PITTSBURGH — Alcoa Inc. ushered in earnings season by reporting a 3 percent profit rise despite slumping revenue, as the aluminum producer's sale of a stake in a Chinese aluminum company helped lift results.

The sale and other cash-generating moves helped lead Alcoa, the first Dow Jones component to report third-quarter earnings, to expand its stock repurchase program to 25 percent of its outstanding shares.

Alcoa posted earnings of $555 million, or 63 cents per share, for the period ended Sept. 30, up from $537 million, or 61 cents per share, during the same period last year.

The company said its earnings were weighed down by charges from asset sales and restructuring, higher petroleum and energy costs, and other expenses.

Quarterly revenue slid more than 3 percent, to $7.39 billion from $7.63 billion last year. Contributing to the decline was the exclusion of Alcoa's soft-alloy extrusion business — part of a joint venture.

The results fell short of Wall Street expectations. Analysts polled by Thomson Financial had predicted earnings of 65 cents per share on $7.40 billion in revenue.

Alcoa released the financial results after markets closed. The company's shares rose $1.42, or 3.7 percent, to close at $39.72, then gained 17 cents in after-hours trading.

In a conference call with analysts and reporters, Alcoa's chairman and chief executive, Alain Belda, said a seasonal slowdown in Europe, the softening of key U.S. markets, pressure from energy costs, the weakening dollar and lower metal prices weighed on the results. But the company continues to focus on improving productivity, gaining market share and introducing new products, he said.

Alcoa's board on Monday authorized the repurchase of up to 25 percent of the company's outstanding common stock — about 217 million shares worth about $8.6 billion.

That broadened an earlier plan to buy back 10 percent of the company's shares. Alcoa had bought back 43 million shares, or about 5 percent, by the end of the third quarter under the previous plan.