PITTSBURGH (AP) -- Aluminum producer Alcoa Inc. says its third-quarter earnings plunged 52 percent due to sharply lower prices, weaker demand and higher costs.

The Pittsburgh-based company earned $268 million, or 33 cents per share, for the three months ended Sept. 30, compared with $555 million, or 63 cents per share, a year earlier. The earlier amount included a net gain of 25 cents per share for Alcoa's sale of its stake in Aluminum Corporation of China Ltd., also known as Chalco.

Revenue edged down 2 percent to $7.23 billion from $7.39 billion in the third quarter of 2007.

Analysts polled by Thomson Financial, on average, expected profit of 50 cents per share on revenue of $7.23 billion. Those estimates typically exclude one-time items.

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