The monopoly held by state-controlled Gazprom on the right to export Russian gas by pipeline was described as "unshakeable" by an aide to President Vladimir Putin on Wednesday.
Gazprom has the sole right to export gas via pipelines and has secured a $400 billion deal to ship gas to China over 30 years. Other companies, including Kremlin-controlled Rosneft , have said they would also like to ship gas eastwards.
Vedomosti newspaper this week quoted an order from Putin as saying the government should consider allowing producers other than Gazprom to export gas from new fields in east Siberia and Russia's far east.
But Kremlin economic adviser Andrei Belousov said Gazprom would retain the exclusive rights for selling gas abroad via pipelines.
"Gazprom's monopoly on (pipeline) network gas exports remains unshakeable," Belousov told reporters.
Gazprom, which supplies a third of Europe's gas needs, lost the exclusive right to export liquefied natural gas (LNG) in legislation signed by Putin at the end of last year.
Belousov said producers other than Gazprom may take part in a consortium to expand the gas pipeline network.
"Those are strategic issues, which are not connected to depriving Gazprom of the monopoly," he said.
(Reporting by Darya Korsunskaya; writing by Vladimir Soldatkin; editing by Jane Baird)