BOLOGNA, Italy (Reuters) - French environment and energy minister Nicolas Hulot said on Monday that the government plans to close some nuclear reactors of state-controlled utility EDF EDF.PA to reduce nuclear's share of the country's power mix.

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He gave no indication of timing.

Hulot told reporters at the G7 environment summit in the Italian city of Bologna that it was too early to give numbers about France’s aim to reduce the share of nuclear in its power generation to 50 percent from the current 75 percent.

“We are going to close some nuclear reactors and it won’t be just a symbolic move,” he said.

EDF shares, which were down 0.8 percent before Hulot’s comments, immediately fell further to stand 2.2 percent lower.

Asked about the possibility of introducing a carbon tax, Hulot said “France already has a carbon tax which we increase every year. At an EU level we want to increase the threshold,” he said.

Hulot’s predecessor as environment minister, Segolene Royal, said in May last year that France would unilaterally introduce a carbon price floor of about 30 euros ($33) a ton with a view to kick-start broader European action to cut emissions and drive forward the December 2015 United Nations-led international climate accord.

However, the socialist government quietly dropped that plan toward the end of last year as unions protested that it would lead to coal plant closures.

EDF Chief Executive Jean-Bernard Levy has repeatedly called for a minimum carbon price of between 30 euros and 40 euros per ton in France and Europe, which would boost the company’s carbon-free nuclear power stations.

Carbon prices under the European Emissions Trading System, which charges companies for each ton of carbon dioxide they emit, have fallen to about 5 euros a ton from about 30 euros in 2008 because of a glut of permits. FEUAc1