The Finnish utility said in May 2022 it would "pursue a controlled exit" from the country, joining a long list of firms seeking to leave after Russia sent troops into Ukraine in February 2022.

"Completing the exit is likely to take further time and there still are significant uncertainties - including regulatory approvals - related to the ongoing divestment process," Fortum said in February 2023.

Kostin, speaking in an interview broadcast on the Rossiya-24 television channel, said Russia needs to attract as much private money as possible and could offer non-controlling stakes in large state firms to investors as part of a privatisation drive.

Kostin said Russia should consider taking over foreign companies' assets, a process that he said would mirror restrictions imposed on Russian assets abroad.

VTB was forced to shutter its European operations as sanctions were imposed.

"We were told that (our German subsidiary) no longer had the right to operate," Kostin said, explaining that the unit was put into administration, with its assets to be sold and anything left to be frozen until sanctions are removed.

Kostin named Fortum as an example of a large foreign company whose assets could be targeted.

"Why not, say, take it over? Give it to some managerial company like Interrao," Kostin said. "Let them manage it and pay the government money for it.

"And when the sanctions are over, we will give it back to them. It's only fair."

(Reporting by Elena Fabrichnaya; Writing by Alexander Marrow; Editing by Gareth Jones)

By Elena Fabrichnaya and Alexander Marrow