US-based global aluminium producer Alcoa Inc revealed on Friday that it saw dipping net income in the third quarter of the current year as volatile foreign exchange and strong energy costs were cited by the company as main contributor to its 21 percent profit slide.

Alcoa reported that its net income for the three-month spread ending in September 30 plunged by 21 percent to $US61 million or $A62.4 million as compared to the $US77 million earned in the same period in the prior year.

The profit decline, according to the company, led to a six cents per share retreat of net income for the same period as against the eight cents per share posted in the same quarter in 2009 though Alcoa's revenue jumped up in the process as it gained by 14.6 percent to $US5.3 billion.

Alcoa's financial report is one of the first to come out in the quarter and economists regularly utilise the company's data as gauge for initial signs on the health of the economy and the latest numbers surpassed market's expectations of $US4.95 billion revenue or five cents per share pick ups.

Company chair and chief executive Klaus Kleinfeld said that beating out market expectations prompted the company to believe that global recovery was indeed underway as he revealed that forecast for aluminium consumption spiked from 12 percent to 13 percent for calendar year 2010.

Mr Kleinfeld said that the middle class has been growing in Brazil, China, India and Russia, which he pointed out were fuelling further demands in building, construction, transportation and packaging, leading to an environment that "favours aluminium as it is light, strong, and infinitely recyclable."

Alcoa said that while aluminium prices moved by 15 percent year-over-year to $US2261 per metric tonne, the company's net income was still pushed down by increasing foreign exchange costs, energy costs and other miscellaneous expenditures.

Analysts said that since major consumers of aluminium such as auto makers and industrial producers have already secured supply contracts way into 2012, no considerable upward surge in prices could be expected though related products may see some movements if aluminium prices gain traction in the next few quarters.