It said Q4 earnings before interest, tax, depreciation and amortisation, stripping out Norilsk, fell 46% to $382M, while its full year earnings were down slightlyIt forecast near-term pressure on aluminium prices, which fell sharply in late 2011, due to global volatility

The company on Sunday threatened to sue former chairman Victor Vekselberg, saying his comments had damaged its reputation and shareholder value, and named Hong Kong Mercantile Exchange chairman Barry Cheung as its new chairman.

Vekselberg quit as chairman last week in a row over strategy with Oleg Deripaska, the main shareholder and another Russian billionaire.

The boardroom row has highlighted a dispute over how to relieve the company of an $11bn debt burden inherited from its $14bn purchase of a quarter of Norilsk Nickel at the top of the market in 2008. Vekselberg wants to sell the stake back to Norilsk but has been consistently overruled by Deripaska.

Rusal posted a net profit of $237M for 2011 against $2.87bn a year earlier.

Rusal said its adjusted net profit, which it described as the major indicator of its core business, rose 25% to $987M from $792M in 2010 due to lower debt costs.

Its aluminium output edged up 1% to 4.12Mt in 2011 and output of alumina rose 4% to 8.15Mt.

Rusal said it planned to cut aluminium production by 6%, but did not give a time frame. The company said in February it may introduce a 6% cut over 18 months.

It has forecast 6-8% of global capacity will be shut in the first half of 2012 and that could help make the market more balanced this year, it said.