Lenders to Russian aluminum giant United Company Rusal, which is in talks to restructure its multibillion-dollar debt, have requested the company's clarification on how it will be able to finance its part of an ambitious Siberian project and repay its part of the loan associated with it, people familiar with the matter told Dow Jones Newswires Wednesday.

Barclays Bank PLC (BARC.LN), acting as the facility agent, sent a letter to Rusal, in which it asks the company to explain how it will be able to meet its financing obligation in respect to the Boguchansk Energy and Metals Complex, or BEMO.

Rusal and state-controlled hydropower monopoly RusHydro (HYDR.RS) are building the 3,000-megawatt plant, which is to feed the Boguchansk aluminum smelter, also jointly built by Rusal and RusHydro.

The banks, including Barclays Capital, Calyon, ABN Amro Bank and Russia's Sberbank (SBER.RS), have lent $520 million to the BEMO partners as a bridge loan.

In its letter, Barclays asked Rusal how it will be in a position to repay its 50% share of the loan on the maturity date in early 2010.

The letter also asks Rusal to give its rationale for the continuation of the project, given Rusal's production cuts and its previous statements that the smelter launch had been indefinitely suspended.

-By Alexander Kolyandr, Dow Jones Newswires; +44 20 7842 9410; alexander.kolyandr@dowjones.com