Alcoa Inc., the world's third-largest aluminum producer, ushered in the second-quarter earnings season by posting a 24 percent earnings decline as rising production costs eroded profits, but the results still exceeded analysts' expectations.

Alcoa, the first of the Dow Jones industrials to report earnings this quarter, said Tuesday it earned $546 million, or 66 cents per share, for the three months ended June 30, compared with $715 million, or 81 cents per share, in the year-ago period.

Quarterly revenue dropped about 6 percent to $7.62 billion.