Caterpillar Inc (CAT.N) on Tuesday reported a sharply lower third-quarter profit after global economic weakness and an abundance of available used equipment slowed sales of its new machinery.

The world's largest construction and mining equipment maker also lowered its full-year revenue outlook for the second time. It now expects about US$39 billion, down from a range of US$40.0 billion to US$40.5 billion.

The company expects its challenges to persist into next year, Chief Executive Officer Doug Oberhelman said in a statement.

"In North America, the market has an abundance of used construction equipment, rail customers have a substantial number of idle locomotives, and around the world there are a significant number of idle mining trucks," Oberhelman said.

Caterpillar forecast 2016 profit at US$2.35 per share, or US$3.25 excluding restructuring costs.

The company again raised expectations of 2016 restructuring costs, to $800 million from a previous estimate of US$700 million.

Shares of Caterpillar were down 1.7 per cent at US$84.55 in premarket trading.

Caterpillar reported a third-quarter profit of US$283 million, or 48 cents per share, down from a revised $559 million, or 94 cents per share, a year earlier.

Excluding restructuring costs, earnings per share were 85 cents.