* First-quarter adjusted earnings $0.42/share vs est $0.40
* Revenue $3.11 bln vs est $3.17 bln
* Climate control systems revenue down 3 pct
* Industrial technologies sales down 1 pct
April 23 (Reuters) - Ingersoll-Rand Plc, the maker of Trane air conditioners, Schlage locks and Thermo King refrigeration units, reported lower-than-expected quarterly revenue due to weak demand for its heating and cooling systems and industrial products.
Sales at its biggest business, which makes heating and cooling systems for homes and businesses, declined 3 percent to $1.62 billion in the first quarter. Overall revenue was down 1 percent at $3.11 billion, the sixth straight quarter of year-over-year revenue decline.
Ingersoll, which gets a high proportion of its business from the building sector, has not yet benefited from a recovery in U.S. construction as its climate control and security systems get fitted only towards the end of a project.
Revenue from its industrial technologies business, its second biggest, also fell 1 percent.
"We anticipate a continued macro-economic environment of low revenue growth throughout 2013," Chief Executive Michael Lamach said in a statement.
The company earned 42 cents per share in the first quarter, after excluding restructuring and one-time charges of 11 cents per share. Analysts on average had expected earnings of 40 cents per share on revenue of $3.17 billion, according to Thomson Reuters I/B/E/S.
Net income attributable to the company fell 8 percent to $88.0 million, or 29 cents per share, from $95.6 million, or 31 cents per share, a year earlier. First-quarter operating margins fell to 6.2 percent from 6.7 percent a year earlier.
The company has been trying to restructure its operations to protect its margins even as sales drop. It said in December it would spin off its commercial and residential security businesses.
Ingersoll-Rand's shares have risen 12 percent so far this year, above the broader Standard & Poor's 500 index, which has risen 3 percent. The company's shares closed at $54.00 on the New York Stock Exchange on Monday.