The company also said it was generating more cash and paying down debt faster than it expected, and its shares rose nearly 2 percent.
Net earnings fell to $216.6 million, or 65 cents per share, from $227.7 million, or 70 cents per share, a year earlier.
Excluding restructuring costs, earnings from continuing operations were 70 cents per share, 9 cents higher than average analyst estimates, according to Thomson Reuters I/B/E/S.
Revenue fell 19 percent to $3.48 billion, below Wall Street forecasts of $3.56 billion.
Ingersoll's biggest segment, which provides air conditioning systems and services, reported a 14 percent drop in sales, partly reflecting a weak nonresidential construction sector. A decline in sales to residential customers was less severe.
The U.S. housing market and replacement spending remain weak, but are falling at a slower rate, Ingersoll said.
The company, which also makes security technology, air compressors and utility vehicles, said it was confident that earnings would increase next year even if markets remain weak.
With productivity gains outpacing cost inflation, Ingersoll expects to earn between $2 and $2.40 per share in 2010. Analysts were expecting $1.98.
The initial 2010 forecast was a positive surprise, said KeyBanc Capital Markets analyst Jeffrey Hammond in a research note, adding that the company's goal appears achievable.
Ingersoll narrowed this year's earnings forecast to between $1.60 and $1.70 per share, keeping the midpoint of the range the same. The analysts' average estimate was $1.58.
Separately, Ingersoll said it would reduce its debt by about $1 billion in 2009, up from an earlier estimate of $675 million. It said it would generate $1.3 billion to $1.4 billion in cash this year, ahead of its original plan of $920 million.
Ingersoll shares rose 1.8 percent, to $35.98 in morning New York Stock Exchange trading.
(Reporting by Nick Zieminski; Editing by Derek Caney)