Net profits for the months of July to September 2010 dropped from $64 million to $29 million compared with the same period in 2009, said the company, which began trading in Hong Kong this January with an eye for Asian markets.
Rusal swung back to profit earlier this year following a tough stretch in which the economic recession slashed demand for its products and plunged Rusal into debt.
Net profit for the first nine months of 2010 was $1.42 billion, up from a net loss of 826 million in the same period in 2010, the Rusal statement said.
But underperformance in the third quarter caused share prices to drop from a $10.30 HK opening to as low as $9.58 HK before partially recovering later in the day on the Hong Kong exchange.
Rusal is the world's largest aluminium producer, responsible for about 10 per cent of world's production of aluminium and the same share of alumina, according to last year's figures.
Last December, Rusal reached an agreement with creditors to restructure debts of some $16.8 billion US, clearing the way for a listing of its shares in Hong Kong, with the initial share price of $10.80 HK .
Total debt has now been reduced to $12.3 billion, the company said, adding that it is ahead of its debt reduction targets.
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