Russia is set to proceed with the planned auction of Yukos's main asset on Sunday, despite a US court order blocking the sale of the Russian oil group's Yuganskeftegas unit and doubts over the availability of finance for Gazprom, the leading bidder.

A ?10bn ($13.3bn) loan which had been pledged to Gazprom to help finance the bid was effectively frozen on Friday after a bankruptcy court in Houston granted a request from Yukos for a 10-day restraining order against Gazprom and its lenders.