Commodity trader Mercuria has asked the US Treasury for permission to buy out a $1.5bn loan between Russia’s Rosneft and Venezuela’s state oil company, which had raised the prospect of Moscow taking control of refineries on US soil. The cash-strapped Venezuela state oil company PDVSA, which has borrowed more than $6bn from Kremlin-controlled Rosneft, caused consternation in Washington last year after putting up a stake in its US-based refining subsidiary, Citgo, as collateral against a portion of the loan. The move by Switzerland-based Mercuria would see the trader put up the money to buy out the $1.5bn loan tied to Citgo, before syndicating it to other investors, according to people familiar with the proposal. If approved by the US Office of Foreign Assets Control (Ofac), the deal could avoid a potential diplomatic tangle in the event that PDVSA defaults on its loans, with the US seen as unlikely to approve Rosneft taking over the 49.9 per cent stake in Citgo’s plants. Both Russia and Venezuela are subject to US sanctions, with Rosneft and PDVSA executives singled out for attention from the Treasury. Rosneft would face an uphill struggle to get approval to exercise a stake in Citgo so this avoids a potential diplomatic strain between the US and Russia Richard Mallinson, geopolitical analyst at Energy Aspects