Swiss banks UBS and Credit Suisse are interested in advising the Russian government on several privatization efforts as long as the deals do not violate sanctions, three banking sources told Reuters. A fourth source said Italy's UniCredit had also answered the proposal.

The banks responded to a request for proposals that the Russian Economy Ministry sent to Russian and foreign banks this month for advisory roles in the planned sales of a 50.08 percent stake in oil firm Bashneft and 10.9 percent stakes in both diamond miner Alrosa and lender VTB.

Bankers previously told Reuters that Western investments banks with Russian operations are reluctant to advise Moscow on planned privatizations as they are worried about the consequences of violating Western sanctions imposed on Russia over the conflict in Ukraine.

Western banks that received proposals included Goldman Sachs, JP Morgan, Citi, Morgan Stanley, Deutsche Bank, Barclays and BNP Paribas.

The EU financial sanctions do not explicitly prevent European firms from advising on most Russian transactions. But some of the measures include grey areas that are open to interpretation.