UNITED STATES - APRIL 21:  Caterpillar Inc. heavy machinery is operated at a construction site in Denver, Colorado, U.S., on Tuesday, April 21, 2009. Caterpillar Inc., the world's largest maker of bulldozers and excavators, posted second-quarter profit that exceeded analysts' estimates as stimulus programs and improved credit markets helped stabilize demand. Net income dropped to $371 million from $1.11 billion a year earlier.  (Photo by Matthew Staver/Bloomberg via Getty Images)