UPDATE 3-Funds study RUSAL IPO, firm valued at $17-22 bln

* IPO organisers value firm at between $17 bln and $22 bln

* No firm commitment from potential investors except VEB

* BlackRock, Paulson show preliminary interest

* Pricing to take place around Jan. 21

(Adds date for IPO pricing)

By Dmitry Sergeyev and Polina Devitt

MOSCOW, Dec 25 (Reuters) - Funds BlackRock (BLK.N) and Paulson (PLCC.O) may buy into Russia's RUSAL, valued at $17-$22 billion by banks for an IPO, but the aluminium giant has yet to win firm commitments from non-Russian investors, sources said.

A banking source, who asked not to be named because he is not allowed to comment publicly on the issue, said on Friday RUSAL's initial public offer (IPO) bank-organisers have valued the firm at $17-$22 billion.

"Valuations differ widely but the core bookrunners showed a tighter range between $17 billion and $22 billion," the source said, adding that a maximum valuation was at around $30 billion while the minimum at $15 billion.

A second source close to the deal told Reuters more than five global investment funds, including BlackRock, Paulson and an unnamed Chinese fund have given a preliminary agreement to take part in the IPO, which is off limits for ordinary investors. [ID:nTOE5B60DM]

But the banking source said the organisers have so far not received any firm commitments from investors except for Russian state bank VEB, which plans to buy nearly a third of the 10 percent of shares on offer. [ID:nGEE5B60XE]

"As of yesterday only VEB showed firm commitment to buy RUSAL's shares during the IPO. Of course, the company wants to sell to as many investors as it can, but it so far remains wishful thinking," the source said.

Vedomosti business daily reported on Friday quoting industry sources as saying the company's board had backed the proposed valuation range and that investment fund China Investment Corporation and BlackRock may take part in the IPO.

The proposed valuation, based on recommendations of the IPO organisers, will make UC RUSAL the world's most expensive aluminium company. The market capitalisation of its competitor Alcoa (AA.N) stood at $15.6 billion, according to Reuters data.

Sources said RUSAL plans to start pre-marketing on Jan. 5 and the roadshow on Jan. 11 with the pricing expected on Jan. 21.

Vedomosti said RUSAL would split the existing 13,500 shares into 1.35 billion shares ahead of the offering, suggesting the price per share would be at $13.7-$18.9, according to the proposed price range. (Reporting by Dmitry Sergeyev and Polina Devitt, Writing by Dmitry Zhdannikov; Editing by Mike Nesbit)