Russian firm Sual has refused to comment on reports that it is to merge with compatriot Rusal to create the world's largest aluminium company.
The combined group would be the world's largest aluminium firm
"We do not comment on rumours," said Sual spokesman Alexey Prokhorov in reference to the report in the country's Kommersant newspaper.
If Sual and Rusal were to merge, they would create a new national monopoly in Russia, mirroring gas giant Gazprom.
The global aluminium industry is currently led by US giant Alcoa.
Rusal, the world's third-largest aluminium firm, could not immediately be reached for comment.
Kommersant said Rusal and fellow top 10 aluminium producer Sual planned to announce their merger in October.
Rusal produced 2.7 million tonnes of the metal last year, compared with Sual's 1.05 million.
The two firms are working together on increasing aluminium production in north-west Russia.