Moscow-based Alfa Bank has launched a legal case against Oleg Deripaska, the Russian oligarch last year ranked as the country’s richest man, in a bid to protect itself against the possible default of a $1bn (€780m) loan. It comes as Deripaska faces a struggle to restructure his outstanding debt to other creditors.

Alfa Bank, to which Deripaska's companies owe about $1bn, does not want to restructure the debt but instead would like to receive stakes in the borrower's companies as collateral, the bank confirmed.