United Technologies Corp., the world's largest maker of elevators and air conditioners, raised the bottom end of its 2013 earnings forecast on Tuesday, citing its growing confidence after a jump in customer orders and round of cost cuts.

The company, which also makes Pratt & Whitney jet engines and Black Hawk helicopters, said orders for large commercial engine parts jumped 65 percent in the second quarter, a bump largely attributed to last year's $16.5 billion acquisition of parts maker Goodrich, the largest in United Tech's history.

The deal, though criticized as expensive at the time, has helped United Tech become the preeminent supplier of parts to aerospace customers, offering a suite of services previously supplied by many rivals.

Roughly 65 percent of an airplane's components now come from United Tech, estimates William Blair & Co analyst Nick Heymann.

The company posted income of $1.56 billion, or $1.70 per share, compared with $1.33 billion, or $1.62 per share, a year earlier.

Analysts on average expected earnings of $1.57 per share, according to Thomson Reuters I/B/E/S.

Revenue rose 16 percent to $16 billion. Analysts expected $16.37 billion.

United Tech raised the low end of its 2013 earnings forecast to $6.00 a share from $5.85 while keeping the high end at $6.15.

Wall Street expects 2013 profit of $6.11 per share.

Shares of United Tech, which closed Monday at $102.11, have gained 25 percent so far this year.