Sberbank may cover RUSAL repayment to Alfa-sources

* Alfa had threatened several RUSAL units with bankruptcy * Loan may yet need approval from Sberbank credit committee MOSCOW/LONDON, Sept 29 (Reuters) - Sberbank, Russia's top state bank, is expected to step in with a loan to cover aluminium giant UC RUSAL's controversial decision to pay off a single Russian creditor, sources close to RUSAL debt talks said. A spokeswoman for UC RUSAL, which announced the repayment to privately owned Alfa-Bank last week, said on Tuesday the company, which is majority owned by indebted billionaire Oleg Deripaska, had repaid Alfa from its own cash resources. The world's largest aluminium company has outraged members of a 70-strong creditors' club, working on a deal to restructure $7.3 billion of RUSAL's foreign debt, by repaying Alfa ahead of other lenders, sources close to the talks said. Sberbank was not immediately available for comment. UC RUSAL's creditors have appealed for Kremlin help at tricky moments in the restructuring talks but have largely been met with silence. The size of the loan from Alfa was small, at $85.9 million, but its repayment caused consternation because it followed Alfa's threat to bankrupt two UC RUSAL units and broke the ranks of UC RUSAL's creditors. The aluminium producer owes a total of about $16 billion to Russian and foreign banks. The loan may have yet to clear Sberbank's credit committee, said one of the sources, who spoke on condition of anonymity. "Alfa played that classic card of the small creditor faced with a global restructuring which they couldn't themselves afford -- though they could afford a global bankruptcy even less -- and pressed the nuclear button," the source said. "Result: Alfa gets repaid in full with acquiescence from other creditors, who simply want the barbarians to withdraw from the gates." (Reporting by Melissa Akin and Polina Devitt in Moscow and Christopher Mangham in London; editing by Simon Jessop)