Caterpillar Inc. says its second-quarter profit soared 67 percent because of growing demand for its construction and mining equipment, and the company boosted its outlook for the year.

Shares jumped $3.63, or 4.5 percent, to $85.06 in premarket trading.

Caterpillar is the world's largest maker of construction and mining equipment, and its results are watched closely because they are considered an indicator of industrial activity and the health of the overall economy. CEO Doug Oberhelman said Caterpillar is prepared to cut costs if the economy does weaken significantly, but he remains cautiously optimistic, despite widespread fears of a slowing global economy.