NEW YORK — A gloomy outlook from Caterpillar, the world's largest construction equipment company, is helping to send stock indexes mostly lower in midday trading.

Caterpillar said Wednesday that its earnings fell 43 percent in the second quarter as China's economy slowed and commodity prices sank.

Apple led a rise in technology stocks after beating analysts' estimates for quarterly earnings.

Shortly before noon, the Dow Jones industrial average was down eight points, or less than 0.1 percent, to 15,560.

The Standard & Poor's 500 index was down two points, or less than 0.1 percent, at 1,690.

The technology-heavy Nasdaq composite index climbed 16 points, or 0.5 percent, to 3,596.

AT&T fell 2.3 percent to $34.98 after its costs surged in the latest quarter. The company spent heavily on subsidizing smartphone sales.