw French nationals working on the project, disconnect

it from the group's IT system, and halt production at the mine.

Orano declined to comment on Niger's plans to nationalise

Somair. It did not immediately respond to a request for comment

on the government allegations.

Orano has been pursuing arbitration against Niger and

filed lawsuits in the country against state actions, and had

warned of government interference at Somair, which it said was

damaging the mine's financial situation.

It was exploring a potential sale of its stake in Somair,

after Niger blocked uranium exports from the mine and took

control of it, according to a Financial Times report in May.

The government seized control of the mine in December.

In neighbouring Mali, Canada's Barrick Mining ( B ) had

its Loulo-Gounkoto gold complex placed under state control by a

court on Monday in a major escalation of a dispute over taxes

and ownership.

Burkina Faso has also nationalised five gold mines this

month.