Russia may buy into RUSAL IPO -source

* State bank VEB may buy up to 3 pct of firm - source * Deal would value aluminium giant at up to $21 bln MOSCOW, Nov 19 (Reuters) - Russia may subscribe to shares in aluminium group UC RUSAL in a placement later this year, a government source told Reuters on Thursday, signalling fresh state support to the firm's indebted owner Oleg Deripaska. The source said state banking agent VEB was prepared to buy up to 3 percent of RUSAL for between 14 billion roubles ($487.6 million) and 18 billion, valuing the world's largest aluminium firm at between $16.25 billion and $20.9 billion. The board of VEB, chaired by Prime Minister Vladimir Putin, will on Thursday consider whether to allow the bank to take money from the National Welfare Fund to invest in RUSAL's IPO. VEB is managing some of the money of the fund, which is meant to invest windfall oil revenues for future generations. RUSAL -- more than 50 percent owned by oligarch Deripaska -- has struggled amid falling prices and demand for aluminium during the global financial crisis, but the Russian government has signalled its willingness to help out one of the country's biggest employers. RUSAL is hoping to raise around $2 billion from a stock market flotation in Hong Kong and Paris to help pay down its mammoth debt pile, but can only go ahead with the move if it strikes a debt restructuring agreement with around 70 international lenders. The group's debt stands at around $16.8 billion -- including $7.4 billion to non-Russian banks -- but the restructuring talks remain unresolved. RUSAL is hoping to attract major Chinese investors as well as VEB to agree to take part in the float before a global investor roadshow takes place, according to sources. (Reporting by Darya Korsunskaya; Writing by John Bowker/Robin Paxton; Editing by David Holmes)