UPDATE 1-Russia's Metalloinvest plans autumn IPO

(Changes source, adds details)

MOSCOW, May 20 (Reuters) - Metalloinvest, a Russian iron ore and steel company owned by billionaire Alisher Usmanov, plans to float up to 25 percent of its shares in an initial public offer in the autumn, sources close to the deal said on Tuesday.

The sources told Reuters that Metalloinvest had picked Merrill Lynch, Credit Suisse, Deutsche Bank and Renaissance Capital to organise the placement, which is expected to take place either in New York or London.

Vedomosti business daily said earlier on Tuesday that Metalloinvest hoped to raise around $3 billion initially by offering a 10 percent stake.

Its existing shareholders will sell another 15 percent of the company in proportion to their current stakes, it said.

Sources close to the deal told Reuters the structure of the placement had not yet been decided upon.

Metalloinvest declined to comment on the report.

Metalloinvest manages the assets of holding group Gazmetall, which includes Russia's two largest iron ore mines and two steel mills that rank the company fifth in terms of output.

Metalloinvest is 50 percent owned by Usmanov, with two other Russian businessmen, Andrei Skotch and Vasily Anisimov, holding 30 and 20 percent, respectively.