* FY net profit up 20 pct at $1.72 bln
* Weak prices hit revenue, EBITDA
* Iron ore output down 0.9 pct to 39.8 mln tonnes
MOSCOW, April 2 (Reuters) - Russia's largest iron ore miner Metalloinvest said on Tuesday net profit rose 20.4 percent to $1.72 billion in 2012 after the sale of its railcar unit and other one-offs compensated for flagging prices.
The firm blamed a decline in iron ore prices in the second half of the year for the 17.4 percent drop in full-year revenue to $8.19 billion. Earnings slumped 34 percent to $2.55 billion.
The firm, controlled by the country's richest man, Alisher Usmanov, said the rise in net profit was partly due to its sale of Metalloinvesttrans for $369 million.
Demand for iron ore, a key steelmaking raw material, has been hit by a growth slowdown in China and the impact of Europe's debt crisis on construction and industrial production.
"Despite the challenging world economic situation and continued market volatility, Metalloinvest demonstrated robust financial and operational results for 2012, maintaining its leading industry positions in Russian ferrous sector," said Chief Executive Eduard Potapov.
Metalloinvest paid $126 million in June 2012 to bump up its share in Russian miner Norilsk Nickel, the world's largest nickel and palladium miner, to 4.0 percent from 3.6 percent.
Iron ore output fell 0.9 percent to 39.8 million tonnes in 2012, the company said, citing maintenance work carried out during a period of falling prices in the fourth quarter.
Metalloinvest intended to go public in 2008 but cancelled its plans due to the financial crisis.