By Scott Malone

BOSTON (Reuters) - Diversified U.S. manufacturer United Technologies Corp (UTX.N: Quote, Profile, Research) reported profit that topped Wall Street's expectations on Thursday but its shares fell in early trading after the company held its full-year outlook steady and warned of a slowing economy.

The company attributed the 22 percent rise in first-quarter profit to strong demand for aviation equipment, as well as elevators and air conditioners used in commercial buildings. But it noted "early signs" of slowing growth in the United States and Europe.

"As we look to the back half of the year, we continue to adjust our operations in anticipation of the uncertain economic environment," Louis Chenevert, who last week succeeded George David as CEO.

Last week fellow blue-chip industrial General Electric Co (GE.N: Quote, Profile, Research) cut its 2008 profit outlook, citing weakness in its financial services business.

United Tech, which makes products ranging from Otis elevators to Black Hawk military helicopters reported profit of $1 billion, or $1.03 per share, compared with $819 million, or 82 cents a share, a year earlier.

Factoring out 2 cents per share of restructuring charges, profit was $1.05 per share. On that basis, Wall Street had expected, on average, $1.01 per share, according to Reuters Estimates.

Revenue rose 11.6 percent to $13.7 billion.

"UTX pumped out another very solid quarter," Nigel Coe, analyst at Deutsche Bank, wrote in a note to clients, referring to the company by its stock symbol. "The outlook remains cautious."