Caterpillar Inc. (CAT), one of the world's largest construction equipment makers, said Friday its second-quarter profit fell 21 percent, hurt by weakness in North American construction markets.

The results missed Wall Street expectations, and Caterpillar shares skidded 4 percent lower in premarket trading.

Caterpillar earned $823 million, or $1.24 per share, in the three months ended June 30, down from $1.05 billion, or $1.52 per share during the same period last year.

Revenue rose 7 percent to $11.36 billion from $10.61 billion last year.

Analysts polled by Thomson Financial expected a profit of $1.49 on revenue of $11.12 billion.

Revenue was helped by sales outside of North America, Caterpillar said, which offset the planned decline in North American dealer machine inventories and a drop in demand for on-highway truck engines.

Caterpillar said earnings were hurt by soft North American machine sales, selected supply chain disruptions and higher material and manufacturing costs.

Its shares fell $3.48 to $83.50 in premarket trading.