PARIS, Dec 20 (Reuters) - French nuclear fuels company

Orano said on Friday it had started arbitration proceedings

against Niger, after Niger withdrew the mining licence of

Orano's subsidiary Imouraren.

Niger's military-led government has stepped up pressure in

recent months on foreign investors. A representative for the

government did not immediately respond to a request for comment.

Orano said in June that Niger had removed the mining permit

for Imouraren, and the following month Canada's GoviEx Uranium ( GVXXF )

said it too had been stripped of its right to develop a

uranium project in Niger.

Earlier this month, Orano said authorities in Niger had

seized control of its

Somair uranium mine

.

Niger accounts for about 4% of global output of uranium,

the most widely used fuel for nuclear energy.

Barrick Gold said on Wednesday it

would initiate arbitration

in its dispute with neighbouring Mali.