Alcoa ( AA - Get Report) said late Tuesday that quarterly profit grew by 85% over the previous year, but sales were a shade shy of analysts' projections.

Following the announcement, shares of Alcoa fell $1.79, or 6.3%, to $26.50 in recent after-hours trading.

For the third quarter, Alcoa earned $537 million, or 61 cents a share, up from $289 million, or 33 cents a share, in the same period last year.

The aluminum company said it recorded a tax benefit of $18 million during the quarter from to a correction in deferred tax assets related to an international location. During the quarter, the company's tax rate was 24.7%.

According to Thomson First Call, analysts anticipated an EPS of 77 cents, but it was unclear if the figure is a direct comparison.

Alcoa posted revenue $7.63 billion, rising from $6.4 billion a year ago. Analysts were expecting revenue for the quarter of $7.75 billion.

"In July, we said the third quarter would be solid, but would reflect the traditional seasonal slow-down and lower metal prices. In fact, the quarter was the third best in company history even though metal prices on the London Metal Exchange declined 6%," Alain Belda, Alcoa chairman and CEO, said in a statement.

"While the North American automotive and the housing construction markets are softening, most of our downstream markets continue to be strong -- especially aerospace and commercial transportation," he added.

The company did not provide any immediate guidance.