One of Russia’s richest men is attempting to secure a multi-billion dollar loan from state-controlled bank VTB after being hit with a margin call by Dresdner Bank, which will force him to hand over a stake in gas monopoly Gazprom unless the debt can be refinanced.

Alisher Usmanov is attempting to secure a loan from VTB to regain a 1.5% holding in Gazprom that was posted as collateral against a loan from Dresdner, according to Russian daily Vedomosti.