WASHINGTON — US heavy machinery giant Caterpillar boosts its outlook Tuesday as the global recovery gains traction.

The company's second quarter sales were $11.33 billion, outstripping market estimates.

Caterpillar also raised its 2017 revenue projection in the range of $42-44 billion from an earlier projection of $38-41 billion in April.

Sales gains in the second quarter were driven by construction in China, demand for aftermarket parts in mining and energy industries, the company said. The projected 2017 revenue will mark the first increase in annual sales since 2012.

"While a number of our end markets remain challenged, construction in China and gas compression in North America were highlights in the quarter," Caterpillar Chief Executive Officer Jim Umpleby said in a statement Tuesday.

China's economy expanded in the second quarter at a better-than-expected pace of 6.9 percent year-on-year. The International Monetary Fund (IMF) on Monday revised up China's growth forecast for 2017 and 2018 to 6.7 percent and 6.4 percent respectively.

"Mining and oil-related activities have come off of recent lows, and we are seeing improving demand for construction in most regions," Umpleby added.